Acute toxicity of Corexit EC9500A and assessment of dioctyl sulfosuccinate as an indicator for monitoring four oil dispersants applied to diluted bitumen.

PubMed

MacInnis, Ceara Y; Brunswick, Pamela; Park, Grace H; Buday, Craig; Schroeder, Grant; Fieldhouse, Ben; Brown, Carl E; van Aggelen, Graham; Shang, Dayue

2018-05-01

The present study investigated oil dispersant toxicity to fish species typical of the cooler regions of Canada, together with less well-documented issues pertaining to oil dispersant monitoring. The oil dispersant toxicity of Corexit EC9500A was assessed for the freshwater fish species rainbow trout and the seawater species coho, chinook, and chum, with a final median lethal concentration (LC50) acute lethality range between 35.3 and 59.8 mg/L. The LC50 range was calculated using confirmed 0-h dispersant concentrations that were justified by fish mortality within the first 24 h of exposure and by variability of the dispersant indicator dioctyl sulfosuccinate (DOSS) used to monitor concentrations at later time points. To investigate DOSS as an oil dispersant indicator in the environment, microcosm systems were prepared containing Corexit EC9500A, Finasol OSR52, Slickgone NS, and Slickgone EW dispersants together with diluted bitumen. The DOSS indicator recovery was found to be stable for up to 13 d at 5 °C, 8 d at 10 °C, but significantly less than 8 d at ≥15 °C. After 3 d at temperatures ≥15 °C, the DOSS indicator recovery became less accurate and was dependent on multiple environmental factors including temperature, microbial activity, and aeration, with potential for loss of solvents and stabilizers. A final assessment determined DOSS to be a discrepant indicator for long-term monitoring of oil dispersant in seawater. Environ Toxicol Chem 2018;37:1309-1319. © 2018 SETAC. © 2018 SETAC.

Oil biodegradation: Interactions of artificial marine snow, clay particles, oil and Corexit.

PubMed

Rahsepar, Shokouh; Langenhoff, Alette A M; Smit, Martijn P J; van Eenennaam, Justine S; Murk, Albertinka J; Rijnaarts, Huub H M

2017-12-15

During the Deepwater Horizon (DwH) oil spill, interactions between oil, clay particles and marine snow lead to the formation of aggregates. Interactions between these components play an important, but yet not well understood, role in biodegradation of oil in the ocean water. The aim of this study is to explore the effect of these interactions on biodegradation of oil in the water. Laboratory experiments were performed, analyzing respiration and n-alkane and BTEX biodegradation in multiple conditions containing Corexit, alginate particles as marine snow, and kaolin clay. Two oil degrading bacterial pure cultures were added, Pseudomonas putida F1 and Rhodococcus qingshengii TUHH-12. Results show that the presence of alginate particles enhances oil biodegradation. The presence of Corexit alone or in combination with alginate particles and/or kaolin clay, hampers oil biodegradation. Kaolin clay and Corexit have a synergistic effect in increasing BTEX concentrations in the water and cause delay in oil biodegradation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dispersion of Louisiana crude oil in salt water environment by Corexit 9500A in the presence of natural coastal materials

NASA Astrophysics Data System (ADS)

Tansel, Berrin; Lee, Mengshan; Berbakov, Jillian; Tansel, Derya Z.; Koklonis, Urpiana

2014-04-01

Effectiveness of Corexit 9500A for dispersing Louisiana crude oil was evaluated in salt water solutions containing natural materials in relation to salinity and dispersant-to-oil ratio (DOR). Experimental results showed that both salinity and DOR had significant effects on dispersion of Louisiana crude oil in the presence of different natural materials. The natural materials added to the salt water solutions included sea sand (South Beach, Miami, Florida), red mangrove leaves (Rhizophora mangle), seaweed (Sargassum natans), and sea grass (Halodule wrightii). Dispersant effectiveness (amount of oil dispersed into the water) was reduced significantly with increasing salinity with the minimum effectiveness observed in the salinity range between 30 and 50 ppt in all aqueous samples containing natural materials. When significant amounts of floating oil were present, the partially submerged natural materials enhanced the transfer of oil into the water column, which improved the dispersion effectiveness. However, dispersant effectiveness was significantly reduced when the amount of floating oil was relatively small and could not be released back to the water column. Surface tension may not be an adequate parameter for monitoring the effectiveness of dispersants in salt water environment. When distilled water was used (i.e., zero salinity), surface tension was significantly reduced with increasing dispersant concentration. However, there was no clear trend in the surface tension of the salt water solutions (17-51 ppt) containing crude oil and natural materials with increasing dispersant concentration.

Depletion and biodegradation of hydrocarbons in dispersions and emulsions of the Macondo 252 oil generated in an oil-on-seawater mesocosm flume basin.

PubMed

Brakstad, Odd G; Daling, Per S; Faksness, Liv-G; Almås, Inger K; Vang, Siv-H; Syslak, Line; Leirvik, Frode

2014-07-15

Physically and chemically (Corexit 9500) generated Macondo 252 oil dispersions, or emulsions (no Corexit), were prepared in an oil-on-seawater mesocosm flume basin at 30-32 °C, and studies of oil compound depletion performed for up to 15 days. The use of Corexit 9500 resulted in smaller median droplet size than in a physically generated dispersion. Rapid evaporation of low boiling point oil compounds (C⩽15) appeared in all the experiments. Biodegradation appeared to be an important depletion process for compounds with higher boiling points in the dispersions, but was negligible in the surface emulsions. While n-alkane biodegradation was faster in chemically than in physically dispersed oil no such differences were determined for 3- and 4-ring PAH compounds. In the oil dispersions prepared by Corexit 9500, increased cell concentrations, reduction in bacterial diversity, and a temporary abundance of bacteria containing an alkB gene were associated with oil biodegradation. Copyright © 2014 Elsevier Ltd. All rights reserved.

The physiological effects of oil, dispersant and dispersed oil on the bay mussel, Mytilus trossulus, in Arctic/Subarctic conditions.

PubMed

Counihan, Katrina L

2018-06-01

Increasing oil development around Alaska and other Arctic regions elevates the risk for another oil spill. Dispersants are used to mitigate the impact of an oil spill by accelerating natural degradation processes, but the reduced hydrophobicity of dispersed oil may increase its bioavailability to marine organisms. There is limited research on the effect of dispersed oil on cold water species and ecosystems. Therefore, spiked exposure tests were conducted with bay mussels (Mytilus trossulus) in seawater with non-dispersed oil, Corexit 9500 and oil dispersed with different concentrations of Corexit 9500. After three weeks of exposure, acute and chronic physiological impacts were determined. The majority of physiological responses occurred during the first seven days of exposure, with mussels exhibiting significant cytochrome P450 activity, superoxide dismutase activity and heat shock protein levels. Mussels exposed to non-dispersed oil also experienced immune suppression, reduced transcription and higher levels of mortality. After 21 days, mussels in all treatments exhibited evidence of genetic damage, tissue loss and a continued stress response. Bay mussels are useful as indicators of ecosystem health and recovery, and this study was an important step in understanding how non-dispersed oil, dispersant and dispersed oil affect the physiology of this sentinel species in Arctic/subarctic conditions. Copyright © 2018 Elsevier B.V. All rights reserved.

Biodegradation of dispersed Macondo oil in seawater at low temperature and different oil droplet sizes.

PubMed

Brakstad, Odd G; Nordtug, Trond; Throne-Holst, Mimmi

2015-04-15

During the Deepwater Horizon (DWH) accident in 2010 a dispersant (Corexit 9500) was applied at the wellhead to disperse the Macondo oil and reduce the formation of surface slicks. A subsurface plume of small oil droplets was generated near the leaking well at 900-1300 m depth. A novel laboratory system was established to investigate biodegradation of small droplet oil dispersions (10 μm or 30 μm droplet sizes) of the Macondo oil premixed with Corexit 9500, using coastal Norwegian seawater at a temperature similar to the DWH plume (4-5°C). Biotransformation of volatile and semivolatile hydrocarbons and oil compound groups was generally faster in the 10 μm than in the 30 μm dispersions, showing the importance of oil droplet size for biodegradation. These data therefore indicated that dispersant treatment to reduce the oil droplet size may increase the biodegradation rates of oil compounds in the deepwater oil droplets. Copyright © 2015 Elsevier Ltd. All rights reserved.

Hydrocarbon-Degrading Bacteria Exhibit a Species-Specific Response to Dispersed Oil while Moderating Ecotoxicity

PubMed Central

Overholt, Will A.; Marks, Kala P.; Romero, Isabel C.; Hollander, David J.; Snell, Terry W.

2015-01-01

The Deepwater Horizon blowout in April 2010 represented the largest accidental marine oil spill and the largest release of chemical dispersants into the environment to date. While dispersant application may provide numerous benefits to oil spill response efforts, the impacts of dispersants and potential synergistic effects with crude oil on individual hydrocarbon-degrading bacteria are poorly understood. In this study, two environmentally relevant species of hydrocarbon-degrading bacteria were utilized to quantify the response to Macondo crude oil and Corexit 9500A-dispersed oil in terms of bacterial growth and oil degradation potential. In addition, specific hydrocarbon compounds were quantified in the dissolved phase of the medium and linked to ecotoxicity using a U.S. Environmental Protection Agency (EPA)-approved rotifer assay. Bacterial treatment significantly and drastically reduced the toxicity associated with dispersed oil (increasing the 50% lethal concentration [LC50] by 215%). The growth and crude oil degradation potential of Acinetobacter were inhibited by Corexit by 34% and 40%, respectively; conversely, Corexit significantly enhanced the growth of Alcanivorax by 10% relative to that in undispersed oil. Furthermore, both bacterial strains were shown to grow with Corexit as the sole carbon and energy source. Hydrocarbon-degrading bacterial species demonstrate a unique response to dispersed oil compared to their response to crude oil, with potentially opposing effects on toxicity. While some species have the potential to enhance the toxicity of crude oil by producing biosurfactants, the same bacteria may reduce the toxicity associated with dispersed oil through degradation or sequestration. PMID:26546426

Oil and oil dispersant do not cause synergistic toxicity to fish embryos.

PubMed

Adams, Julie; Sweezey, Michael; Hodson, Peter V

2014-01-01

Atlantic herring (Clupea harengus) embryos were exposed to water accommodated fractions (WAFs; oil dissolved in water) and chemically enhanced water accommodated fractions (CEWAFs; oil dispersed in water with Corexit 9500A) of Medium South American (MESA) crude oil. The CEWAF was approximately 100-fold more toxic than WAF based on nominal loadings of test solutions (% v/v). In contrast, the ratio of WAF and CEWAF toxicity expressed as measured oil concentrations approximated 1.0, indicating that the higher toxicity of CEWAFs was caused by an increase in exposure to hydrocarbons with chemical dispersion. In a second experiment, the chronic toxicity of Corexit 9500A and chemically dispersed heavy fuel oil 7102 (HFO 7102) to rainbow trout (Oncorhynchus mykiss) embryos was compared to chemically dispersed Nujol, a nontoxic mineral oil. Dispersant alone was toxic, but caused different signs of toxicity than HFO 7102. Nujol at a dispersant-to-oil ratio of 1:20 was nontoxic, suggesting that dispersant was sequestered by oil and not present at toxic concentrations. In contrast, the same nominal loadings of dispersed HFO 7102 caused concentration-dependent increases in toxicity. Both experiments suggest that chemically dispersed oil was more toxic to fish embryos than solutions created by mechanical mixing due to the increased exposure of fish to petroleum hydrocarbons and not to changes in hydrocarbon toxicity. The Nujol control discriminated between the toxicity of oil and chemical dispersant and would be a practical addition to programs of dispersant testing.

Chemical dispersion of oil with mineral fines in a low temperature environment.

PubMed

Wang, Weizhi; Zheng, Ying; Lee, Kenneth

2013-07-15

The increasing risks of potential oil spills in the arctic regions, which are characterized by low temperatures, are a big challenge. The traditional dispersant method has shown limited effectiveness in oil cleanup. This work studied the role of mineral fines in the formation of oil-mineral aggregates (OMAs) at low temperature (0-4 °C) environment. The loading amount of minerals and dispersant with different dispersant and oil types were investigated under a full factorial design. The shapes and sizes of OMAs were analyzed. Results showed that the behavior of OMA formation differs when dispersant and mineral fines are used individually or together. Both the experimental and microscopic results also showed the existence of optimal dispersant to oil ratios and mineral to oil ratios. In general, poor oil removal performance was observed for more viscous oil. Corexit 9500 performed better than Corexit 9527 with various oils, in terms of oil dispersion and OMA formation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effects of Salinity on Oil Spill Dispersant Toxicity in Estuarine Organisms

NASA Astrophysics Data System (ADS)

Eckmann, C. A.

2016-02-01

Chemical dispersants can be a useful tool to mitigate oil spills, but the potential risks to sensitive estuarine species should be carefully considered. To improve the decision making process, more information is needed regarding the effects of oil spill dispersants on the health of coastal ecosystems under variable environmental conditions such as salinity. The two oil dispersants used in this study were Corexit ® 9500 and Finasol ® OSR 52. Corexit ® 9500 was the primary dispersant used during the 2010 Deepwater Horizon oil spill event, while Finasol® OSR 52 is another dispersant approved for oil spill response in the U.S., yet considerably less is known regarding its toxicity to estuarine species. The grass shrimp, Palaemonetes pugio, was used as a model estuarine species. It is a euryhaline species that tolerates salinities from brackish to full strength seawater. Adult and larval life stages were tested with each dispersant at three salinities, 5ppt, 20ppt, and 30ppt. Median acute lethal toxicity thresholds were calculated. Lipid peroxidation assays were conducted on surviving shrimp to investigate sublethal effects. The toxicity of both dispersants was significantly influenced by salinity, with greatest toxicity observed at the lowest salinity tested. Larval shrimp were significantly more sensitive than adult shrimp to both dispersants, and both life stages were significantly more sensitive to Finasol than to Corexit. Furthermore, significant sublethal effects were seen at higher concentrations of both dispersants compared to the control. These data will enable environmental managers to make informed decisions regarding dispersant use in future oil spills.

Effects of Salinity on Oil Spill Dispersant Toxicity in Estuarine Organisms

NASA Astrophysics Data System (ADS)

Eckmann, C. A.

2015-12-01

Chemical dispersants can be a useful tool to mitigate oil spills, but the potential risks to sensitive estuarine species should be carefully considered. To improve the decision making process, more information is needed regarding the effects of oil spill dispersants on the health of coastal ecosystems under variable environmental conditions such as salinity. The two oil dispersants used in this study were Corexit ® 9500 and Finasol ® OSR 52. Corexit ® 9500 was the primary dispersant used during the 2010 Deepwater Horizon oil spill event, while Finasol® OSR 52 is another dispersant approved for oil spill response in the U.S., yet considerably less is known regarding its toxicity to estuarine species. The grass shrimp, Palaemonetes pugio, was used as a model estuarine species. It is a euryhaline species that tolerates salinities from brackish to full strength seawater. Adult and larval life stages were tested with each dispersant at three salinities, 5ppt, 20ppt, and 30ppt. Median acute lethal toxicity thresholds were calculated. Lipid peroxidation assays were conducted on surviving shrimp to investigate sublethal effects. The toxicity of both dispersants was significantly influenced by salinity, with greatest toxicity observed at the lowest salinity tested. Larval shrimp were significantly more sensitive than adult shrimp to both dispersants, and both life stages were significantly more sensitive to Finasol than to Corexit. Furthermore, significant sublethal effects were seen at higher concentrations of both dispersants compared to the control. These data will enable environmental managers to make informed decisions regarding dispersant use in future oil spills.

Carcinogenic Effects of Oil Dispersants: a KEGG Pathway-based RNA-seq Study of Human Airway Epithelial Cells

PubMed Central

Liu, Yao-Zhong; Zhang, Lei; Roy-Engel, Astrid M; Saito, Shigeki; Lasky, Joseph A; Wang, Guangdi; Wang, He

2016-01-01

The health impacts of the BP oil spill are yet to be further revealed as the toxicological effects of oil products and dispersants on human respiratory system may be latent and complex, and hence difficult to study and follow up. Here we performed RNA-seq analyses of a system of human airway epithelial cells treated with the BP crude oil and/or dispersants Corexit 9500 and Corexit 9527 that were used to help break up the oil spill. Based on the RNA-seq data, we then systemically analyzed the transcriptomic perturbations of the cells at the KEGG pathway level using two pathway-based analysis tools, GAGE (generally applicable gene set enrichment) and GSNCA (Gene Sets Net Correlations Analysis). Our results suggested a pattern of change towards carcinogenesis for the treated cells marked by upregulation of ribosomal biosynthesis (hsa03008) (p = 1.97e-13), protein processing (hsa04141) (p = 4.09e-7), Wnt signaling (hsa04310) (p = 6.76e-3), neurotrophin signaling (hsa04722) (p = 7.73e-3) and insulin signaling (hsa04910) (p = 1.16e-2) pathways under the dispersant Corexit 9527 treatment, as identified by GAGE analysis. Furthermore, through GSNCA analysis, we identified gene co-expression changes for several KEGG cancer pathways, including small cell lung cancer pathway (hsa05222, p = 9.99e-5), under various treatments of oil/dispersant, especially the mixture of oil and Corexit 9527. Overall, our results suggested carcinogenic effects of dispersants (in particular Corexit 9527) and their mixtures with the BP crude oil, and provided further support for more stringent safety precautions and regulations for operations involving long-term respiratory exposure to oil and dispersants. PMID:27866042

Mechanistic investigation into sunlight-facilitated photodegradation of pyrene in seawater with oil dispersants.

PubMed

Fu, Jie; Gong, Yanyan; Cai, Zhengqing; O'Reilly, S E; Zhao, Dongye

2017-01-30

This study investigated the effects of 3 model oil dispersants (Corexit EC9500A, Corexit EC9527A and SPC 1000) on photodegradation of pyrene under simulated sunlight. Both Corexit dispersants enhanced photodegradation of pyrene, while SPC1000 slightly inhibited the reaction. Span 80 and Tween 85 were the key ingredients causing the effects, though the underlying mechanisms differed. Span 80 enriches pyrene in the upper layer of water column, whereas Tween 85 induces a photosensitization process. Two reactive oxygen species, 1 O 2 and O 2 - , were found responsible for pyrene photodegradation, though the presence of EC9500A suppressed the 1 O 2 pathway. In terms of photodegradation products, EC9500A enhanced generation of polyaromatic intermediates, i.e., phenaleno[1,9-cd][1,2]dioxine, 1-hydroxypyrene, and 1,8-pyrenequinone, but did not alter the classical photodegradation pathway. The Corexit dispersants were more prone to photochemical decomposition, with multiple by-products detected. The information aids in our understanding of the effects of dispersants on photochemical weathering of oil compositions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Dispersion, sorption and photodegradation of petroleum hydrocarbons in dispersant-seawater-sediment systems.

PubMed

Zhao, Xiao; Liu, Wen; Fu, Jie; Cai, Zhengqing; O'Reilly, S E; Zhao, Dongye

2016-08-15

This work examined effects of model oil dispersants on dispersion, sorption and photodegradation of petroleum hydrocarbons in simulated marine systems. Three dispersants (Corexit 9500A, Corexit 9527A and SPC 1000) were used to prepare dispersed water accommodated oil (DWAO). While higher doses of dispersants dispersed more n-alkanes and PAHs, Corexit 9500A preferentially dispersed C11-C20 n-alkanes, whereas Corexit 9527A was more favorable for smaller alkanes (C10-C16), and SPC 1000 for C12-C28 n-alkanes. Sorption of petroleum hydrocarbons on sediment was proportional to TPH types/fractions in the DWAOs. Addition of 18mg/L of Corexit 9500A increased sediment uptake of 2-3 ring PAHs, while higher dispersant doses reduced the uptake, due to micelle-enhanced solubilization effects. Both dispersed n-alkanes and PAHs were susceptible to photodegradation under simulated sunlight. For PAHs, both photodegradation and photo-facilitated alkylation were concurrently taking place. The information can facilitate sounder assessment of fate and distribution of dispersed oil hydrocarbons in marine systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

Toxicity of oil and dispersant on the deep water gorgonian octocoral Swiftia exserta, with implications for the effects of the Deepwater Horizon oil spill.

PubMed

Frometa, Janessy; DeLorenzo, Marie E; Pisarski, Emily C; Etnoyer, Peter J

2017-09-15

Benthic surveys of mesophotic reefs in the Gulf of Mexico post Deepwater Horizon (DWH) showed that Swiftia exserta octocorals exhibited significantly more injury than in years before the spill. To determine the vulnerability of S. exserta to oil and dispersants, 96h toxicity assays of surrogate DWH oil water-accommodated fractions (WAF), Corexit® 9500 dispersant, and the combination of both (CEWAF) were conducted in the laboratory. Fragment mortality occurred within 48h for some fragments in the dispersant-alone and oil-dispersant treatments, while the WAF group remained relatively unaffected. The 96h LC 50 values were 70.27mg/L for Corexit-alone and 41.04mg/L for Corexit in CEWAF. This study provides new information on octocoral sensitivity to toxins, and indicates that combinations of oil and dispersants are more toxic to octocorals than exposure to oil alone. These results have important implications for the assessment of effects of the DWH spill on deep-water organisms. Copyright © 2017 Elsevier Ltd. All rights reserved.

Embryotoxicity of Corexit 9500 in mallard ducks (Anas platyrhynchos).

PubMed

Wooten, Kimberly J; Finch, Bryson E; Smith, Philip N

2012-04-01

Embryotoxicity of the oil dispersant Corexit 9500 was examined using fertilized mallard duck eggs. Corexit 9500 was topically applied below the air cell to eggs in volumes ranging from 0 to 100 μL on day 3 of incubation. The highest incidence of mortality occurred at developmental stage 4, one day post-Corexit 9500 application. Hatching success was significantly decreased among eggs treated with ≥ 20 μL of Corexit 9500 as compared to controls (P ≤ 0.047). No egg treated with ≥ 40 μL successfully hatched. The application volume resulting in 50% mortality (corrected for control survival) was determined to be 15.5 μL. Developmental stage at embryo death was also significantly decreased compared to controls in eggs exposed to 40 μL (P = 0.0042) and above.

Effects of a chemical dispersant and crude oil on breeding ducks

USGS Publications Warehouse

Albers, P.H.; Gay, M.L.

1982-01-01

Effects of chemically dispersed crude oil on mallard reproduction. Incubating female mallards were exposed to a water source treated with either Prudhoe Bay crude oil, Corexit 9527, or a combination of oil and dispersant during the first 10 da of development. Used thermocouple probes to monitor incubation temperature. Measured hatching success, incubation temperature, and survival of ducklings to 1 wk of age.

Effects of oil dispersants on photodegradation of parent and alkylated anthracene in seawater.

PubMed

Cai, Zhengqing; Liu, Wen; Fu, Jie; O'Reilly, S E; Zhao, Dongye

2017-10-01

This study investigated effects of three model oil dispersants on photodegradation of two model PAHs (anthracene and 9,10-dimethyanthracene (9,10-DMA)) under simulated sunlight. All three dispersants, i.e. Corexit EC9500A, Corexit EC9527A and SPC 1000, promoted the photolysis rate of 9,10-DMA, following the order of Corexit EC9500A > Corexit EC9527A > SPC 1000. The photodegradation rate was well interpreted by a two-stage, first-order kinetic law with a faster initial photolysis rate in the presence of the dispersants. Span 80, Tween 85 and kerosene were found as the key dispersant components, of which Span 80 and Tween 85 promoted the photodegradation by boosting absorbance of solar irradiation while kerosene by dispersing more PAHs in the upper layer of the water column. Dissolved oxygen (DO) inhibited photolysis of anthracene regardless of dispersant resulting from quenching the excited states of the PAH, while DO facilitated photolysis of 9,10-DMA due to the formation singlet oxygen ( 1 O 2 ) radicals in the presence of oil dispersants. The other ROS, i.e. •O 2 - and •OH, played a negligible role on the photodegradation of anthracene and 9,10-DMA. Fluorescence analysis showed that more anthracene was associated with dispersant than 9,10-DMA, which favored the direct transfer of energy to anthracene, while energy is more likely transferred to oxygen to form 1 O 2 in the case of 9,10-DMA. Direct photolysis dominated the photodegradation of anthracene and 9,10-DMA. Both direct ionization of anthracene and the electron transfer from excited 9,10-DMA to oxygen can lead to formation of the corresponding PAH radical cations. Overall, the oil dispersants accelerated the photolysis rates of the PAHs without altering the degradation pathway. The findings are useful for understanding photochemical weathering of dispersed oil components in the environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of initial oil concentration and dispersant on crude oil biodegradation in contaminated seawater.

PubMed

Zahed, Mohammad Ali; Aziz, Hamidi Abdul; Isa, Mohamed Hasnain; Mohajeri, Leila

2010-04-01

The effects of initial oil concentration and the Corexit 9500 dispersant on the rate of bioremediation of petroleum hydrocarbons were investigated with a series of ex-situ seawater samples. With initial oil concentrations of 100, 500, 1,000 and 2,000 mg/L, removal of total petroleum hydrocarbons (TPHs) with dispersant were 67.3%, 62.5%, 56.5% and 44.7%, respectively, and were 64.2%, 55.7%, 48.8% and 37.6% without dispersant. The results clearly indicate that the presence of dispersant enhanced crude oil biodegradation. Lower concentrations of crude oil demonstrated more efficient hydrocarbon removal. Based on these findings, bioremediation is not recommended for crude oil concentrations of 2,000 mg/L or higher.

Corexit-EC9527A Disrupts Retinol Signaling and Neuronal Differentiation in P19 Embryonal Pluripotent Cells

DOE PAGES

Chen, Yanling; Reese, David H.; Kelly, Gregory M.

2016-09-29

Corexit-EC9500A and Corexit-EC9527A are two chemical dispersants that have been used to remediate the impact of the 2010 Deepwater Horizon oil spill. Both dispersants are composed primarily of organic solvents and surfactants and act by emulsifying the crude oil to facilitate biodegradation. The potential adverse effect of the Corexit chemicals on mammalian embryonic development remains largely unknown. Retinol (vitamin A) signaling, mediated by all-trans retinoic acid (RA), is essential for neural tube formation and the development of many organs in the embryo. The physiological levels of RA in cells and tissues are maintained by the retinol signaling pathway (RSP), whichmore » controls the biosynthesis of RA from dietary retinol and the catabolism of RA to polar metabolites for removal. RA is a potent activating ligand for the RAR/RXR nuclear receptors. Through RA and the receptors, the RSP modulates the expression of many developmental genes; interference with the RSP is potentially teratogenic. In this study the mouse P19 embryonal pluripotent cell, which contains a functional RSP, was used to evaluate the effects of the Corexit dispersants on retinol signaling and associated neuronal differentiation. The results showed that Corexit-EC9500A was more cytotoxic than Corexit-EC9527A to P19 cells. At non-cytotoxic doses, Corexit-EC9527A inhibited retinol-induced expression of the Hoxa1 gene, which encodes a transcription factor for the regulation of body patterning in the embryo. Such inhibition was seen in the retinol- and retinal- induced, but not RA-induced, Hoxa1 up-regulation, indicating that the Corexit chemicals primarily inhibit RA biosynthesis from retinal. In addition, Corexit-EC9527A suppressed retinol-induced P19 cell differentiation into neuronal cells, indicating potential neurotoxic effect of the chemicals under the tested conditions. In conclusion, the surfactant ingredient, dioctyl sodium sulfosuccinate (DOSS), may be a major contributor to the

Corexit-EC9527A Disrupts Retinol Signaling and Neuronal Differentiation in P19 Embryonal Pluripotent Cells

PubMed Central

Chen, Yanling; Reese, David H.

2016-01-01

Corexit-EC9500A and Corexit-EC9527A are two chemical dispersants that have been used to remediate the impact of the 2010 Deepwater Horizon oil spill. Both dispersants are composed primarily of organic solvents and surfactants and act by emulsifying the crude oil to facilitate biodegradation. The potential adverse effect of the Corexit chemicals on mammalian embryonic development remains largely unknown. Retinol (vitamin A) signaling, mediated by all-trans retinoic acid (RA), is essential for neural tube formation and the development of many organs in the embryo. The physiological levels of RA in cells and tissues are maintained by the retinol signaling pathway (RSP), which controls the biosynthesis of RA from dietary retinol and the catabolism of RA to polar metabolites for removal. RA is a potent activating ligand for the RAR/RXR nuclear receptors. Through RA and the receptors, the RSP modulates the expression of many developmental genes; interference with the RSP is potentially teratogenic. In this study the mouse P19 embryonal pluripotent cell, which contains a functional RSP, was used to evaluate the effects of the Corexit dispersants on retinol signaling and associated neuronal differentiation. The results showed that Corexit-EC9500A was more cytotoxic than Corexit-EC9527A to P19 cells. At non-cytotoxic doses, Corexit-EC9527A inhibited retinol-induced expression of the Hoxa1 gene, which encodes a transcription factor for the regulation of body patterning in the embryo. Such inhibition was seen in the retinol- and retinal- induced, but not RA-induced, Hoxa1 up-regulation, indicating that the Corexit chemicals primarily inhibit RA biosynthesis from retinal. In addition, Corexit-EC9527A suppressed retinol-induced P19 cell differentiation into neuronal cells, indicating potential neurotoxic effect of the chemicals under the tested conditions. The surfactant ingredient, dioctyl sodium sulfosuccinate (DOSS), may be a major contributor to the observed effect of

Corexit-EC9527A Disrupts Retinol Signaling and Neuronal Differentiation in P19 Embryonal Pluripotent Cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Yanling; Reese, David H.; Kelly, Gregory M.

Corexit-EC9500A and Corexit-EC9527A are two chemical dispersants that have been used to remediate the impact of the 2010 Deepwater Horizon oil spill. Both dispersants are composed primarily of organic solvents and surfactants and act by emulsifying the crude oil to facilitate biodegradation. The potential adverse effect of the Corexit chemicals on mammalian embryonic development remains largely unknown. Retinol (vitamin A) signaling, mediated by all-trans retinoic acid (RA), is essential for neural tube formation and the development of many organs in the embryo. The physiological levels of RA in cells and tissues are maintained by the retinol signaling pathway (RSP), whichmore » controls the biosynthesis of RA from dietary retinol and the catabolism of RA to polar metabolites for removal. RA is a potent activating ligand for the RAR/RXR nuclear receptors. Through RA and the receptors, the RSP modulates the expression of many developmental genes; interference with the RSP is potentially teratogenic. In this study the mouse P19 embryonal pluripotent cell, which contains a functional RSP, was used to evaluate the effects of the Corexit dispersants on retinol signaling and associated neuronal differentiation. The results showed that Corexit-EC9500A was more cytotoxic than Corexit-EC9527A to P19 cells. At non-cytotoxic doses, Corexit-EC9527A inhibited retinol-induced expression of the Hoxa1 gene, which encodes a transcription factor for the regulation of body patterning in the embryo. Such inhibition was seen in the retinol- and retinal- induced, but not RA-induced, Hoxa1 up-regulation, indicating that the Corexit chemicals primarily inhibit RA biosynthesis from retinal. In addition, Corexit-EC9527A suppressed retinol-induced P19 cell differentiation into neuronal cells, indicating potential neurotoxic effect of the chemicals under the tested conditions. In conclusion, the surfactant ingredient, dioctyl sodium sulfosuccinate (DOSS), may be a major contributor to the

Biodegradation of dispersed oil in Arctic seawater at -1°C.

PubMed

McFarlin, Kelly M; Prince, Roger C; Perkins, Robert; Leigh, Mary Beth

2014-01-01

As offshore oil and gas exploration expands in the Arctic, it is important to expand the scientific understanding of arctic ecology and environmental impact to mitigate operational risks. Understanding the fate of oil in arctic seawater is a key factor for consideration. Here we report the chemical loss due to the biodegradation of Alaska North Slope (ANS) crude oil that would occur in the water column following the successful dispersion of a surface oil slick. Primary biodegradation and mineralization were measured in mesocosms containing Arctic seawater collected from the Chukchi Sea, Alaska, incubated at -1°C. Indigenous microorganisms degraded both fresh and weathered oil, in both the presence and absence of Corexit 9500, with oil losses ranging from 46-61% and up to 11% mineralization over 60 days. When tested alone, 14% of 50 ppm Corexit 9500 was mineralized within 60 days. Our study reveals that microorganisms indigenous to Arctic seawater are capable of performing extensive biodegradation of chemically and physically dispersed oil at an environmentally relevant temperature (-1°C) without any additional nutrients.

Biodegradation of Dispersed Oil in Arctic Seawater at -1°C

PubMed Central

McFarlin, Kelly M.; Prince, Roger C.; Perkins, Robert; Leigh, Mary Beth

2014-01-01

As offshore oil and gas exploration expands in the Arctic, it is important to expand the scientific understanding of arctic ecology and environmental impact to mitigate operational risks. Understanding the fate of oil in arctic seawater is a key factor for consideration. Here we report the chemical loss due to the biodegradation of Alaska North Slope (ANS) crude oil that would occur in the water column following the successful dispersion of a surface oil slick. Primary biodegradation and mineralization were measured in mesocosms containing Arctic seawater collected from the Chukchi Sea, Alaska, incubated at −1°C. Indigenous microorganisms degraded both fresh and weathered oil, in both the presence and absence of Corexit 9500, with oil losses ranging from 46−61% and up to 11% mineralization over 60 days. When tested alone, 14% of 50 ppm Corexit 9500 was mineralized within 60 days. Our study reveals that microorganisms indigenous to Arctic seawater are capable of performing extensive biodegradation of chemically and physically dispersed oil at an environmentally relevant temperature (−1°C) without any additional nutrients. PMID:24416211

Improving oiled shoreline cleanup with COREXIT 9580

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fiocco, R.J.; Lessard, R.R.; Canevari, G.P.

1996-08-01

The cleanup of oiled shorelines has generally been by mechanical, labor-intensive means. The use of a chemical shoreline cleaner to assist in water-flushing oil from the surfaces can result in more complete and more rapid cleaning. Not only is the cleaning process more efficient, but it can also be less environmentally damaging since there is potentially much less human intrusion and stress on the biological community. This paper describes research and applications of COREXIT 9580 shoreline cleaner for treatment of oiled shorelines, including four recent applications in Puerto Rico, Bermuda, Texas and Nova Scotia. Research work on shoreline vegetation, suchmore » as mangroves, has also demonstrated the potential use of this product to save and restore oiled vegetation.« less

Corexit 9500 inactivates two enveloped viruses of aquatic animals but enhances the infectivity of a nonenveloped fish virus.

PubMed

Pham, P H; Huang, Y J; Chen, C; Bols, N C

2014-02-01

The effects of Corexit 9500, a dispersant used to clean up oil spills, on invertebrates, lower vertebrates, birds, and human health have been examined, but there is a significant lack of study of the effect of this dispersant on aquatic viruses. In this study, the effects of Corexit 9500 on four aquatic viruses of differing structural composition were examined. Corexit 9500 reduced the titer of the enveloped viral hemorrhagic septicemia virus (VHSV) at all concentrations (10% to 0.001%) examined. The titer of frog virus 3 (FV3), a virus with both enveloped and nonenveloped virions, was reduced only at the high Corexit 9500 concentrations (10% to 0.1%). Corexit 9500 was unable to reduce the titer of nonenveloped infectious pancreatic necrosis virus (IPNV) but enhanced the titer of chum salmon reovirus (CSV) by 2 to 4 logs. With the ability to inactivate enveloped viruses and possibly enhance some nonenveloped viruses, Corexit 9500 has the potential to alter the aquatic virosphere.

Effect of Two Oil Dispersants on Larval Grass Shrimp (Palaemonetes pugio) Development.

NASA Astrophysics Data System (ADS)

Betancourt, P.; Key, P. B.; Chung, K. W.; DeLorenzo, M. E.

2015-12-01

The study focused on the effects that two oil dispersants, Corexit® EC9500A and Finasol® OSR52, have on the development of larval grass shrimp, (Palaemonetes pugio). The hypothesis was that Finasol would have a greater effect on larval grass shrimp development than Corexit. The experiment was conducted using 300 grass shrimp larvae that were 24 hours old. Each larva was exposed individually. In total, five sub-lethal concentrations were tested for each dispersant (control, 1.25, 2.50, 5.0,10.0 mg/L). The larvae were exposed for five days then transferred to clean seawater until metamorphosis into the juvenile stage. Key data measurements recorded included number of days to become juveniles, number of instars, length, dry weight, and mortality. Data from exposed shrimp was compared to the results of the control for each dispersant concentration. Corexit and Finasol exposure treatments of 5 mg/L and 10 mg/L showed significantly higher values for number of days and number of instars to reach juvenile status than values obtained from unexposed, control shrimp. Overall, mortality was higher in the Finasol treatments but the two dispersants did not respond significantly different from one another. Future studies are needed to determine the long term effects of dispersant exposure on all grass shrimp life stages and how any dispersant exposure impacts grass shrimp populations. Grass shrimp serve as excellent toxicity indicators of estuaries, and further studies will help to develop better oil spill mitigation techniques.

Chemical dispersants: Oil biodegradation friend or foe?

PubMed

Rahsepar, Shokouh; Smit, Martijn P J; Murk, Albertinka J; Rijnaarts, Huub H M; Langenhoff, Alette A M

2016-07-15

Chemical dispersants were used in response to the Deepwater Horizon oil spill in the Gulf of Mexico, both at the sea surface and the wellhead. Their effect on oil biodegradation is unclear, as studies showed both inhibition and enhancement. This study addresses the effect of Corexit on oil biodegradation by alkane and/or aromatic degrading bacterial culture in artificial seawater at different dispersant to oil ratios (DORs). Our results show that dispersant addition did not enhance oil biodegradation. At DOR 1:20, biodegradation was inhibited, especially when only the alkane degrading culture was present. With a combination of cultures, this inhibition was overcome after 10days. This indicates that initial inhibition of oil biodegradation can be overcome when different bacteria are present in the environment. We conclude that the observed inhibition is related to the enhanced dissolution of aromatic compounds into the water, inhibiting the alkane degrading bacteria. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effects of Crude Oil, Dispersant, and Oil-Dispersant Mixtures on Human Fecal Microbiota in an In Vitro Culture System

PubMed Central

Kim, Jong Nam; Kim, Bong-Soo; Kim, Seong-Jae; Cerniglia, Carl E.

2012-01-01

ABSTRACT The Deepwater Horizon oil spill of 2010 raised concerns that dispersant and dispersed oil, as well as crude oil itself, could contaminate shellfish and seafood habitats with hazardous residues that had potential implications for human health and the ecosystem. However, little is known about the effects of crude oil and dispersant on the human fecal microbiota. The aim of this research was to evaluate the potential effects of Deepwater Horizon crude oil, Corexit 9500 dispersant, and their combination on human fecal microbial communities, using an in vitro culture test system. Fecal specimens from healthy adult volunteers were made into suspensions, which were then treated with oil, dispersant, or oil-dispersant mixtures under anaerobic conditions in an in vitro culture test system. Perturbations of the microbial community, compared to untreated control cultures, were assessed using denaturing gradient gel electrophoresis (DGGE), real-time PCR, and pyrosequencing methods. DGGE and pyrosequencing analysis showed that oil-dispersant mixtures reduced the diversity of fecal microbiota from all individuals. Real-time PCR results indicated that the copy numbers of 16S rRNA genes in cultures treated with dispersed oil or oil alone were significantly lower than those in control incubations. The abundance of the Bacteroidetes decreased in crude oil-treated and dispersed-oil-treated cultures, while the Proteobacteria increased in cultures treated with dispersed oil. In conclusion, the human fecal microbiota was affected differently by oil and dispersed oil, and the influence of dispersed oil was significantly greater than that of either oil or dispersant alone compared to control cultures. PMID:23093387

Generation of shrimp waste-based dispersant for oil spill response.

PubMed

Zhang, Kedong; Zhang, Baiyu; Song, Xing; Liu, Bo; Jing, Liang; Chen, Bing

2018-04-01

In this study, shrimp waste was enzymatically hydrolyzed to generate a green dispersant and the product was tested for crude oil dispersion in seawater. The hydrolysis process was first optimized based on the dispersant effectiveness (DE) of the product. The functional properties of the product were identified including stability, critical micelle concentration, and emulsification activity. Water was confirmed as a good solvent for dispersant generation when compared with three chemical solvents. The effects of salinity, mixing energy, and temperature on the dispersion of the Alaska North Slope (ANS) crude oil were examined. Microtox acute toxicity test was also conducted to evaluate the toxicity of the produced dispersant. In addition, DE of the product on three different types of crude oil, including ANS crude oil, Prudhoe Bay crude oil (PBC), and Arabian Light crude oil (ALC) was compared with that of the Corexit 9500, respectively. The research output could lead to a promising green solution to the oil spill problem and might result in many other environmental applications.

Effects of temperature and wave conditions on chemical dispersion efficacy of heavy fuel oil in an experimental flow-through wave tank.

PubMed

Li, Zhengkai; Lee, Kenneth; King, Thomas; Boufadel, Michel C; Venosa, Albert D

2010-09-01

The effectiveness of chemical dispersants (Corexit 9500 and SPC 1000) on heavy fuel oil (IFO180 as test oil) has been evaluated under different wave conditions in a flow-through wave tank. The dispersant effectiveness was determined by measuring oil concentrations and droplet size distributions. An analysis of covariance (ANCOVA) model indicated that wave type and temperature significantly (p<0.05) affected the dynamic dispersant effectiveness (DDE). At higher temperatures (16 degrees C), the test IFO180 was effectively dispersed under breaking waves with a DDE of 90% and 50% for Corexit 9500 and SPC 1000, respectively. The dispersion was ineffective under breaking waves at lower temperature (10 degrees C), and under regular wave conditions at all temperatures (10-17 degrees C), with DDE<15%. Effective chemical dispersion was associated with formation of smaller droplets (with volumetric mean diameters or VMD < or = 200 microm), whereas ineffective dispersion produced large oil droplets (with VMD > or = 400 microm). Copyright 2010 Elsevier Ltd. All rights reserved.

An effective dispersant for oil spills based on food-grade amphiphiles.

PubMed

Athas, Jasmin C; Jun, Kelly; McCafferty, Caitlyn; Owoseni, Olasehinde; John, Vijay T; Raghavan, Srinivasa R

2014-08-12

Synthetic dispersants such as Corexit 9500A were used in large quantities (∼2 million gallons) to disperse the oil spilled in the ocean during the recent Deepwater Horizon event. These dispersant formulations contain a blend of surfactants in a base of organic solvent. Some concerns have been raised regarding the aquatic toxicity and environmental impact of these formulations. In an effort to create a safer dispersant, we have examined the ability of food-grade amphiphiles to disperse (emulsify) crude oil in seawater. Our studies show that an effective emulsifier is obtained by combining two such amphiphiles: lecithin (L), a phospholipid extracted from soybeans, and Tween 80 (T), a surfactant used in many food products including ice cream. Interestingly, we find that L/T blends show a synergistic effect, i.e., their combination is an effective emulsifier, but neither L or T is effective on its own. This synergy is maximized at a 60/40 weight ratio of L/T and is attributed to the following reasons: (i) L and T pack closely at the oil-water interface; (ii) L has a low tendency to desorb, which fortifies the interfacial film; and (iii) the large headgroup of T provides steric repulsions between the oil droplets and prevents their coalescence. A comparison of L/T with Corexit 9500A shows that the former leads to smaller oil droplets that remain stable to coalescence for a much longer time. The smaller size and stability of crude oil droplets are believed to be important to their dispersion and eventual microbial degradation in the ocean. Our findings suggest that L/T blends could potentially be a viable alternative for the dispersion of oil spills.

Determining Which Dispersants Will Be Effective In Future Deepwater Oil Spills

EPA Science Inventory

Deepwater spills result in oil distributed from deep in the water column to the water surface. The objective of this study was to test eight of the available dispersants (including Corexit 9500A, which was used extensively on the 2010 Deepwater Horizon Spill) on South Louisiana C...

Presence of the Corexit component dioctyl sodium sulfosuccinate in Gulf of Mexico waters after the 2010 Deepwater Horizon oil spill

USGS Publications Warehouse

Gray, James L.; Kanagy, Leslie K.; Furlong, Edward T.; Kanagy, Chris J.; McCoy, Jeff W.; Mason, Andrew; Lauenstein, Gunnar

2014-01-01

Between April 22 and July 15, 2010, approximately 4.9 million barrels of oil were released into the Gulf of Mexico from the Deepwater Horizon oil well. Approximately 16% of the oil was chemically dispersed, at the surface and at 1500 m depth, using Corexit 9527 and Corexit 9500, which contain dioctyl sodium sulfosuccinate (DOSS) as a major surfactant component. This was the largest documented release of oil in history at substantial depth, and the first time large quantities of dispersant (0.77 million gallons of approximately 1.9 million gallons total) were applied to a subsurface oil plume. During two cruises in late May and early June, water samples were collected at the surface and at depth for DOSS analysis. Real-time fluorimetry data was used to infer the presence of oil components to select appropriate sampling depths. Samples were stored frozen and in the dark for approximately 6 months prior to analysis by liquid chromatography/tandem mass spectrometry with isotope-dilution quantification. The blank-limited method detection limit (0.25 μg L−1) was substantially less than the U.S. Environmental Protection Agency’s (USEPA) aquatic life benchmark of 40 μg L−1. Concentrations of DOSS exceeding 200 μg L−1 were observed in one surface sample near the well site; in subsurface samples DOSS did not exceed 40 μg L−1. Although DOSS was present at high concentration in the immediate vicinity of the well where it was being continuously applied, a combination of biodegradation, photolysis, and dilution likely reduced persistence at concentrations exceeding the USEPA aquatic life benchmark beyond this immediate area.

Toxicity of oil dispersant, crude oil and dispersed crude oil to a marine amphipod and gastropod

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gulec, I.; Holdway, D.A.

1995-12-31

The importance of appropriate oil spill remedial action was emphasized during the recent Iron Barron oil spill off of the Tamar river in North Tasmania. One important potential oil spill response is dispersion, but little information exists on the toxicity of dispersants and dispersed oil to Australian marine species. This research was undertaken to assess the acute toxicity of Corexit 9527 (a widely used dispersant), water accommodated fractions of Bass Strait crude oil and dispersed Bass Strait crude oil, to the saltwater amphipod, Allorchestes compressa under semi-static conditions. Acute 96 h LC50`s were determined for each toxicant as well asmore » for the reference toxicants sodium dodecyl sulfate (SDS) and zinc sulfate. Sublethal bioassays were undertaken for the same 3 toxicants utilizing the marines and snail Polinices conicus as the test species. No-observed-effect-concentrations (NOEC) and lowest-observed-effect-concentrations (LOEC) were determined using ANOVA while EC50`s and EC0`s were calculated using regression analysis. Mean acute 96 h LC50 (S.E.) values for A. compressa exposed to SDS and zinc sulfate were 3.6 mg/l (0.28) and 41.6 mg/l (9.01) respectively. EC50 (S.E.) concentrations for P. conicus exposed to SDS and zinc sulfate for 30 minutes were 44.7 mg/l and 246 mg/l respectively using burying behavior as an endpoint. These sublethal EC50`s were reduced to 20.7 mg/l for SDS and 23.5 mg/l for zinc sulfate following 24 hours of exposure.« less

Oil and related toxicant effects on mallard immune defenses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rocke, T.E.; Yuill, T.M.; Hinsdill, R.D.

A crude oil, a petroleum distillate, and chemically dispersed oil were tested for their effects on resistance to bacterial infection and the immune response in waterfowl. Sublethal oral doses for mallards were determined for South Louisiana crude oil, Bunker C fuel oil a dispersant-Corexit 9527, and oil/Corexit combinations by gizzard intubation. Resistance to bacterial challange (Pasteurella multocida) was significantly lowered in mallards receiving 2.5 or 4.0 ml/kg of Bunker C fuel oil, 4.0 ml/kg of South Louisiana crude oil, and 4.0 ml/kg of a 50:1 Bunker C fuel oil/Corexit mixture daily for 28 days. Ingestion of oil or oil/Corexit mixturesmore » had no effect on mallard antibody-producing capability as measured by the direct spleen plaque-forming assay.« less

Comparative Laboratory-Scale Testing of Dispersant Effectiveness of 23 Crude Oils Using Four Different Testing Protocols

EPA Science Inventory

A controlled laboratory study was conducted to measure the dispersion effectiveness of Corexit 9500 on 20 different crude oils. This study was a part of a larger project initiated by the Bureau of Safety and Environmental Enforcement (BSEE) testing 20 oils to compare the predict...

Effects of oil and dispersant on formation of marine oil snow and transport of oil hydrocarbons.

PubMed

Fu, Jie; Gong, Yanyan; Zhao, Xiao; O'Reilly, S E; Zhao, Dongye

2014-12-16

This work explored the formation mechanism of marine oil snow (MOS) and the associated transport of oil hydrocarbons in the presence of a stereotype oil dispersant, Corexit EC9500A. Roller table experiments were carried out to simulate natural marine processes that lead to formation of marine snow. We found that both oil and the dispersant greatly promoted the formation of MOS, and MOS flocs as large as 1.6-2.1 mm (mean diameter) were developed within 3-6 days. Natural suspended solids and indigenous microorganisms play critical roles in the MOS formation. The addition of oil and the dispersant greatly enhanced the bacterial growth and extracellular polymeric substance (EPS) content, resulting in increased flocculation and formation of MOS. The dispersant not only enhanced dissolution of n-alkanes (C9-C40) from oil slicks into the aqueous phase, but facilitated sorption of more oil components onto MOS. The incorporation of oil droplets in MOS resulted in a two-way (rising and sinking) transport of the MOS particles. More lower-molecular-weight (LMW) n-alkanes (C9-C18) were partitioned in MOS than in the aqueous phase in the presence of the dispersant. The information can aid in our understanding of dispersant effects on MOS formation and oil transport following an oil spill event.

The primary biodegradation of dispersed crude oil in the sea.

PubMed

Prince, Roger C; McFarlin, Kelly M; Butler, Josh D; Febbo, Eric J; Wang, Frank C Y; Nedwed, Tim J

2013-01-01

Dispersants are important tools for stimulating the biodegradation of large oil spills. They are essentially a bioremediation tool - aiming to stimulate the natural process of aerobic oil biodegradation by dispersing oil into micron-sized droplets that become so dilute in the water column that the natural levels of biologically available nitrogen, phosphorus and oxygen are sufficient for microbial growth. Many studies demonstrate the efficacy of dispersants in getting oil off the water surface. Here we show that biodegradation of dispersed oil is prompt and extensive when oil is present at the ppm levels expected from a successful application of dispersants - more than 80% of the hydrocarbons of lightly weathered Alaska North Slope crude oil were degraded in 60 d at 8 °C in unamended New Jersey (USA) seawater when the oil was present at 2.5 ppm by volume. The apparent halftime of the biodegradation of the hydrocarbons was 13.8 d in the absence of dispersant, and 11 d in the presence of Corexit 9500 - similar to rates extrapolated from the field in the Deepwater Horizon response. Copyright © 2012 Elsevier Ltd. All rights reserved.

Oil viscosity limitation on dispersibility of crude oil under simulated at-sea conditions in a large wave tank.

PubMed

Trudel, Ken; Belore, Randy C; Mullin, Joseph V; Guarino, Alan

2010-09-01

This study determined the limiting oil viscosity for chemical dispersion of oil spills under simulated sea conditions in the large outdoor wave tank at the US National Oil Spill Response Test Facility in New Jersey. Dispersant effectiveness tests were completed using crude oils with viscosities ranging from 67 to 40,100 cP at test temperature. Tests produced an effectiveness-viscosity curve with three phases when oil was treated with Corexit 9500 at a dispersant-to-oil ratio of 1:20. The oil viscosity that limited chemical dispersion under simulated at-sea conditions was in the range of 18,690 cP to 33,400 cP. Visual observations and measurements of oil concentrations and droplet size distributions in the water under treated and control slicks correlated well with direct measurements of effectiveness. The dispersant effectiveness versus oil viscosity relationship under simulated at sea conditions at Ohmsett was most similar to those from similar tests made using the Institut Francais du Pétrole and Exxon Dispersant Effectiveness (EXDET) test methods. Copyright 2010 Elsevier Ltd. All rights reserved.

Acute and chronic toxicity study of the water accommodated fraction (WAF), chemically enhanced WAF (CEWAF) of crude oil and dispersant in the rock pool copepod Tigriopus japonicus.

PubMed

Lee, Kyun-Woo; Shim, Won Joon; Yim, Un Hyuk; Kang, Jung-Hoon

2013-08-01

We determined the toxicity of the water accommodated hydrocarbon fraction (WAF), two chemically enhanced WAFs (CEWAFs; CEWAF-C, Crude oil+Corexit 9500 and CEWAF-H, Crude oil+Hiclean) of crude oil and two dispersants (Corexit 9500 and Hiclean) to the rock pool copepod Tigriopus japonicus. In the acute toxicity test, Corexit 9500 was the most toxic of all the chemicals studied. The nauplius stage of T. japonicus was more susceptible to the toxic chemicals studied than the adult female. The toxicity data using the nauplius stage was then considered as baseline to determine the spiking concentration of chemicals for chronic toxicity tests on the copepod. As the endpoints in the chronic toxicity test, survival, sex ratio, developmental time and fecundity of the copepod were used. All chemicals used in this study resulted in increased toxicity in the F1 generation. The lowest-observed-adverse-effect (LOAE) concentrations of WAF, CEWAF-H, CEWAF-C, Hiclean and Corexit 9500 were observed to be 50%, 10%, 0.1%, 1% and 1%, respectively. The results in present study imply that copepods in marine may be negatively influenced by spilled oil and dispersant. Copyright © 2013 Elsevier Ltd. All rights reserved.

A protocol for assessing the effectiveness of oil spill dispersants in stimulating the biodegradation of oil.

PubMed

Prince, Roger C; Butler, Josh D

2014-01-01

Dispersants are important tools in oil spill response. Taking advantage of the energy in even small waves, they disperse floating oil slicks into tiny droplets (<70 μm) that entrain in the water column and drift apart so that they do not re-agglomerate to re-form a floating slick. The dramatically increased surface area allows microbial access to much more of the oil, and diffusion and dilution lead to oil concentrations where natural background levels of biologically available oxygen, nitrogen, and phosphorus are sufficient for microbial growth and oil consumption. Dispersants are only used on substantial spills in relatively deep water (usually >10 m), conditions that are impossible to replicate in the laboratory. To date, laboratory experiments aimed at following the biodegradation of dispersed oil usually show only minimal stimulation of the rate of biodegradation, but principally because the oil in these experiments disperses fairly effectively without dispersant. What is needed is a test protocol that allows comparison between an untreated slick that remains on the water surface during the entire biodegradation study and dispersant-treated oil that remains in the water column as small dispersed oil droplets. We show here that when this is accomplished, the rate of biodegradation is dramatically stimulated by an effective dispersant, Corexit 9500. Further development of this approach might result in a useful tool for comparing the full benefits of different dispersants.

The impact of oil spill to lung health – insights from an RNA-seq study of human airway epithelial cells

PubMed Central

Liu, Yao-Zhong; Roy-Engel, Astrid M; Baddoo, Melody C; Flemington, Erik K; Wang, Guangdi; Wang, He

2015-01-01

The Deepwater Horizon oil spill (BP oil spill) in the Gulf of Mexico was a unique disaster event, where a huge amount of oil spilled from the sea bed and a large volume of dispersants were applied to clean the spill. The operation lasted for almost three months and involved >50,000 workers. The potential health hazards to these workers may be significant as previous research suggested an association of persistent respiratory symptoms with exposure to oil and oil dispersants. To reveal the potential effects of oil and oil dispersants on the respiratory system at the molecular level, we evaluated the transcriptomic profile of human airway epithelial cells grown under treatment of crude oil, the dispersants Corexit 9500 and Corexit 9527 and oil-dispersant mixtures. We identified a very strong effect of Corexit 9500 treatment, with 84 genes (response genes) differentially expressed in treatment vs. control samples. We discovered an interactive effect of oil-dispersant mixtures; while no response gene was found for Corexit 9527 treatment alone, cells treated with Corexit 9527 + oil mixture showed an increased number of response genes (46 response genes), suggesting a synergic effect of 9527 with oil on airway epithelial cells. Through GO (gene ontology) functional term and pathway-based analysis, we identified upregulation of gene sets involved in angiogenesis and immune responses and downregulation of gene sets involved in cell junctions and steroid synthesis as the prevailing transcriptomic signatures in the cells treated with Corexit 9500, oil or Corexit 9500 + oil mixture. Interestingly, these key molecular signatures coincide with important pathological features observed in common lung diseases, such as asthma, cystic fibrosis and chronic obstructive pulmonary disease. Our study provides mechanistic insights into the detrimental effects of oil and oil dispersants to the respiratory system and suggests significant health impacts of the recent BP oil spill to those

Evaluation of the ability of calcite, bentonite and barite to enhance oil dispersion under arctic conditions.

PubMed

Jézéquel, Ronan; Receveur, Justine; Nedwed, Tim; Le Floch, Stéphane

2018-02-01

A test program was conducted at laboratory and pilot scale to assess the ability of clays used in drilling mud (calcite, bentonite and barite) to create oil-mineral aggregates and disperse crude oil under arctic conditions. Laboratory tests were performed in order to determine the most efficient conditions (type of clay, MOR (Mineral/Oil Ratio), mixing energy) for OMA (Oil Mineral Aggregate) formation. The dispersion rates of four crude oils were assessed at two salinities. Dispersion was characterized in terms of oil concentration in the water column and median OMA size. Calcite appeared to be the best candidate at a MOR of 2:5. High mixing energy was required to initiate OMA formation and low energy was then necessary to prevent the OMAs from resurfacing. Oil dispersion using Corexit 9500 was compared with oil dispersion using mineral fines. Copyright © 2017 Elsevier Ltd. All rights reserved.

Response of deep-water corals to oil and chemical dispersant exposure

NASA Astrophysics Data System (ADS)

DeLeo, Danielle M.; Ruiz-Ramos, Dannise V.; Baums, Iliana B.; Cordes, Erik E.

2016-07-01

Cold-water corals serve as important foundation species by building complex habitat within deep-sea benthic communities. Little is known about the stress response of these foundation species yet they are increasingly exposed to anthropogenic disturbance as human industrial presence expands further into the deep sea. A recent prominent example is the Deepwater Horizon oil-spill disaster and ensuing clean-up efforts that employed chemical dispersants. This study examined the effects of bulk oil-water mixtures, water-accommodated oil fractions, the dispersant Corexit 9500A®, and the combination of hydrocarbons and dispersants on three species of corals living near the spill site in the Gulf of Mexico between 500 and 1100 m depths: Paramuricea type B3, Callogorgia delta and Leiopathes glaberrima. Following short-term toxicological assays (0-96 h), all three coral species examined showed more severe health declines in response to dispersant alone (2.3-3.4 fold) and the oil-dispersant mixtures (1.1-4.4 fold) than in the oil-only treatments. Higher concentrations of dispersant alone and the oil-dispersant mixtures resulted in more severe health declines. C. delta exhibited somewhat less severe health declines than the other two species in response to oil and oil/dispersant mixture treatments, likely related to its increased abundance near natural hydrocarbon seeps. These experiments provide direct evidence for the toxicity of both oil and dispersant on deep-water corals, which should be taken into consideration in the development of strategies for intervention in future oil spills.

Effects of oil dispersants on photodegradation of pyrene in marine water.

PubMed

Gong, Yanyan; Fu, Jie; O'Reilly, S E; Zhao, Dongye

2015-04-28

This work investigated effects of a popular oil dispersant (Corexit EC9500A) on UV- or sunlight-mediated photodegradation of pyrene (a model polycyclic aromatic hydrocarbon) in seawater. The presence of 18 and 180mg/L of the dispersant increased the first-order photodegradation rate by 5.5% and 16.7%, respectively, and reduced or ceased pyrene volatilization. By combining individual first-order rate laws for volatilization and photodegradation, we proposed an integrated kinetic model that can adequately predict the overall dissipation of pyrene from seawater. Mechanistic studies indicated that superoxide radicals played a predominant role in pyrene photodegradation, and the dispersant enhanced formation of superoxide radicals. 1-Hydroxypyrene was the main intermediate regardless of the dispersant, suggesting that electrons were transferred from excited pyrene to oxygen. In the presence of 18mg/L of the dispersant, the photodegradation rate increased with increasing ionic strength and temperature, but decreased with increasing HA concentration, and remained independent of solution pH. The results are important in understanding roles of oil dispersants on environmental fate of persistent oil components in natural and engineered systems. Copyright © 2015 Elsevier B.V. All rights reserved.

Oil spill dispersants induce formation of marine snow by phytoplankton-associated bacteria.

PubMed

van Eenennaam, Justine S; Wei, Yuzhu; Grolle, Katja C F; Foekema, Edwin M; Murk, AlberTinka J

2016-03-15

Unusually large amounts of marine snow, including Extracellular Polymeric Substances (EPS), were formed during the 2010 Deepwater Horizon oil spill. The marine snow settled with oil and clay minerals as an oily sludge layer on the deep sea floor. This study tested the hypothesis that the unprecedented amount of chemical dispersants applied during high phytoplankton densities in the Gulf of Mexico induced high EPS formation. Two marine phytoplankton species (Dunaliella tertiolecta and Phaeodactylum tricornutum) produced EPS within days when exposed to the dispersant Corexit 9500. Phytoplankton-associated bacteria were shown to be responsible for the formation. The EPS consisted of proteins and to lesser extent polysaccharides. This study reveals an unexpected consequence of the presence of phytoplankton. This emphasizes the need to test the action of dispersants under realistic field conditions, which may seriously alter the fate of oil in the environment via increased marine snow formation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Application of fluorescence and PARAFAC to assess vertical distribution of subsurface hydrocarbons and dispersant during the Deepwater Horizon oil spill.

PubMed

Mendoza, Wilson G; Riemer, Daniel D; Zika, Rod G

2013-05-01

We evaluated the use of excitation and emission matrix (EEM) fluorescence and parallel factorial analysis (PARAFAC) modeling techniques for monitoring crude oil components in the water column. Four of the seven derived PARAFAC loadings were associated with the Macondo crude oil components. The other three components were associated with the dispersant, an unresolved component and colored dissolved organic matter (CDOM). The fluorescence of the associated benzene and naphthalene-like components of crude oil exhibited a maximum at ∼1200 m. The maximum fluorescence of the component associated with the dispersant (i.e., Corexit EC9500A) was observed at the same depth. The plume observed at this depth was attributed to the dispersed crude oil from the Deepwater Horizon oil spill. Results demonstrate the application of EEM and PARAFAC to simultaneously monitor selected PAH, dispersant-containing and humic-like fluorescence components in the oil spill region in the Gulf of Mexico.

Chemically-dispersed crude oil and dispersant affects sperm fertilizing ability, but not sperm swimming behaviour in capelin (Mallotus villosus).

PubMed

Beirão, José; Litt, Margaret A; Purchase, Craig F

2018-06-05

The effects of petroleum aromatic hydrocarbons (PAHs) on the embryonic and larval life stages of teleosts have been extensively examined. However, very little work has been conducted on how spilled oil affects fish sperm and there is no related knowledge concerning oil dispersing agents. The objective of our study was to determine sperm performance of a teleost fish under direct exposure to different concentrations of WAF (water accommodated fraction) and CEWAF (chemically enhanced water accommodated fraction). Capelin sperm motility, swimming behaviour, and sperm fertilization ability were evaluated in a scenario of an oil spill untreated (WAF) and treated (CEWAF) with the dispersant Corexit ® EC9500A. Sperm fertilizing ability was lower when exposed to CEWAF concentrations of 16.1 × 10 3  μg/L total petroleum hydrocarbons and 47.9 μg/L PAH, and when exposed to the dispersant alone. The mechanism responsible for this reduced fertilizing ability is not clear. However, it is not related to the percentage of motile sperm or sperm swimming behaviour, as these were unaffected. WAF did not alter sperm swimming characteristics nor the fertilizing ability. We suggest the dispersant rather than the dispersed oil is responsible for the decrease in the sperm fertilizing ability and hypothesize that the surfactants present in the dispersant affect sperm membrane functionality. Copyright © 2018. Published by Elsevier Ltd.

A field experiment to assess impact of chemically dispersed oil on Arabian Gulf corals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Le Gore, R.S.; Cuddeback, J.E.; Hofmann, J.E.

1983-03-01

Field experiments were conducted on a coral reef at Jurayd Island (Saudi Arabia) in the Arabian Gulf to study the effects of chemically dispersed oil on local corals. Portions of the reef were exposed to predetermined concentrations of oil alone, dispersant alone, and oil-plus-dispersant mixtures. Areas of the reef not exposed to any of the toxicants were used as controls. Arabian Light Crude and Corexit 9527 dispersant were the test toxicants. Two series of experiments were conducted beginning in September 1981, one with a 24-hour exposure period and the other with a 5-day (120-hour) exposure period. Corals were stained formore » growth rate studies and extensively photographed to document any observed effects. Corals were examined for biological impacts immediately after the exposures, and then at 3-month intervals for 1 year. Water temperature, salinity, dissolved oxygen, and hydrocarbon content were recorded during the exposure periods. Coral growth appeared unaffected by exposure to the toxicants. Some Acropora species corals exposed to dispersed oil for 5 days exhibited delayed effects, which became apparent during the relatively cold winter season.« less

Lethal and sub-lethal effects of Deepwater Horizon slick oil and dispersant on oyster (Crassostrea virginica) larvae.

PubMed

Vignier, J; Soudant, P; Chu, F L E; Morris, J M; Carney, M W; Lay, C R; Krasnec, M O; Robert, R; Volety, A K

2016-09-01

In April 2010, crude oil was spilled from the Deepwater Horizon (DWH) oil platform for 87 days, coincident with the spawning season and recruitment of the oyster, Crassostrea virginica, in the Gulf of Mexico. Impacts of acute exposures to surface-collected DWH oil (HEWAF), dispersed oil (CEWAF) and dispersant alone (Corexit 9500A(®)) on planktonic larval stages of C. virginica (veliger, umbo and pediveliger) were tested in the laboratory. Exposures to HEWAF, CEWAF and dispersant were toxic to larvae impairing growth, settlement success and ultimately survival. Larval growth and settlement were reduced at concentrations of tPAH50 ranging from 1.7 to 106 μg L(-1) for HEWAF and 1.1-35 μg L(-1) for CEWAF, concentrations well within the range of water sampled during the DWH oil spill. Sublethal effects induced by oil and dispersant could have significant ecological implications on oyster populations and on the whole estuarine ecosystem. Copyright © 2016 Elsevier Ltd. All rights reserved.

Photochemical degradation of Corexit components in ocean water.

PubMed

Glover, Caitlin M; Mezyk, Stephen P; Linden, Karl G; Rosario-Ortiz, Fernando L

2014-09-01

Due to the large quantities of dispersants used during the Deepwater Horizon spill in 2010, there were immediate concerns with regards to the fate and transport of the mixture in ocean waters. Direct and sensitized photolysis experiments were carried out for two compounds chosen as surrogates for the Corexit mixture (9500 and 9527) that were applied to surface waters during the oil spill in the Gulf of Mexico. The results showed that direct photolysis did not contribute significantly to the overall degradation (max ∼30%), therefore the focus shifted to sensitized photolysis, specifically the degradation stemming from the reaction rate with hydroxyl radical (HO). The direct photochemical degradation rates for two of the compounds, dioctyl sulfosuccinate (DOSS) and dipropylene glycol butyl ether (DGBE) were measured as 4.29×10(-6)s(-1) and 5.95×10(-6)s(-1), respectively; whereas the overall degradation rate in ocean water was 1.56×10(-5)s(-1) and 2.23×10(-5)s(-1). The formation rates and apparent quantum yields for HO formation were determined for six ocean water samples. The values ranged from 1.81×10(-5) near shore to 0.061×10(-5) for the open ocean. These degradation rates suggest the possibility for photolysis to play a role in the overall fate of Corexit. Copyright © 2014 Elsevier Ltd. All rights reserved.

Influence of UVB radiation on the lethal and sublethal toxicity of dispersed crude oil to planktonic copepod nauplii.

PubMed

Almeda, Rodrigo; Harvey, Tracy E; Connelly, Tara L; Baca, Sarah; Buskey, Edward J

2016-06-01

Toxic effects of petroleum to marine zooplankton have been generally investigated using dissolved petroleum hydrocarbons and in the absence of sunlight. In this study, we determined the influence of natural ultraviolet B (UVB) radiation on the lethal and sublethal toxicity of dispersed crude oil to naupliar stages of the planktonic copepods Acartia tonsa, Temora turbinata and Pseudodiaptomus pelagicus. Low concentrations of dispersed crude oil (1 μL L(-1)) caused a significant reduction in survival, growth and swimming activity of copepod nauplii after 48 h of exposure. UVB radiation increased toxicity of dispersed crude oil by 1.3-3.8 times, depending on the experiment and measured variables. Ingestion of crude oil droplets may increase photoenhanced toxicity of crude oil to copepod nauplii by enhancing photosensitization. Photoenhanced sublethal toxicity was significantly higher when T. turbinata nauplii were exposed to dispersant-treated oil than crude oil alone, suggesting that chemical dispersion of crude oil may promote photoenhanced toxicity to marine zooplankton. Our results demonstrate that acute exposure to concentrations of dispersed crude oil and dispersant (Corexit 9500) commonly found in the sea after oil spills are highly toxic to copepod nauplii and that natural levels of UVB radiation substantially increase the toxicity of crude oil to these planktonic organisms. Overall, this study emphasizes the importance of considering sunlight in petroleum toxicological studies and models to better estimate the impact of crude oil spills on marine zooplankton. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Effect of dispersants on the biodegradation of South Louisiana crude oil at 5 and 25 °C.

PubMed

Zhuang, Mobing; Abulikemu, Gulizhaer; Campo, Pablo; Platten, William E; Suidan, Makram T; Venosa, Albert D; Conmy, Robyn N

2016-02-01

This article reports biodegradation rates for a commercial dispersant, JD-2000, South Louisiana crude oil (SLC) alone, and SLC dispersed with JD-2000 at 5 and 25 °C. Results from the biodegradation experiments revealed that Component X, a chemical marker for JD-2000, rapidly degraded at both temperatures. The application of JD-2000 decreased by half the overall biodegradation rate of aliphatic compounds at 25 °C. At 5 °C, a residual fraction consisting of iso- and n-alkanes (C29-C35) persisted after 56 d. The combination of dispersant and higher temperature resulted in faster removal rates for 2- and 3-ring polycyclic aromatic hydrocarbons. When compared with Corexit 9500, our results suggest that the chemistry of the surfactant (or surfactants) in JD-2000 might have favored oil dissolution (substrate transport to the aqueous phase) as an uptake mechanism over adhesion, which requires direct contact of the biomass with the oil. Copyright © 2015 Elsevier Ltd. All rights reserved.

Responses of the soft coral Xenia elongata following acute exposure to a chemical dispersant.

PubMed

Studivan, Michael S; Hatch, Walter I; Mitchelmore, Carys L

2015-01-01

Limited toxicology data are available regarding oil dispersant exposure to coral species. Corexit® EC9500A (Corexit) is a commonly applied dispersant most well known for its use after the Deepwater Horizon spill in April, 2010. There is limited evidence that Corexit can cause a bleaching response in corals. The aims of the study were: (1) to determine the extent of bleaching after acute 24 h and 72 h exposures of sublethal concentrations (0-50 ppm) of Corexit to the pulsing soft coral Xenia elongata and (2) to investigate a percent symbiont loss calculation using zooxanthellae density. The percent symbiont loss calculation was compared to a traditional metric of normalizing zooxanthellae density to soluble protein content. Percent symbiont loss was an effective measure of coral stress in acute Corexit exposures, while protein normalized zooxanthellae density was more variable. The bleaching data suggest a positive relationship between dispersant concentration and percent symbiont loss, culminating in excessive tissue necrosis and coral mortality within 72 h in high concentration exposures (p < 0.001). Percent beaching ranged from 25% in 5 ppm exposures to 100% in 50 ppm exposures. Corexit also caused a significant decrease in pulse activity (p < 0.0001) and relative oxygen saturation (p < 0.001), possibly indicating a reduction in photosynthetic efficiency. This study and other similar research indicate that dispersant exposure is highly damaging to marine organisms, including ecologically important coral species.

Determining the presence of dipropylene glycol n-butyl ether (DPnB) in sediments and sands contaminated by the Deepwater Horizon (DWH) oil spill

NASA Astrophysics Data System (ADS)

Boehman, B.; Lyons, S. L.; Geng, Z.; White, H. K.

2016-02-01

In an attempt to mitigate the impact of the oil released from the Deepwater Horizon (DWH) oil spill, chemical dispersants (Corexit 9527 and Corexit 9500A, from Nalco Co.) were applied to the surface and subsurface waters of the Gulf of Mexico. Over the past five years studies have investigated the fate of oil from the spill and the applied dispersants, although significantly less is known about the latter. To determine the presence of dispersant in environmental samples, dioctyl sodium sulfosuccinate (DOSS), a component of both Corexit mixtures, has previously been examined in samples taken from the water column, coastal beaches and deep-sea sediments. This study expands upon this work by developing a method to extract dipropylene glycol n-butyl ether (DPnB), an additional compound present in Corexit, from sand and sediment samples contaminated with oil from the DWH spill. Controls spiked with a known quantity of DPnB were extracted with a range of organic solvents of different polarities to optimize the extraction of DPnB. Total organic extracts were then subjected to silica gel chromatography to isolate DPnB from any oil that was co-extracted. All samples were concentrated prior to analysis via gas chromatography mass spectrometry (GC/MS) using selected ion monitoring (SIM). The analysis and quantification of DPnB, which has different chemical properties than DOSS, will provide additional insight into the mechanisms that control the fate of oil and dispersant mixtures in the marine environment.

Analysis of Eight Oil Spill Dispersants Using Rapid, In Vitro ...

EPA Pesticide Factsheets

The Deepwater Horizon oil spill has led to the use of >1 M gallons of oil spill dispersants, which are mixtures of surfactants and solvents. Because of this large scale use there is a critical need to understand the potential for toxicity of the currently used dispersant and potential alternatives, especially given the limited toxicity testing information that is available. In particular, some dispersants contain nonylphenol ethoxylates (NPEs), which can degrade to nonylphenol (NP), a known endocrine disruptor. Given the urgent need to generate toxicity data, we carried out a series of in vitro high-throughput assays on eight commercial dispersants. These assays focused on the estrogen and androgen receptors (ER and AR), but also included a larger battery of assays probing other biological pathways. Cytotoxicity in mammalian cells was also quantified. No activity was seen in any AR assay. Two dispersants showed a weak ER signal in one assay (EC50 of 16 ppm for Nokomis 3-F4 and 25 ppm for ZI-400). NPs and NPEs also had a weak signal in this same ER assay. Note that Corexit 9500, the currently used product, does not contain NPEs and did not show any ER activity. Cytotoxicity values for six of the dispersants were statistically indistinguishable, with median LC50 values ∼100 ppm. Two dispersants, JD 2000 and SAFRON GOLD, were significantly less cytotoxic than the others with LC50 values approaching or exceeding 1000 ppm. EPA’s Office of Research and Developme

The acute toxicity of chemically and physically dispersed crude oil to key arctic species under arctic conditions during the open water season

PubMed Central

Gardiner, William W; Word, Jack Q; Word, Jack D; Perkins, Robert A; McFarlin, Kelly M; Hester, Brian W; Word, Lucinda S; Ray, Collin M

2013-01-01

The acute toxicity of physically and chemically dispersed crude oil and the dispersant Corexit 9500 were evaluated for key Arctic species. The copepod Calanus glacialis, juvenile Arctic cod (Boreogadus saida), and larval sculpin (Myoxocephalus sp.) were tested under conditions representative of the Beaufort and Chukchi Seas during the ice-free season. The toxicity of 3 water-accommodated fractions (WAF) of Alaska North Slope crude oil was examined with spiked, declining exposures. A dispersant-only test was conducted with the copepod C. glacialis. Each preparation with oil (WAF, breaking wave WAF [BWWAF], and chemically enhanced WAF [CEWAF]) produced distinct suites of hydrocarbon constituents; the total concentrations of oil were lowest in WAF and highest in CEWAF preparations. The relative sensitivity for the different species and age classes was similar within each WAF type. Median lethal concentration values based on total petroleum hydrocarbons ranged from 1.6 mg/L to 4.0 mg/L for WAF and BWWAF treatments and from 22 mg/L to 62 mg/L for CEWAF. For Corexit 9500 exposures, median lethal concentration values ranged from 17 mg/L to 50 mg/L. The differences in the relative toxicity among the accommodated fractions indicated that the majority of petroleum hydrocarbons in the CEWAF are in less acutely toxic forms than the components that dominate the WAF or BWWAF. Further evaluation showed that the parent polycyclic aromatic hydrocarbon compounds, specifically naphthalene, were highly correlated to acute toxicity. Environ Toxicol Chem 2013;32:2284–2300. PMID:23765555

Phototoxic potential of undispersed and dispersed fresh and weathered Macondo crude oils to Gulf of Mexico Marine Organisms.

PubMed

Finch, Bryson E; Marzooghi, Solmaz; Di Toro, Dominic M; Stubblefield, William A

2017-10-01

Crude oils contain a mixture of hydrocarbons, including phototoxic polycyclic aromatic hydrocarbons (PAHs) that have the ability to absorb ultraviolet (UV) light. Absorption of UV light by PAHs can substantially increase their toxicity to marine organisms. The objective of the present study was to examine the potential for phototoxicity of fresh and naturally weathered Macondo crude oils alone and in combination with the dispersant Corexit 9500 to mysid shrimp (Americamysis bahia), inland silverside (Menidia beryllina), sheepshead minnow (Cyprinodon variegatus), and Gulf killifish (Fundulus grandis). Acute toxicity tests were conducted using combinations of natural or artificial sunlight and low-energy water-accommodated fractions (WAFs) of fresh and weathered Macondo crude oils collected from the Gulf of Mexico. Studies were also conducted to compare the phototoxicity resulting from natural and artificial sunlight. Fresh Macondo crude oil was more phototoxic than weathered crude oils, both in the presence and in the absence of UV light. Differences in toxicity between fresh and weathered crude oils were likely attributed to lighter-ringed PAHs in fresh crude oils. Phototoxic PAHs were relatively resistant to weathering compared with lighter-ringed PAHs. The addition of Corexit 9500 to crude oil increased toxicity compared with tests with crude oil alone, by increasing phototoxic PAH concentrations in WAFs. Macondo crude oils had the potential to be phototoxic to Gulf of Mexico marine organisms if specific light conditions and PAH concentrations were present during the Deepwater Horizon oil spill. Environ Toxicol Chem 2017;36:2640-2650. © 2017 SETAC. © 2017 SETAC.

Evaluating crude oil chemical dispersion efficacy in a flow-through wave tank under regular non-breaking wave and breaking wave conditions.

PubMed

Li, Zhengkai; Lee, Kenneth; King, Thomas; Boufadel, Michel C; Venosa, Albert D

2009-05-01

Testing dispersant effectiveness under conditions similar to that of the open environment is required for improvements in operational procedures and the formulation of regulatory guidelines. To this end, a novel wave tank facility was fabricated to study the dispersion of crude oil under regular non-breaking and irregular breaking wave conditions. This wave tank facility was designed for operation in a flow-through mode to simulate both wave- and current-driven hydrodynamic conditions. We report here an evaluation of the effectiveness of chemical dispersants (Corexit EC9500A and SPC 1000) on two crude oils (Medium South American [MESA] and Alaska North Slope [ANS]) under two different wave conditions (regular non-breaking and plunging breaking waves) in this wave tank. The dispersant effectiveness was assessed by measuring the water column oil concentration and dispersed oil droplet size distribution. In the absence of dispersants, nearly 8-19% of the test crude oils were dispersed and diluted under regular wave and breaking wave conditions. In the presence of dispersants, about 21-36% of the crude oils were dispersed and diluted under regular waves, and 42-62% under breaking waves. Consistently, physical dispersion under regular waves produced large oil droplets (volumetric mean diameter or VMD > or = 300 microm), whereas chemical dispersion under breaking waves created small droplets (VMD < or = 50 microm). The data can provide useful information for developing better operational guidelines for dispersant use and improved predictive models on dispersant effectiveness in the field.

Natural Sunlight Shapes Crude Oil-Degrading Bacterial Communities in Northern Gulf of Mexico Surface Waters

PubMed Central

Bacosa, Hernando P.; Liu, Zhanfei; Erdner, Deana L.

2015-01-01

Following the Deepwater Horizon (DWH) spill in 2010, an enormous amount of oil was observed in the deep and surface waters of the northern Gulf of Mexico. Surface waters are characterized by intense sunlight and high temperature during summer. While the oil-degrading bacterial communities in the deep-sea plume have been widely investigated, the effect of natural sunlight on those in oil polluted surface waters remains unexplored to date. In this study, we incubated surface water from the DWH site with amendments of crude oil, Corexit dispersant, or both for 36 days under natural sunlight in the northern Gulf of Mexico. The bacterial community was analyzed over time for total abundance, density of alkane and polycyclic aromatic hydrocarbon degraders, and community composition via pyrosequencing. Our results showed that, for treatments with oil and/or Corexit, sunlight significantly reduced bacterial diversity and evenness and was a key driver of shifts in bacterial community structure. In samples containing oil or dispersant, sunlight greatly reduced abundance of the Cyanobacterium Synechococcus but increased the relative abundances of Alteromonas, Marinobacter, Labrenzia, Sandarakinotalea, Bartonella, and Halomonas. Dark samples with oil were represented by members of Thalassobius, Winogradskyella, Alcanivorax, Formosa, Pseudomonas, Eubacterium, Erythrobacter, Natronocella, and Coxiella. Both oil and Corexit inhibited the Candidatus Pelagibacter with or without sunlight exposure. For the first time, we demonstrated the effects of light in structuring microbial communities in water with oil and/or Corexit. Overall, our findings improve understanding of oil pollution in surface water, and provide unequivocal evidence that sunlight is a key factor in determining bacterial community composition and dynamics in oil polluted marine waters. PMID:26648916

Natural Sunlight Shapes Crude Oil-Degrading Bacterial Communities in Northern Gulf of Mexico Surface Waters.

PubMed

Bacosa, Hernando P; Liu, Zhanfei; Erdner, Deana L

2015-01-01

Following the Deepwater Horizon (DWH) spill in 2010, an enormous amount of oil was observed in the deep and surface waters of the northern Gulf of Mexico. Surface waters are characterized by intense sunlight and high temperature during summer. While the oil-degrading bacterial communities in the deep-sea plume have been widely investigated, the effect of natural sunlight on those in oil polluted surface waters remains unexplored to date. In this study, we incubated surface water from the DWH site with amendments of crude oil, Corexit dispersant, or both for 36 days under natural sunlight in the northern Gulf of Mexico. The bacterial community was analyzed over time for total abundance, density of alkane and polycyclic aromatic hydrocarbon degraders, and community composition via pyrosequencing. Our results showed that, for treatments with oil and/or Corexit, sunlight significantly reduced bacterial diversity and evenness and was a key driver of shifts in bacterial community structure. In samples containing oil or dispersant, sunlight greatly reduced abundance of the Cyanobacterium Synechococcus but increased the relative abundances of Alteromonas, Marinobacter, Labrenzia, Sandarakinotalea, Bartonella, and Halomonas. Dark samples with oil were represented by members of Thalassobius, Winogradskyella, Alcanivorax, Formosa, Pseudomonas, Eubacterium, Erythrobacter, Natronocella, and Coxiella. Both oil and Corexit inhibited the Candidatus Pelagibacter with or without sunlight exposure. For the first time, we demonstrated the effects of light in structuring microbial communities in water with oil and/or Corexit. Overall, our findings improve understanding of oil pollution in surface water, and provide unequivocal evidence that sunlight is a key factor in determining bacterial community composition and dynamics in oil polluted marine waters.

Study of residual oil in Bay Jimmy sediment 5 years after the Deepwater Horizon oil spill: Persistence of sediment retained oil hydrocarbons and effect of dispersants on desorption.

PubMed

Duan, Jun; Liu, Wen; Zhao, Xiao; Han, Yuling; O'Reilly, S E; Zhao, Dongye

2018-03-15

The 2010 Deepwater Horizon (DwH) oil spill contaminated ~1,773km of the Gulf of Mexico shorelines. Yet, few field data are available on the long-term fate and persistency of sediment-retained oil. While an unprecedented amount of oil dispersants was applied, the effects of oil dispersants on desorption of field aged oil remain unknown. This study aimed to investigate the abundance, distributions and physico-chemical availability of the oil retained in Bay Jimmy sediment, Louisiana, five years after the DwH oil spill, and to determine the effects of two model oil dispersants on the desorption potential of the residual oil. Total petroleum hydrocarbons (TPHs), n-alkanes and polycyclic aromatic hydrocarbons (PAHs) in the sediment were analyzed and compared with those in the crude oil and the pre-DwH levels, and batch desorption kinetic tests were carried out to quantify the dispersant effects on the desorption rate and extent. The biomarker hopanes profile and diagnostic ratio were analyzed, which confirmed the origin and persistence of the sediment-retained oil. After five-year natural weathering, the oil level in the sediment remained orders of magnitude higher than the pre-spill level. Nearly all low-molecular-weight n-alkanes and 2-ring PAHs had been degraded. Oil dispersants, SPC 1000 and Corexit EC9500A, were able to enhance solubilization of the sediment-retained oil upon resuspension of the sediment. Successive desorption experiments indicated that 71.6% of TPHs, 74.8% of n-alkanes, and 91.9% of PAHs in the sediment remained highly stable and hardly desorbable by seawater; yet, addition of 18mg/L of SPC 1000 enhanced the desorption and lowered these fractions to 57.3%, 68.1%, and 81.4%, respectively. The findings are important for understanding the natural weathering rate and persistence of oil residual and the effects of dispersants on the physical and biological availabilities of aged oil in coastal sediments. Copyright © 2017 Elsevier B.V. All rights

Dispersants have limited effects on exposure rates of oil spills on fish eggs and larvae in shelf seas.

PubMed

Vikebø, Frode B; Rønningen, Petter; Meier, Sonnich; Grøsvik, Bjørn Einar; Lien, Vidar S

2015-05-19

Early life stages of fish are particularly vulnerable to oil spills. Simulations of overlap of fish eggs and larvae with oil from different oil-spill scenarios, both without and with the dispersant Corexit 9500, enable quantitative comparisons of dispersants as a mitigation alternative. We have used model simulations of a blow out of 4500 m(3) of crude oil per day (Statfjord light crude) for 30 days at three locations along the Norwegian coast. Eggs were released from nine different known spawning grounds, in the period from March 1st until the end of April, and all spawning products were followed for 90 days from the spill start at April first independent of time for spawning. We have modeled overlap between spawning products and oil concentrations giving a total polycyclic hydrocarbon (TPAH) concentration of more than 1.0 or 0.1 ppb (μg/l). At these orders of magnitude, we expect acute mortality or sublethal effects, respectively. In general, adding dispersants results in higher concentrations of TPAHs in a reduced volume of water compared to not adding dispersants. Also, the TPAHs are displaced deeper in the water column. Model simulations of the spill scenarios showed that addition of chemical dispersant in general moderately decreased the fraction of eggs and larvae that were exposed above the selected threshold values.

Decrease in osmotically driven water flux and transport through mangrove roots after oil spills in the presence and absence of dispersants.

PubMed

Tansel, Berrin; Arreaza, Ariadna; Tansel, Derya Z; Lee, Mengshan

2015-09-15

The objective of this study was to evaluate the effect of crude oil on water transport through mangroves roots in the presence and absence of dispersants. Water transport through the roots were evaluated experimentally using red mangrove root segments exposed to salt water contaminated with Louisiana crude oil for seven days in the presence and absence of Corexit 9500A (dispersant). Experimental observations were interpreted in view of the structural integrity and fouling phenomena observed on the epidermis and endodermis layers of the roots. The effects of oil on the radial water flux through the epidermis and endodermis were analyzed using a dual layer filtration model. Progression of fouling due to accumulation and penetration of the contaminants through the root layers were interpreted in relation to observed mangrove health (long and short term effects) reported in the literature. Copyright © 2015 Elsevier Ltd. All rights reserved.

Ophthalmic effects of petroleum dispersant exposure on common murres (Uria aalge): An experimental study.

PubMed

Fiorello, Christine V; Freeman, Kate; Elias, Becky A; Whitmer, Emily; Ziccardi, Michael H

2016-12-15

The safety of chemical dispersants used during oil spill responses is largely unknown in birds. We captured common murres in Monterey Bay, CA and exposed them to Corexit EC9500a, crude oil, or a combination in artificial seawater. We performed ophthalmic examinations and measured intraocular pressures and tear production before and after exposure. Loglinear analysis found that exposure to oil or dispersant was related to the development of conjunctivitis and corneal ulcers. Odds ratios for birds exposed to oil or dispersant were positive and significant for the development of conjunctivitis, while odds ratios for the development of corneal ulcers were positive and significant only for birds exposed to a high concentration of oil. Ocular exposure to dispersants and petroleum in seabirds may cause conjunctivitis and may play a role in the development of corneal ulcers. These results have implications for policymakers who develop protocols for the use of dispersants during marine oil spills. Copyright © 2016 Elsevier Ltd. All rights reserved.

Dynamics of Heterocapsa sp. and the associated attached and free-living bacteria under the influence of dispersed and undispersed crude oil.

PubMed

Severin, T; Bacosa, H P; Sato, A; Erdner, D L

2016-12-01

While many studies have examined the impact of oil on phytoplankton or bacteria, very few considered the effects on the biological complex formed by phytoplankton and their associated phytoplankton-attached (PA) and free-living (FL) bacteria. However, associated bacteria can affect the physiology of phytoplankton and influence their stress responses. In this study, we monitored the growth of Heterocapsa sp., an armoured dinoflagellate, exposed to crude oil, Corexit dispersant, or both. Growth of Heterocapsa sp. is unaffected by crude oil up to 25 ppm, a concentration similar to the lower range measured on Florida beaches after the Deepwater Horizon oil spill. The PA bacteria community was resistant to exposure, whereas the FL community shifted towards oil degraders; both responses could contribute to Heterocapsa sp. oil resistance. The growth rate of Heterocapsa sp. decreased significantly only when exposed to dispersed oil at 25 ppm, indicating a synergistic effect of dispersant on oil toxicity in this organism. For the first time, we demonstrated the decoupling of the responses of the PA and FL bacteria communities after exposure to an environmental stress, in this case oil and dispersant. Our findings suggest new directions to explore in the understanding of interactions between unicellular eukaryotes and prokaryotes. In the environment, oil spills have the capacity to modify phytoplankton communities, with important consequences on the food web and the carbon cycle. We are just beginning to understand the oil resistance of phytoplankton species, making it difficult to predict community response. In this study we highlighted the strong resistance of Heterocapsa sp. to oil, which could be associated with its resilient attached bacteria and oil degradation by the free-living bacteria. This finding suggests new directions to explore in the understanding of oil impacts and interactions between eukaryotic and prokaryotic microbes. © 2016 The Society for Applied

Dispersants as Used in Response to the MC252-Spill Lead to Higher Mobility of Polycyclic Aromatic Hydrocarbons in Oil-Contaminated Gulf of Mexico Sand

PubMed Central

Zuijdgeest, Alissa; Huettel, Markus

2012-01-01

After the explosion of the Deepwater Horizon oil rig, large volumes of crude oil were washed onto and embedded in the sandy beaches and sublittoral sands of the Northern Gulf of Mexico. Some of this oil was mechanically or chemically dispersed before reaching the shore. With a set of laboratory-column experiments we show that the addition of chemical dispersants (Corexit 9500A) increases the mobility of polycyclic aromatic hydrocarbons (PAHs) in saturated permeable sediments by up to two orders of magnitude. Distribution and concentrations of PAHs, measured in the solid phase and effluent water of the columns using GC/MS, revealed that the mobility of the PAHs depended on their hydrophobicity and was species specific also in the presence of dispersant. Deepest penetration was observed for acenaphthylene and phenanthrene. Flushing of the columns with seawater after percolation of the oiled water resulted in enhanced movement by remobilization of retained PAHs. An in-situ benthic chamber experiment demonstrated that aromatic hydrocarbons are transported into permeable sublittoral sediment, emphasizing the relevance of our laboratory column experiments in natural settings. We conclude that the addition of dispersants permits crude oil components to penetrate faster and deeper into permeable saturated sands, where anaerobic conditions may slow degradation of these compounds, thus extending the persistence of potentially harmful PAHs in the marine environment. Application of dispersants in nearshore oil spills should take into account enhanced penetration depths into saturated sands as this may entail potential threats to the groundwater. PMID:23209777

Attachment of a hydrophobically modified biopolymer at the oil-water interface in the treatment of oil spills.

PubMed

Venkataraman, Pradeep; Tang, Jingjian; Frenkel, Etham; McPherson, Gary L; He, Jibao; Raghavan, Srinivasa R; Kolesnichenko, Vladimir; Bose, Arijit; John, Vijay T

2013-05-01

The stability of crude oil droplets formed by adding chemical dispersants can be considerably enhanced by the use of the biopolymer, hydrophobically modified chitosan. Turbidimetric analyses show that emulsions of crude oil in saline water prepared using a combination of the biopolymer and the well-studied chemical dispersant (Corexit 9500A) remain stable for extended periods in comparison to emulsions stabilized by the dispersant alone. We hypothesize that the hydrophobic residues from the polymer preferentially anchor in the oil droplets, thereby forming a layer of the polymer around the droplets. The enhanced stability of the droplets is due to the polymer layer providing an increase in electrostatic and steric repulsions and thereby a large barrier to droplet coalescence. Our results show that the addition of hydrophobically modified chitosan following the application of chemical dispersant to an oil spill can potentially reduce the use of chemical dispersants. Increasing the molecular weight of the biopolymer changes the rheological properties of the oil-in-water emulsion to that of a weak gel. The ability of the biopolymer to tether the oil droplets in a gel-like matrix has potential applications in the immobilization of surface oil spills for enhanced removal.

Biodegradation of dispersed oil in seawater is not inhibited by a commercial oil spill dispersant.

PubMed

Brakstad, Odd G; Ribicic, Deni; Winkler, Anika; Netzer, Roman

2018-04-01

Chemical dispersants are well-established as oil spill response tools. Several studies have emphasized their positive effects on oil biodegradation, but recent studies have claimed that dispersants may actually inhibit the oil biodegradation process. In this study, biodegradation of oil dispersions in natural seawater at low temperature (5°C) was compared, using oil without dispersant, and oil premixed with different concentrations of Slickgone NS, a widely used oil spill dispersant in Europe. Saturates (nC10-nC36 alkanes), naphthalenes and 2- to 5-ring polycyclic aromatic hydrocarbons (PAH) were biotransformed at comparable rates in all dispersions, both with and without dispersant. Microbial communities differed primarily between samples with or without oil, and they were not significantly affected by increasing dispersant concentrations. Our data therefore showed that a common oil spill dispersant did not inhibit biodegradation of oil at dispersant concentrations relevant for response operations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Bubble bursting as an aerosol generation mechanism during an oil spill in the deep-sea environment: molecular dynamics simulations of oil alkanes and dispersants in atmospheric air/salt water interfaces.

PubMed

Liyana-Arachchi, Thilanga P; Zhang, Zenghui; Ehrenhauser, Franz S; Avij, Paria; Valsaraj, Kalliat T; Hung, Francisco R

2014-01-01

Potential of mean force (PMF) calculations and molecular dynamics (MD) simulations were performed to investigate the properties of oil n-alkanes [i.e., n-pentadecane (C15), n-icosane (C20) and n-triacontane (C30)], as well as several surfactant species [i.e., the standard anionic surfactant sodium dodecyl sulfate (SDS), and three model dispersants similar to the Tween and Span species present in Corexit 9500A] at air/salt water interfaces. This study was motivated by the 2010 Deepwater Horizon (DWH) oil spill, and our simulation results show that, from the thermodynamic point of view, the n-alkanes and the model dispersants have a strong preference to remain at the air/salt water interface, as indicated by the presence of deep free energy minima at these interfaces. The free energy minimum of these n-alkanes becomes deeper as their chain length increases, and as the concentration of surfactant species at the interface increases. The n-alkanes tend to adopt a flat orientation and form aggregates at the bare air/salt water interface. When this interface is coated with surfactants, the n-alkanes tend to adopt more tilted orientations with respect to the vector normal to the interface. These simulation results are consistent with the experimental findings reported in the accompanying paper [Ehrenhauser et al., Environ. Sci.: Processes Impacts 2013, in press, (DOI: 10.1039/c3em00390f)]. The fact that these long-chain n-alkanes show a strong thermodynamic preference to remain at the air/salt water interfaces, especially if these interfaces are coated with surfactants, makes these species very likely to adsorb at the surface of bubbles or droplets and be ejected to the atmosphere by sea surface processes such as whitecaps (breaking waves) and bubble bursting. Finally, the experimental finding that more oil hydrocarbons are ejected when Corexit 9500A is present in the system is consistent with the deeper free energy minima observed for the n-alkanes at the air/salt water

Toxicity testing of crude oil and related compounds using early life stages of the crimson-spotted rainbowfish (Melanotaenia fluviatilis).

PubMed

Pollino, Carmel A; Holdway, Douglas A

2002-07-01

The toxicity of petroleum hydrocarbons to marine aquatic organisms has been widely investigated; however, the effects on freshwater environments have largely been ignored. In the Australian freshwater environment, the potential impacts of petroleum hydrocarbons are virtually unknown. The toxicity of crude oil and related compounds were measured in the sensitive early life stages of the crimson-spotted rainbowfish (Melanotaenia fluviatilis). Waterborne petroleum hydrocarbons crossed the chorion of embryonic rainbowfish, reducing survival and hatchability. Acute exposures resulted in developmental abnormalities at and above 0.5 mg/L total petroleum hydrocarbons (TPH). Deformities included pericardial edema, disturbed axis formation, and abnormal jaw development. When assessing the acute toxicities of the water-accommodated fraction (WAF) of crude oil, dispersants, dispersant-oil mixtures, and naphthalene to larval rainbowfish, the lowest to highest 96-h median lethal concentrations for day of hatch larvae were naphthalene (0.51 mg/L), dispersed crude oil WAF (DCWAF)-9527 (0.74 mg/L TPH), WAF (1.28 mg/L TPH), DCWAF-9500 (1.37 mg/L TPH), Corexit 9500 (14.5 mg/L TPH), and Corexit 9527 (20.1 mg/L). Using naphthalene as a reference toxicant, no differences were found between the sensitivities of larval rainbowfish collected from adults exposed to petroleum hydrocarbons during embryonic development and those collected from unexposed adults.

Oral treatment of Fischer 344 rats with weathered crude oil and a dispersant influences intestinal metabolism and microbiota.

PubMed

George, S E; Nelson, G M; Kohan, M J; Warren, S H; Eischen, B T; Brooks, L R

2001-06-22

When oil is spilled into aquatic systems, chemical dispersants frequently are applied to enhance emulsification and biological availability. In this study, a mammalian model system was used to determine the effect of Bonnie Light Nigerian crude oil, weathered for 2 d with continuous spraying and recirculation, and a widely used dispersant, Corexit (Cx) 9527, on intestinal microbial metabolism and associated populations. To determine the subchronic dose, concentrated or diluted (1:2, 1:5, 1:10, 1:20) Cx9527 or oil was administered by gavage to Fischer 344 rats and the effect on body weight was determined. Next, rats were treated for 5 wk with oil, dispersant, or dispersant + oil. Body and tissue weights, urine mutagenicity, and the impact on the intestinal microflora and three microbial intestinal enzymes linked to bioactivation were determined in the small and large intestines and cecum. Two tested dispersants, Cx9527 and Cx9500, were toxic in vitro (1:1,000 dilution), and oil was not mutagenic in strains TA98 and TA100(+/-S9). None of the treated rats produced urine mutagens detected by TA98 or TA100. Undiluted dispersant was lethal to rats, and weight changes were observed depending on the dilution, whereas oil generally was not toxic. In the 5-wk study, body and tissue weights were unaffected at the doses administered. Small-intestinal levels of azoreductase (AR), beta-glucuronidase (BG), and nitroreductase (NR) were considerably lower than cecal and large-intestinal activities at the same time point. A temporal increase in AR activity was observed in control animals in the 3 tissues examined, and large-intestinal BG activity was elevated in 3-wk controls. No significant changes in cecal BG activity were observed. Oil- or dispersant-treated rats had mixed results with reduced activity at 3 wk and elevated activity at 5 wk compared to controls. However, when the dispersant was combined with oil at 3 wk, a reduction in activity was observed that was similar to

Oil Droplet Size Distribution and Optical Properties During Wave Tank Simulated Oil Spills

NASA Astrophysics Data System (ADS)

Conmy, R. N.; Venosa, A.; Courtenay, S.; King, T.; Robinson, B.; Ryan, S.

2013-12-01

Fate and transport of spilled petroleum oils in aquatic environments is highly dependent upon oil droplet behavior which is a function of chemical composition, dispersibility (natural and chemically-enhanced) and droplet size distribution (DSD) of the oil. DSD is influenced by mixing energy, temperature, salinity, pressure, presence of dissolved and particulate materials, flow rate of release, and application of dispersants. To better understand DSD and droplet behavior under varying physical conditions, flask-scale experiments are often insufficient. Rather, wave tank simulations allow for scaling to field conditions. Presented here are experiment results from the Bedford Institute of Oceanography wave tank facility, where chemically-dispersed (Corexit 9500; DOR = 1:20) Louisiana Sweet crude, IFO-120 and ANS crude oil were exposed to mixing energies to achieve dispersant effectiveness observed in the field. Oil plumes were simulated, both surface and subsea releases with varying water temperature and flow rate. Fluorometers (Chelsea Technologies Group AQUATracka, Turner Designs Cyclops, WET Labs Inc ECO) and particle size analyzers (Sequoia LISST) were used to track the dispersed plumes in the tank and characterize oil droplets. Sensors were validated with known oil volumes (down to 300 ppb) and measured Total Petroleum Hydrocarbons (TPH) and Benzene-Toluene-Ethylbenzene-Xylene (BTEX) values. This work has large implications for tracking surface and deep sea oil plumes with fluorescence and particle size analyzers, improved weathering and biodegradation estimates, and understanding the fate and transport of spill oil.

Comparative toxicity of oil, dispersant, and oil plus dispersant to several marine species.

PubMed

Fuller, Chris; Bonner, James; Page, Cheryl; Ernest, Andrew; McDonald, Thomas; McDonald, Susanne

2004-12-01

Dispersants are a preapproved chemical response agent for oil spills off portions of the U.S. coastline, including the Texas-Louisiana coast. However, questions persist regarding potential environmental risks of dispersant applications in nearshore regions (within three nautical miles of the shoreline) that support dense populations of marine organisms and are prone to spills resulting from human activities. To address these questions, a study was conducted to evaluate the relative toxicity of test media prepared with dispersant, weathered crude oil, and weathered crude oil plus dispersant. Two fish species, Cyprinodon variegatus and Menidia beryllina, and one shrimp species, Americamysis bahia (formerly Mysidopsis bahia), were used to evaluate the relative toxicity of the different media under declining and continuous exposure regimes. Microbial toxicity was evaluated using the luminescent bacteria Vibrio fisheri. The data suggested that oil media prepared with a chemical dispersant was equal to or less toxic than the oil-only test medium. Data also indicated that continuous exposures to the test media were generally more toxic than declining exposures. The toxicity of unweathered crude oil with and without dispersant was also evaluated using Menidia beryllina under declining exposure conditions. Unweathered oil-only media were dominated by soluble hydrocarbon fractions and found to be more toxic than weathered oil-only media in which colloidal oil fractions dominated. Total concentrations of petroleum hydrocarbons in oil-plus-dispersant media prepared with weathered and unweathered crude oil were both dominated by colloidal oil and showed no significant difference in toxicity. Analysis of the toxicity data suggests that the observed toxicity was a function of the soluble crude oil components and not the colloidal oil.

Effectiveness and potential ecological effects of offshore surface dispersant use during the Deepwater Horizon oil spill: a retrospective analysis of monitoring data.

PubMed

Bejarano, Adriana C; Levine, Edwin; Mearns, Alan J

2013-12-01

The Special Monitoring of Applied Response Technologies (SMART) program was used during the Deepwater Horizon oil spill as a strategy to monitor the effectiveness of sea surface dispersant use. Although SMART was implemented during aerial and vessel dispersant applications, this analysis centers on the effort of a special dispersant missions onboard the M/V International Peace, which evaluated the effectiveness of surface dispersant applications by vessel only. Water samples (n = 120) were collected from background sites, and under naturally and chemically dispersed oil slicks, and were analyzed for polycyclic aromatic hydrocarbons (TPAHs), total petroleum hydrocarbons (TPH), and a chemical marker of Corexit (dipropylene glycol n-butyl ether, DPnB). Water chemistry results were analyzed relative to SMART field assessments of dispersant effectiveness ("not effective," "effective," and "very effective"), based on in situ fluorometry. Chemistry data were also used to indirectly determine if the use of dispersants increased the risk of acute effects to water column biota, by comparison to toxicity benchmarks. TPAH and TPH concentrations in background, and naturally and chemically dispersed samples were extremely variable, and differences were not statistically detected across sample types. Ratios of TPAH and TPH between chemically and naturally dispersed samples provided a quantitative measure of dispersant effectiveness over natural oil dispersion alone, and were in reasonable agreement with SMART field assessments of dispersant effectiveness. Samples from "effective" and "very effective" dispersant applications had ratios of TPAH and TPH up to 35 and 64, respectively. In two samples from an "effective" dispersant application, TPHs and TPAHs exceeded acute benchmarks (0.81 mg/L and 8 μg/L, respectively), while none exceeded DPnB's chronic value (1,000 μg/L). Although the primary goal of the SMART program is to provide near real-time effectiveness data to the

Effect of Dispersants on the Biodegradation of South ...

EPA Pesticide Factsheets

This article reports biodegradation rates for a commercial dispersant, JD-2000, South Louisiana crude oil (SLC) alone, and SLC dispersed with JD-2000 at 5 and 25oC. Results from the biodegradation experiments revealed that Component X, a chemical marker for JD-2000, rapidly degraded at both temperatures. The application of JD-2000 decreased by half the overall biodegradation rate of aliphatic compounds at 25oC. At 5oC, a residual fraction consisting of iso- and n-alkanes (C29-C35) persisted after 56 d. The combination of dispersant and higher temperature resulted in faster removal rates for 2- and 3-ring polycyclic aromatic hydrocarbons. When compared with Corexit 9500, our results suggest that the chemistry of the surfactant (or surfactants) in JD-2000 might have favored oil dissolution (substrate transport to the aqueous phase) as an uptake mechanism over adhesion, which requires direct contact of the biomass with the oil. This paper presents results obtained after carrying out treatability experiments with South Louisiana crude oil (SLC) and JD-2000, a dispersant included on the National Contingency Plan (NCP) Product Schedule. In a study conducted by Judson et al. (2010), JD-2000 was found to be significantly less cytotoxic than all other NCP-listed products. We also compare the results for JD-2000 with those obtained in a previous study for C9500 dispersing the same SLC oil (Campo et al., 2013).

The Deepwater Horizon Oil Spill: Ecogenomics of the Deep-Sea Plume

NASA Astrophysics Data System (ADS)

Hazen, T. C.

2012-12-01

The explosion on April 20, 2010 at the BP-leased Deepwater Horizon drilling rig in the Gulf of Mexico off the coast of Louisiana, resulted in oil and gas rising to the surface and the oil coming ashore in many parts of the Gulf, it also resulted in the dispersment of an immense oil plume 4,000 feet below the surface of the water. Despite spanning more than 600 feet in the water column and extending more than 10 miles from the wellhead, the dispersed oil plume was gone within weeks after the wellhead was capped - degraded and diluted to undetectable levels. Furthermore, this degradation took place without significant oxygen depletion. Ecogenomics enabled discovery of new and unclassified species of oil-eating bacteria that apparently lives in the deep Gulf where oil seeps are common. Using 16s microarrays, functional gene arrays, clone libraries, lipid analysis and a variety of hydrocarbon and micronutrient analyses we were able to characterize the oil degraders. Metagenomic sequence data was obtained for the deep-water samples using the Illumina platform. In addition, single cells were sorted and sequenced for the some of the most dominant bacteria that were represented in the oil plume; namely uncultivated representatives of Colwellia and Oceanospirillum. In addition, we performed laboratory microcosm experiments using uncontaminated water collected from The Gulf at the depth of the oil plume to which we added oil and COREXIT. These samples were characterized by 454 pyrotag. The results provide information about the key players and processes involved in degradation of oil, with and without COREXIT, in different impacted environments in The Gulf of Mexico. We are also extending these studies to explore dozens of deep sediment samples that were also collected after the oil spill around the wellhead. This data suggests that a great potential for intrinsic bioremediation of oil plumes exists in the deep-sea and other environs in the Gulf of Mexico.

Oil spill dispersants: boon or bane?

PubMed

Prince, Roger C

2015-06-02

Dispersants provide a reliable large-scale response to catastrophic oil spills that can be used when the preferable option of recapturing the oil cannot be achieved. By allowing even mild wave action to disperse floating oil into tiny droplets (<70 μm) in the water column, seabirds, reptiles, and mammals are protected from lethal oiling at the surface, and microbial biodegradation is dramatically increased. Recent work has clarified how dramatic this increase is likely to be: beached oil has an environmental residence of years, whereas dispersed oil has a half-life of weeks. Oil spill response operations endorse the concept of net environmental benefit, that any environmental costs imposed by a response technique must be outweighed by the likely benefits. This critical review discusses the potential environmental debits and credits from dispersant use and concludes that, in most cases, the potential environmental costs of adding these chemicals to a polluted area are likely outweighed by the much shorter residence time, and hence integrated environmental impact, of the spilled oil in the environment.

Investigating the effectiveness of the surfactant dioctyl sodium sulfosuccinate to disperse oil in a changing marine environment

NASA Astrophysics Data System (ADS)

Steffy, David A.; Nichols, Alfred C.; Kiplagat, George

2011-12-01

We investigated the surfactant dioctyl sodium sulfosuccinate (DOSS) and its delivery system Corexit 9500A, used to disperse oil released during the Gulf of Mexico spill during the summer of 2010. DOSS is an organic sulfonic acid salt that acts as a synthetic detergent and disrupts the interfacial tension between the salt water and crude oil phases. The disruption reaches a maximum at or above the critical micelle concentration (CMC). The CMC for the surfactant was determined to be 0.17% solution in deionized water at a pH of 7.2 and a temperature of 21.1 °C (70°F). The CMC is lower in salt water, at 0.125% solution. This has been identified as a "salting out" effect (Somasundaran, 2006). The CMC of DOSS in both saline and deionized water occurred at lower-percent solutions at higher temperatures. The surface tension versus concentration plots can be modeled using a power equation, with correlation coefficients consistently over 0.94. Surface tension versus concentration plots are scalable to fit the desired temperature by the function f(x) = (1/1+Xα), where α =T1/T2. Tests measured the stability of the DOSS micelles when exposed to a continuous UVA radiation. This photodegradation is directly related to the duration of exposure.

Identifying oil/marine snow associations in mesocosm simulations of the Deepwater Horizon oil spill event using solid-state 13C NMR spectroscopy.

PubMed

Hatcher, Patrick G; Obeid, Wassim; Wozniak, Andrew S; Xu, Chen; Zhang, Saijin; Santschi, Peter H; Quigg, Antonietta

2018-01-01

The Deepwater Horizon oil spill stimulated the release of marine snow made up of dead/living plankton/bacteria and their exopolymeric polysaccharide substances (EPS), termed marine oil snow (MOS), promoting rapid removal of oil from the water column into sediments near the well site. Mesocosm simulations showed that Macondo surrogate oil readily associates with the marine snow. Quantitative solid-state 13 C NMR readily distinguishes this oil from naturally formed marine snow and reveals that adding the dispersant Corexit enhances the amount of oil associated with the MOS, thus contributing to rapid removal from the water column. Solvent extraction of MOS removes the oil-derived compounds for analysis by one and two-dimensional GC/MS and evaluation of potential transformations they undergo when associated with the EPS. The results reveal that the oil associated with EPS is subjected to rapid transformation, in a matter of days, presumably by bacteria and fungi associated with EPS. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evaluation of new aquatic toxicity test methods for oil dispersants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pace, C.B.; Clark, J.R.; Bragin, G.E.

1994-12-31

Current aquatic toxicity test methods used for dispersant registration do not address real world exposure scenarios. Current test methods require 48 or 96 hour constant exposure conditions. In contrast, environmentally realistic exposures can be described as a pulse in which the initial concentration declines over time. Recent research using a specially designed testing apparatus (the California system) has demonstrated that exposure to Corexit 9527{reg_sign} under pulsed exposure conditions may be 3 to 22 times less toxic compared to continuous exposure scenarios. The objectives of this study were to compare results of toxicity tests using the California test system to resultsmore » from standardized tests, evaluate sensitivity of regional (Holmesimysis cast and Atherinops affinis) vs. standard test species (Mysidopsis bahia and Menidia beryllina) and determine if tests using the California test system and method are reproducible. All tests were conducted using Corexit 9527{reg_sign} as the test material. Standard toxicity tests conducted with M. bahia and H. cast resulted in LC50s similar to those from tests using the California apparatus. LC50s from tests conducted in the authors` laboratory with the California system and standard test species were within a factor of 2 to 6 of data previously reported for west coast species. Results of tests conducted with H. cast in the laboratory compared favorably to data reported by Singer et al. 1991.« less

DISPERSANT EFFECTIVENESS ON OIL SPILLS - EMPIRICAL CORRELATIONS

EPA Science Inventory

When a dispersant is applied to an oil slick, its effectiveness in dispersing the spilled oil depends on various factors such as oil properties, wave mixing energy, temperature of both oil and water, and salinity of the water. Estuaries represent water with varying salinities. In...

Toxicities of oils, dispersants and dispersed oils to algae and aquatic plants: review and database value to resource sustainability

EPA Science Inventory

Published toxicity results are reviewed for oils, dispersants and dispersed oils and aquatic plants. The historical phytotoxicity database consists largely of results from a patchwork of research conducted after oil spills to marine waters. Toxicity information is available for ...

Dispersibility and biotransformation of oils with different properties in seawater.

PubMed

Brakstad, Odd G; Farooq, Umer; Ribicic, Deni; Netzer, Roman

2018-01-01

Dispersants are used to remove oils slicks from sea surfaces and to generate small oil-droplet dispersions, which may result in enhanced biodegradation of the oil. In this study, dispersibility and biodegradation of chemically dispersed oils with different physical-chemical properties (paraffinic, naphthenic and asphaltenic oils) were compared in natural temperate SW at 13 °C. All selected oils were chemically dispersible when well-known commercial dispersants were used. However, interfacial tension (IFT) studies of the dispersed oils showed different IFT properties of the oils at 13 °C, and also different leaching of the dispersants from oil droplet surfaces. Biodegradation studies of the chemically dispersed oils were performed in a carousel system, with initial median droplet sizes <30 μm and oil concentrations of 2.5-2.8 mg/L. During biodegradation, oil droplet concentrations were rapidly reduced, in association with the emergence of macroscopic 'flocs'. Biotransformation results showed that half-lives of semivolatile total extractable organic carbon (TEOC), single target 2- to 4-ring PAH, and 22 oil compound groups used as input data in the oil spill contingency model OSCAR, did not differ significantly between the oils (P > 0.05), while n-alkanes half-lives differed significantly (P < 0.05). Biotransformation was associated with rapid microbial growth in all oil dispersions, in association with n-alkane and PAH biotransformation. These results have implications for the predictions of biodegradation of oil slicks treated with dispersants in temperate SW. Copyright © 2017 Elsevier Ltd. All rights reserved.

Determination of the anionic surfactant di(ethylhexyl) sodium sulfosuccinate in water samples collected from Gulf of Mexico coastal waters before and after landfall of oil from the Deepwater Horizon oil spill, May to October, 2010

USGS Publications Warehouse

Gray, James L.; Kanagy, Leslie K.; Furlong, Edward T.; McCoy, Jeff W.; Kanagy, Chris J.

2011-01-01

On April 22, 2010, the explosion on and subsequent sinking of the Deepwater Horizon oil drilling platform resulted in the release of crude oil into the Gulf of Mexico. At least 4.4 million barrels had been released into the Gulf of Mexico through July 15, 2010, 10 to 29 percent of which was chemically dispersed, primarily using two dispersant formulations. Initially, the dispersant Corexit 9527 was used, and when existing stocks of that formulation were exhausted, Corexit 9500 was used. Over 1.8 million gallons of the two dispersants were applied in the first 3 months after the spill. This report presents the development of an analytical method to analyze one of the primary surfactant components of both Corexit formulations, di(ethylhexyl) sodium sulfosuccinate (DOSS), the preliminary results, and the associated quality assurance/quality control (QA/QC) from samples collected from various points on the Gulf Coast between Texas and Florida. Seventy water samples and 8 field QC samples were collected before the predicted landfall of oil (pre-landfall) on the Gulf Coast, and 51 water samples and 10 field QC samples after the oil made landfall (post-landfall). Samples were collected in Teflon(Registered) bottles and stored at -20(degrees)C until analysis. Extraction of whole-water samples used sorption onto a polytetrafluoroethylene (PTFE) filter to isolate DOSS, with subsequent 50 percent methanol/water elution of the combined dissolved and particulate DOSS fractions. High-performance liquid chromatography/tandem mass spectrometry (LC/MS/MS) was used to identify and quantify DOSS by the isotope dilution method, using a custom-synthesized 13C4-DOSS labeled standard. Because of the ubiquitous presence of DOSS in laboratory reagent water, a chromatographic column was installed in the LC/MS/MS between the system pumps and the sample injector that separated this ambient background DOSS contamination from the sample DOSS, minimizing one source of blank contamination

Effects of three types of oil dispersants on biodegradation of dispersed crude oil in water surrounding two Persian gulf provinces.

PubMed

Zolfaghari-Baghbaderani, Azadeh; Emtyazjoo, Mozhgan; Poursafa, Parinaz; Mehrabian, Sedigheh; Bijani, Samira; Farkhani, Daryoush; Mirmoghtadaee, Parisa

2012-01-01

To determine the most effective and biodegradable dispersant of spilled oil in water surrounding two Persian Gulf provinces. This study compared the effects of three dispersants, Pars 1, Pars 2, and Gamlen OD4000 on removal of oil in two Persian Gulf provinces' water. Overall, 16 stations were selected. Using the Well method, the growth rate of isolated bacteria and fungi was identified. To specify the growth rate of microorganisms and their usage of oil in the presence of the above-mentioned dispersants, as exclusive sources of carbon, the bacteria were grown in culture medium for 28 days at 120 rpm, 30°C, and their optical density was measured by spectrophotometry. Then, we tested biological oxygen demand (BOD) and chemical oxygen demand (COD) in microorganisms. The highest growth rate was documented for the growth of microorganisms on either Pars 1 or Pars 2 dispersants or their mixtures with oil. However, the culture having microorganisms grown on Pars 1 had higher BOD and COD than the other two dispersants (9200 and 16800 versus 500 and 960, P < 0.05). Mixture of oil and Pars 2 as well as oil and Pars 1 dispersants showed the highest BODs and CODs, respectively. In the Bahregan province, microorganisms grown on Pars 2 had maximum amount of BOD and COD in comparison with Pars 1 and Gamlen dispersants (7100 and 15200 versus 6000 and 10560, P < 0.05). Pars 1 and Pars 2 were the most effective dispersants with highest degradability comparing Gamlen. In each region, the most suitable compound for removing oil spill from offshores with least secondary contamination should be investigated.

Effects of Three Types of Oil Dispersants on Biodegradation of Dispersed Crude Oil in Water Surrounding Two Persian Gulf Provinces

PubMed Central

Zolfaghari-Baghbaderani, Azadeh; Emtyazjoo, Mozhgan; Poursafa, Parinaz; Mehrabian, Sedigheh; Bijani, Samira; Farkhani, Daryoush; Mirmoghtadaee, Parisa

2012-01-01

Objective. To determine the most effective and biodegradable dispersant of spilled oil in water surrounding two Persian Gulf provinces. Methods. This study compared the effects of three dispersants, Pars 1, Pars 2, and Gamlen OD4000 on removal of oil in two Persian Gulf provinces' water. Overall, 16 stations were selected. Using the Well method, the growth rate of isolated bacteria and fungi was identified. To specify the growth rate of microorganisms and their usage of oil in the presence of the above-mentioned dispersants, as exclusive sources of carbon, the bacteria were grown in culture medium for 28 days at 120 rpm, 30°C, and their optical density was measured by spectrophotometry. Then, we tested biological oxygen demand (BOD) and chemical oxygen demand (COD) in microorganisms. Results. The highest growth rate was documented for the growth of microorganisms on either Pars 1 or Pars 2 dispersants or their mixtures with oil. However, the culture having microorganisms grown on Pars 1 had higher BOD and COD than the other two dispersants (9200 and 16800 versus 500 and 960, P < 0.05). Mixture of oil and Pars 2 as well as oil and Pars 1 dispersants showed the highest BODs and CODs, respectively. In the Bahregan province, microorganisms grown on Pars 2 had maximum amount of BOD and COD in comparison with Pars 1 and Gamlen dispersants (7100 and 15200 versus 6000 and 10560, P < 0.05). Conclusion. Pars 1 and Pars 2 were the most effective dispersants with highest degradability comparing Gamlen. In each region, the most suitable compound for removing oil spill from offshores with least secondary contamination should be investigated. PMID:22363352

Interactions between Zooplankton and Crude Oil: Toxic Effects and Bioaccumulation of Polycyclic Aromatic Hydrocarbons

PubMed Central

Almeda, Rodrigo; Wambaugh, Zoe; Wang, Zucheng; Hyatt, Cammie; Liu, Zhanfei; Buskey, Edward J.

2013-01-01

We conducted ship-, shore- and laboratory-based crude oil exposure experiments to investigate (1) the effects of crude oil (Louisiana light sweet oil) on survival and bioaccumulation of polycyclic aromatic hydrocarbons (PAHs) in mesozooplankton communities, (2) the lethal effects of dispersant (Corexit 9500A) and dispersant-treated oil on mesozooplankton, (3) the influence of UVB radiation/sunlight exposure on the toxicity of dispersed crude oil to mesozooplankton, and (4) the role of marine protozoans on the sublethal effects of crude oil and in the bioaccumulation of PAHs in the copepod Acartia tonsa. Mortality of mesozooplankton increased with increasing oil concentration following a sigmoid model with a median lethal concentration of 32.4 µl L−1 in 16 h. At the ratio of dispersant to oil commonly used in the treatment of oil spills (i.e. 1∶20), dispersant (0.25 µl L−1) and dispersant- treated oil were 2.3 and 3.4 times more toxic, respectively, than crude oil alone (5 µl L−1) to mesozooplankton. UVB radiation increased the lethal effects of dispersed crude oil in mesozooplankton communities by 35%. We observed selective bioaccumulation of five PAHs, fluoranthene, phenanthrene, pyrene, chrysene and benzo[b]fluoranthene in both mesozooplankton communities and in the copepod A. tonsa. The presence of the protozoan Oxyrrhis marina reduced sublethal effects of oil on A. tonsa and was related to lower accumulations of PAHs in tissues and fecal pellets, suggesting that protozoa may be important in mitigating the harmful effects of crude oil exposure in copepods and the transfer of PAHs to higher trophic levels. Overall, our results indicate that the negative impact of oil spills on mesozooplankton may be increased by the use of chemical dispersant and UV radiation, but attenuated by crude oil-microbial food webs interactions, and that both mesozooplankton and protozoans may play an important role in fate of PAHs in marine environments. PMID:23840628

Logistics of Oil Spill Dispersant Application. Volume I. Logistics-Related Properties of Oil Spill Dispersants.

DOT National Transportation Integrated Search

1982-11-01

The use of chemicals for oil spill dispersal, while not presently widespread in the U.S., would have implications for the U.S. Coast Guard's Marine Environmental Protection program. This report explores the logistics of oil disperant application by t...

Large Scale Behavior and Droplet Size Distributions in Crude Oil Jets and Plumes

NASA Astrophysics Data System (ADS)

Katz, Joseph; Murphy, David; Morra, David

2013-11-01

The 2010 Deepwater Horizon blowout introduced several million barrels of crude oil into the Gulf of Mexico. Injected initially as a turbulent jet containing crude oil and gas, the spill caused formation of a subsurface plume stretching for tens of miles. The behavior of such buoyant multiphase plumes depends on several factors, such as the oil droplet and bubble size distributions, current speed, and ambient stratification. While large droplets quickly rise to the surface, fine ones together with entrained seawater form intrusion layers. Many elements of the physics of droplet formation by an immiscible turbulent jet and their resulting size distribution have not been elucidated, but are known to be significantly influenced by the addition of dispersants, which vary the Weber Number by orders of magnitude. We present experimental high speed visualizations of turbulent jets of sweet petroleum crude oil (MC 252) premixed with Corexit 9500A dispersant at various dispersant to oil ratios. Observations were conducted in a 0.9 m × 0.9 m × 2.5 m towing tank, where large-scale behavior of the jet, both stationary and towed at various speeds to simulate cross-flow, have been recorded at high speed. Preliminary data on oil droplet size and spatial distributions were also measured using a videoscope and pulsed light sheet. Sponsored by Gulf of Mexico Research Initiative (GoMRI).

DISPERSANT EFFECTIVENESS ON OIL SPILLS - IMPACT OF ENVIRONMENTAL FACTORS

EPA Science Inventory

When a dispersant is applied to an oil slick, its effectiveness in dispersing the spilled oil depends on various factors such as oil properties, wave mixing energy, temperature of both oil and water, and salinity of the water. Estuaries represent water with varying salinities. In...

Comparative Toxicity of Eight Oil Dispersants, Louisiana Sweet Crude Oil (LSC) and Chemically Dispersed LSC to Two Aquatic Test Species

EPA Science Inventory

This study describes the acute toxicity of eight commercial oil dispersants, Louisiana sweet crude oil (LSC), and chemically dispersed LSC. The approach utilized consistent test methodologies within a single laboratory in assessing the relative acute toxicity of the eight dispers...

DISPERSANT EFFECTIVENESS ON THREE OILS UNDER VARIOUS SIMULATED ENVIRONMENTAL CONDITIONS

EPA Science Inventory

The complexity of chemical and physical interactions between spilled oils, dispersants and the sea, necessitates an empirical approach for describing the interaction between the dispersant and oil slick which may provide a guide to dispersant effects on oil slicks. Recently, US ...

Effects of COREXIT (registered trademark) EC9500A on Bacteria from a Beach Oiled by the Deepwater Horizon Spill

DTIC Science & Technology

2011-01-01

AQUATIC MICROBIAL ECOLOGY Aquat Microb Ecol Vol. 63: 101–109, 2011 doi: 10.3354/ame01482 Published online March 31 INTRODUCTION The mobile offshore...toxicity tests confirm that COREXIT® EC9500A does not pose a significant threat to invertebrate and adult fish pop- ulations, there is limited information on...Deepwater Horizon incident. Although toxicity tests confirm that COREXIT? EC9500A does not pose a significant threat to invertebrate and adult fish

MODELING DISPERSANT INTERACTIONS WITH OIL SPILLS

EPA Science Inventory

EPA is developing a model called the EPA Research Object-Oriented Oil Spill Model (ERO3S) and associated databases to simulate the impacts of dispersants on oil slicks. Because there are features of oil slicks that align naturally with major concepts of object-oriented programmi...

The enhanced stability and biodegradation of dispersed crude oil droplets by Xanthan Gum as an additive of chemical dispersant.

PubMed

Wang, Aiqin; Li, Yiming; Yang, Xiaolong; Bao, Mutai; Cheng, Hua

2017-05-15

It is necessary for chemical dispersant to disperse oil effectively and maintain the stability of oil droplets. In this work, Xanthan Gum (XG) was used as an environmentally friendly additive in oil dispersant formulation to enhance the stability and biodegradation of dispersed crude oil droplets. When XG was used together with chemical dispersant 9500A, the dispersion effectiveness of crude oil in artificial sea water (ASW) and the oil droplet stability were both greatly enhanced. In the presence of XG, lower concentration of 9500A was needed to achieve the effective dispersion and stabilization. In addition to the enhancement of dispersion and stabilization, it was found that the biodegradation rate of crude oil by bacteria was dramatically enhanced when a mixture of 9500A and XG was used as a dispersant. Because of the low environmental impact of XG, this would be a potential way to formulate the dispersant with lower toxicity. Copyright © 2017 Elsevier Ltd. All rights reserved.

USE OF CHEMICAL DISPERSANTS FOR MARINE OIL SPILLS

EPA Science Inventory

Chemical dispersants are one of the tools available to oil spill response personnel to control the spread of an oil slick. The manual presents information from the literature relative to dispersant effectiveness, toxicity and other environmental factors, regulatory and administra...

Dispersed oil disrupts microbial pathways in pelagic food webs.

PubMed

Ortmann, Alice C; Anders, Jennifer; Shelton, Naomi; Gong, Limin; Moss, Anthony G; Condon, Robert H

2012-01-01

Most of the studies of microbial processes in response to the Deepwater Horizon oil spill focused on the deep water plume, and not on the surface communities. The effects of the crude oil and the application of dispersants on the coastal microbial food web in the northern Gulf of Mexico have not been well characterized even though these regions support much of the fisheries production in the Gulf. A mesocosm experiment was carried out to determine how the microbial community off the coast of Alabama may have responded to the influx of surface oil and dispersants. While the addition of glucose or oil alone resulted in an increase in the biomass of ciliates, suggesting transfer of carbon to higher trophic levels was likely; a different effect was seen in the presence of dispersant. The addition of dispersant or dispersed oil resulted in an increase in the biomass of heterotrophic prokaryotes, but a significant inhibition of ciliates, suggesting a reduction in grazing and decrease in transfer of carbon to higher trophic levels. Similar patterns were observed in two separate experiments with different starting nutrient regimes and microbial communities suggesting that the addition of dispersant and dispersed oil to the northern Gulf of Mexico waters in 2010 may have reduced the flow of carbon to higher trophic levels, leading to a decrease in the production of zooplankton and fish on the Alabama shelf.

An Oil/Water disperser device for use in an oil content Monitor/Control system

NASA Astrophysics Data System (ADS)

Kempel, F. D.

1985-07-01

This patent application discloses an oil content monitor/control unit system, including an oil/water disperser device, which is configured to automatically monitor and control processed effluent from an associated oil/water separator so that if the processed effluent exceeds predetermine in-port or at-sea oil concentration lmits, it is either recirculated to an associated oil/water separator via a ship's bilge for additional processing, or diverted to a holding tank for storage. On the other hand, if the oil concentration of the processed effluent is less than predetermine in-port or at-sea limits, it is discharged overboard. The oil/water disperser device is configured to break up any oil present in the processed effluent into uniform droplets for more accurate sensing of the oil present in the processed effluent into uniform droplets for more accurate sensing of the oil-in-water concentration level thereof. The oil/water disperser device has a flow-actuated variable orifice configured into a spring-loaded polyethylene plunger which provides the uniform distribution of oil droplets.

Sensitivity of the deep-sea amphipod Eurythenes gryllus to chemically dispersed oil.

PubMed

Olsen, Gro Harlaug; Coquillé, Nathalie; Le Floch, Stephane; Geraudie, Perrine; Dussauze, Matthieu; Lemaire, Philippe; Camus, Lionel

2016-04-01

In the context of an oil spill accident and the following oil spill response, much attention is given to the use of dispersants. Dispersants are used to disperse an oil slick from the sea surface into the water column generating a cloud of dispersed oil droplets. The main consequence is an increasing of the sea water-oil interface which induces an increase of the oil biodegradation. Hence, the use of dispersants can be effective in preventing oiling of sensitive coastal environments. Also, in case of an oil blowout from the seabed, subsea injection of dispersants may offer some benefits compared to containment and recovery of the oil or in situ burning operation at the sea surface. However, biological effects of dispersed oil are poorly understood for deep-sea species. Most effects studies on dispersed oil and also other oil-related compounds have been focusing on more shallow water species. This is the first approach to assess the sensitivity of a macro-benthic deep-sea organism to dispersed oil. This paper describes a toxicity test which was performed on the macro-benthic deep-sea amphipod (Eurythenes gryllus) to determine the concentration causing lethality to 50% of test individuals (LC50) after an exposure to dispersed Brut Arabian Light (BAL) oil. The LC50 (24 h) was 101 and 24 mg L(-1) after 72 h and 12 mg L(-1) at 96 h. Based on EPA scale of toxicity categories to aquatic organisms, an LC50 (96 h) of 12 mg L(-1) indicates that the dispersed oil was slightly to moderately toxic to E. gryllus. As an attempt to compare our results to others, a literature study was performed. Due to limited amount of data available for dispersed oil and amphipods, information on other crustacean species and other oil-related compounds was also collected. Only one study on dispersed oil and amphipods was found, the LC50 value in this study was similar to the LC50 value of E. gryllus in our study. Since toxicity data are important input to risk assessment and net environmental

Chemical dispersants can suppress the activity of natural oil-degrading microorganisms

PubMed Central

Kleindienst, Sara; Seidel, Michael; Ziervogel, Kai; Grim, Sharon; Loftis, Kathy; Harrison, Sarah; Malkin, Sairah Y.; Perkins, Matthew J.; Field, Jennifer; Sogin, Mitchell L.; Dittmar, Thorsten; Passow, Uta; Medeiros, Patricia M.; Joye, Samantha B.

2015-01-01

During the Deepwater Horizon oil well blowout in the Gulf of Mexico, the application of 7 million liters of chemical dispersants aimed to stimulate microbial crude oil degradation by increasing the bioavailability of oil compounds. However, the effects of dispersants on oil biodegradation rates are debated. In laboratory experiments, we simulated environmental conditions comparable to the hydrocarbon-rich, 1,100 m deep plume that formed during the Deepwater Horizon discharge. The presence of dispersant significantly altered the microbial community composition through selection for potential dispersant-degrading Colwellia, which also bloomed in situ in Gulf deep waters during the discharge. In contrast, oil addition to deepwater samples in the absence of dispersant stimulated growth of natural hydrocarbon-degrading Marinobacter. In these deepwater microcosm experiments, dispersants did not enhance heterotrophic microbial activity or hydrocarbon oxidation rates. An experiment with surface seawater from an anthropogenically derived oil slick corroborated the deepwater microcosm results as inhibition of hydrocarbon turnover was observed in the presence of dispersants, suggesting that the microcosm findings are broadly applicable across marine habitats. Extrapolating this comprehensive dataset to real world scenarios questions whether dispersants stimulate microbial oil degradation in deep ocean waters and instead highlights that dispersants can exert a negative effect on microbial hydrocarbon degradation rates. PMID:26553985

Effects of chemical dispersants and mineral fines on crude oil dispersion in a wave tank under breaking waves.

PubMed

Li, Zhengkai; Kepkay, Paul; Lee, Kenneth; King, Thomas; Boufadel, Michel C; Venosa, Albert D

2007-07-01

The interaction of chemical dispersants and suspended sediments with crude oil influences the fate and transport of oil spills in coastal waters. A wave tank study was conducted to investigate the effects of chemical dispersants and mineral fines on the dispersion of oil and the formation of oil-mineral-aggregates (OMAs) in natural seawater. Results of ultraviolet spectrofluorometry and gas chromatography flame ionized detection analysis indicated that dispersants and mineral fines, alone and in combination, enhanced the dispersion of oil into the water column. Measurements taken with a laser in situ scattering and transmissometer (LISST-100X) showed that the presence of mineral fines increased the total concentration of the suspended particles from 4 to 10microl l(-1), whereas the presence of dispersants decreased the particle size (mass mean diameter) of OMAs from 50 to 10microm. Observation with an epifluorescence microscope indicated that the presence of dispersants, mineral fines, or both in combination significantly increased the number of particles dispersed into the water.

DISPERSIBILITY OF CRUDE OIL IN FRESH WATER

EPA Science Inventory

The effects of surfactant composition on the ability of chemical dispersants to disperse crude oil in fresh water were investigated. The objective of this research was to determine whether effective fresh water dispersants can be designed in case this technology is ever consider...

EFFECTS OF CHEMICAL DISPERSANTS AND MINERAL FINES ON CRUDE OIL DISPERSION IN A WAVE TANK UNDER BREAKING WAVES

EPA Science Inventory

The interaction of chemical dispersants and suspended sediments with crude oil influences the fate and transport of oil spills in coastal waters. A wave tank study was conducted to investigate the effects of chemical dispersants and mineral fines on the dispersion of oil and the ...

Molecular Theory and Simulation of Water-Oil Contacts

NASA Astrophysics Data System (ADS)

Tan, Liang

. Eventually the dispersant COREXIT 9500 was used predominantly in responding to this accident. The formulation of COREXIT dispersants is somewhat complicated and the various constituents (and their interactions) deserve exhaustive study. Here we focus on sorbitan monooleate (SPAN80), one important component of COREXIT 9500, and we investigate its behavior in oil-water-surfactant systems. Extensive all-atom molecular dynamics calculations on the water-squalane interface for nine different loadings with SPAN80, at T = 300K, are analyzed for the surface tension equation of state, desorption free energy profiles as they depend on loading, and to evaluate escape times for absorbed SPAN80 into the bulk phases. These results suggest that loading only weakly affects accommodation of a SPAN80 molecule by this squalane-water interface. Specifically, the surface tension equation of state is simple from conditions of low loading (high tension) to high loading (lower tension) studied, and the desorption free energy profiles are weakly dependent on loading here. The perpendicular motion of the centroid of the SPAN80 head-group ring is well-described by a diffusional model near the minimum of the desorption free energy profile. Lateral diffusional motion is weakly dependent on loading. Escape times evaluated on the basis of a diffusional model and the desorption free energies are 0.07 s (into the squalane) and 300 h (into the water). The latter value is consistent with irreversible absorption observed by related experimental work.

Toxicities of Oils, Dispersants and Dispersed Oils to Aquatic Plants: Summary and Database Value to Resource Sustainability

EPA Science Inventory

Understanding the phytotoxicities of crude and dispersed oils is important for near-shore ecosystem management, particularly post-oil spills. One source of information is toxicity data summaries which are scattered and outdated for aquatic plants and petrochemicals. As a resu...

High water content oil-external micellar dispersions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, S.C.; Roszelle, W.O.; Svaldi, M.A.

1970-02-24

A high water content oil-external micellar dispersion (containing 55 percent to about 90 percent water) was developed for enhanced oil recovery. The micellar slug contained petroleum sulfonate (molecular weight averaged at about 350 to about 525), hydrocarbon, water and cosurfactant. The micellar slug was driven by a mobility buffer slug, which consisted of No. 530 Pusher, fusel oil and the residue Palestine water (420 ppm TDS) from the Palestine water reservoir in Palestine, Illinois. Fired Berea sandstone cores (porosity near 20 percent) were saturated with water (18,000 ppm sodium chloride), flooded with sweet black crude oil from Henry lease inmore » Illinois (7 cp at 72/sup 0/F), and waterflooded with water from Henry lease (18,000 ppm TDS). A maximum recovery of 11.5 percent of oil in place was recovered by 2 percent pore volume of a micellar dispersion containing petroleum sulfonate (MW 406), crude oil, 70 percent by volume distilled water, and p-hexanol.« less

Dispersion Of Crude Oil And Petroleum Products In Freshwater

EPA Science Inventory

The objective of this research was to investigate the relationship between dispersion effectiveness in freshwater and the surfactant composition for fresh and weathered crude oil. Although limited research on the chemical dispersion of crude oil and petroleum products in freshwat...

Oil recovery method using high water content oil-external micellar dispersions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, S.C.; Roszelle, W.O.; Svaldi, M.A.

1971-10-19

A high water content oil-external micellar dispersion (containing 55 percent to about 90 percent water) was developed for enhanced oil recovery. The micellar slug contained petroleum sulfonate (molecular weight averaged at about 350 to about 525), hydrocarbon, water and cosurfactant. The micellar slug was driven by a mobility buffer slug, which consisted of No. 530 Pusher, fusel oil and the residue Palestine water (420 ppm TDS) from the Palestine water reservoir in Palestine, Illinois. Fired Berea sandstone cores (porosity near 20 percent) were saturated with water (18,000 ppm sodium chloride), flooded with sweet black crude oil from Henry lease inmore » Illinois (7 cp at 72/sup 0/F), and waterflooded with water from Henry lease (18,000 ppm TDS). A maximum recovery of 11.5 percent of oil in place was recovered by 2 percent pore volume of a micellar dispersion containing petroleum sulfonate (MW 406), 70 percent by volume distilled water, and p-hexanol.« less

BIODEGRADABILITY OF DISPERSED CRUDE OIL AT TWO DIFFERENT TEMPERATURES

EPA Science Inventory

Laboratory experiments were initiated to study the biodegradability of oil after dispersants were applied. Two experiments were conducted, one at 20 ^oC and the other at 5 ^oC. In both experiments, only the dispersed oil fraction was investigated. Each exper...

BIODEGRADABILITY OF DISPERSED CRUDE OIL AT TWO DIFFERENT TEMPERATURES

EPA Science Inventory

Laboratory experiments were initiated to study the biodegradability of crude oil after dispersants were applied. Two experiments were conducted, one at 20^oC and the other at 5^oC. In both experiments, only the dispersed oil fraction was investigated compared ...

Chemical dispersants enhance the activity of oil- and gas condensate-degrading marine bacteria.

PubMed

Tremblay, Julien; Yergeau, Etienne; Fortin, Nathalie; Cobanli, Susan; Elias, Miria; King, Thomas L; Lee, Kenneth; Greer, Charles W

2017-12-01

Application of chemical dispersants to oil spills in the marine environment is a common practice to disperse oil into the water column and stimulate oil biodegradation by increasing its bioavailability to indigenous bacteria capable of naturally metabolizing hydrocarbons. In the context of a spill event, the biodegradation of crude oil and gas condensate off eastern Canada is an essential component of a response strategy. In laboratory experiments, we simulated conditions similar to an oil spill with and without the addition of chemical dispersant under both winter and summer conditions and evaluated the natural attenuation potential for hydrocarbons in near-surface sea water from the vicinity of crude oil and natural gas production facilities off eastern Canada. Chemical analyses were performed to determine hydrocarbon degradation rates, and metagenome binning combined with metatranscriptomics was used to reconstruct abundant bacterial genomes and estimate their oil degradation gene abundance and activity. Our results show important and rapid structural shifts in microbial populations in all three different oil production sites examined following exposure to oil, oil with dispersant and dispersant alone. We found that the addition of dispersant to crude oil enhanced oil degradation rates and favored the abundance and expression of oil-degrading genes from a Thalassolituus sp. (that is, metagenome bin) that harbors multiple alkane hydroxylase (alkB) gene copies. We propose that this member of the Oceanospirillales group would be an important oil degrader when oil spills are treated with dispersant.

The Logistics of Oil Spill Dispersant Application. Volume I. Logistics-Related Properties of Oil Spill Dispersants.

DTIC Science & Technology

1982-11-01

time of application. Such designs were probably influenced by the ready availabilit " 51 of fire-fighting hoses on ships and tugs; the water stream not...8217 I I1 ---- i . . .. . IIII . . . I I PREFACE The use of chemicals for the dispersal of oil spilled on water has been the subject of discussion (and of...20 Oil Type, Weathering and Emulsification.. 20 Slick Thickness .......................... 28 Water Temperature

Dispersant use as a response to oil spills: toxicological effects on fish cardiac performance.

PubMed

Milinkovitch, Thomas; Thomas-Guyon, Hélène; Lefrançois, Christel; Imbert, Nathalie

2013-04-01

Dispersant use is a controversial technique used to respond to oil spills in nearshore areas. In order to assess the toxicity of this technique, this study evaluated the cardiac toxicological effects on juvenile golden grey mullets Liza aurata exposed for 48 h to either dispersant alone, chemically dispersed oil, mechanically dispersed oil, the water-soluble fraction of oil or a control condition. Following exposure, the positive inotropic effects of adrenaline were assessed in order to evaluate a potential impairment on the cardiac performance. The results revealed an impairment of the positive inotropic effects of adrenaline for all the contaminants (single dispersant, dispersed and undispersed oil, water-soluble fraction of oil). This suggests that: (1) cardiac performance is a valuable parameter to study the physiopathological effects of dispersed oil; (2) dispersant application is likely to impair cardiac performance.

The oil-dispersion bath in anthroposophic medicine--an integrative review.

PubMed

Büssing, Arndt; Cysarz, Dirk; Edelhäuser, Friedrich; Bornhöft, Gudrun; Matthiessen, Peter F; Ostermann, Thomas

2008-12-04

Anthroposophic medicine offers a variety of treatments, among others the oil-dispersion bath, developed in the 1930s by Werner Junge. Based on the phenomenon that oil and water do not mix and on recommendations of Rudolf Steiner, Junge developed a vortex mechanism which churns water and essential oils into a fine mist. The oil-covered droplets empty into a tub, where the patient immerses for 15-30 minutes. We review the current literature on oil-dispersion baths. The following databases were searched: Medline, Pubmed, Embase, AMED and CAMbase. The search terms were 'oil-dispersion bath' and 'oil bath', and their translations in German and French. An Internet search was also performed using Google Scholar, adding the search terms 'study' and 'case report' to the search terms above. Finally, we asked several experts for gray literature not listed in the above-mentioned databases. We included only articles which met the criterion of a clinical study or case report, and excluded theoretical contributions. Among several articles found in books, journals and other publications, we identified 1 prospective clinical study, 3 experimental studies (enrolling healthy individuals), 5 case reports, and 3 field-reports. In almost all cases, the studies described beneficial effects - although the methodological quality of most studies was weak. Main indications were internal/metabolic diseases and psychiatric/neurological disorders. Beyond the obvious beneficial effects of warm bathes on the subjective well-being, it remains to be clarified what the unique contribution of the distinct essential oils dispersed in the water can be. There is a lack of clinical studies exploring the efficacy of oil-dispersion baths. Such studies are recommended for the future.

Simulated distribution and ecotoxicity-based assessment of chemically-dispersed oil in Tokyo Bay.

PubMed

Koyama, Jiro; Imakado, Chie; Uno, Seiichi; Kuroda, Takako; Hara, Shouichi; Majima, Takahiro; Shirota, Hideyuki; Añasco, Nathaniel C

2014-08-30

To assess risks of chemically-dispersed oil to marine organisms, oil concentrations in the water were simulated using a hypothetical spill accident in Tokyo Bay. Simulated oil concentrations were then compared with the short-term no-observed effect concentration (NOEC), 0.01 mg/L, obtained through toxicity tests using marine diatoms, amphipod and fish. Area of oil concentrations higher than the NOEC were compared with respect to use and non-use of dispersant. Results of the simulation show relatively faster dispersion near the mouth of the bay compared to its inner sections which is basically related to its stronger water currents. Interestingly, in the inner bay, a large area of chemically-dispersed oil has concentrations higher than the NOEC. It seems emulsifying oil by dispersant increases oil concentrations, which could lead to higher toxicity to aquatic organisms. When stronger winds occur, however, the difference in toxic areas between use and non-use of dispersant is quite small. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of crude oil exposure and dispersant application on meiofauna: an intertidal mesocosm experiment.

PubMed

Elarbaoui, Soumaya; Richard, Marion; Boufahja, Fehmi; Mahmoudi, Ezzeddine; Thomas-Guyon, Hélène

2015-05-01

Dispersant application is used as a response technique to minimize the environmental risk of an oil spill. In nearshore areas, dispersant application is a controversial countermeasure: environmental benefits are counteracted by the toxicity of dispersant use. The effects of the use of chemical dispersants on meiobenthic organisms and nematodes were investigated in a mesocosm experiment. A 20 day experiment was performed in four experimental sets of mesocosms. In three of them, sediments were contaminated, respectively by oil (500 mg kg(-1)), dispersed oil (oil + 5% dispersant), and dispersant alone, whereas in the last set sediments were kept undisturbed and used as a reference (Re). Our results showed that the meiobenthic response to oil contamination was rapid, for copepods and nematodes. One-way ANOVA showed a significant decrease of the abundance of copepods. In the case of nematodes, univariate and multivariate analyses indicated a clear decrease of the abundance of the species after only 20 days of pollutant exposure and thus reducing Shannon-Wiener diversity and Pielou's evenness. In contrast, Sphaerolaimus gracilis and Sabateria sp. became more frequent within disturbed assemblages and appeared to be resistant and/or opportunistic species in the presence of these kinds of toxicants. Moreover, responses of copepods and nematodes to the treatment seemed to be the same irrespective of whether only oil or oil + dispersant was performed. The main toxicities of dispersed oil come not from the "composition of a newly formed oil and oil spill dispersant mixture" but from the "quantities of increased dispersed oil droplets".

The Deep-Sea Microbial Community from the Amazonian Basin Associated with Oil Degradation.

PubMed

Campeão, Mariana E; Reis, Luciana; Leomil, Luciana; de Oliveira, Louisi; Otsuki, Koko; Gardinali, Piero; Pelz, Oliver; Valle, Rogerio; Thompson, Fabiano L; Thompson, Cristiane C

2017-01-01

One consequence of oil production is the possibility of unplanned accidental oil spills; therefore, it is important to evaluate the potential of indigenous microorganisms (both prokaryotes and eukaryotes) from different oceanic basins to degrade oil. The aim of this study was to characterize the microbial response during the biodegradation process of Brazilian crude oil, both with and without the addition of the dispersant Corexit 9500, using deep-sea water samples from the Amazon equatorial margin basins, Foz do Amazonas and Barreirinhas, in the dark and at low temperatures (4°C). We collected deep-sea samples in the field (about 2570 m below the sea surface), transported the samples back to the laboratory under controlled environmental conditions (5°C in the dark) and subsequently performed two laboratory biodegradation experiments that used metagenomics supported by classical microbiological methods and chemical analysis to elucidate both taxonomic and functional microbial diversity. We also analyzed several physical-chemical and biological parameters related to oil biodegradation. The concomitant depletion of dissolved oxygen levels, oil droplet density characteristic to oil biodegradation, and BTEX concentration with an increase in microbial counts revealed that oil can be degraded by the autochthonous deep-sea microbial communities. Indigenous bacteria (e.g., Alteromonadaceae, Colwelliaceae , and Alcanivoracaceae ), archaea (e.g., Halobacteriaceae, Desulfurococcaceae , and Methanobacteriaceae ), and eukaryotic microbes (e.g., Microsporidia, Ascomycota, and Basidiomycota) from the Amazonian margin deep-sea water were involved in biodegradation of Brazilian crude oil within less than 48-days in both treatments, with and without dispersant, possibly transforming oil into microbial biomass that may fuel the marine food web.

Concentrations of viable oil-degrading microorganisms are increased in feces from Calanus finmarchicus feeding in petroleum oil dispersions.

PubMed

Størdal, Ingvild Fladvad; Olsen, Anders Johny; Jenssen, Bjørn Munro; Netzer, Roman; Hansen, Bjørn Henrik; Altin, Dag; Brakstad, Odd Gunnar

2015-09-15

Zooplankton are suggested to be biotic contributors to the transport and weathering of oil in marine environments due to their ingestion of oil. In the present experiment, feeding activity and microbial communities in feces from Calanus finmarchicus feeding in oil dispersions were characterized. Feeding activity was significantly reduced in oil dispersions. The microbial communities in clean and oil-containing copepod feces were dominated by Rhodobacteraceae family bacteria (Lesingera, Phaeobacter, Rugeria, and Sulfitobacter), which were suggested to be indigenous to copepod feces. The results also indicated that these bacteria were metabolizing oil compounds, as a significant increase in the concentrations of viable oil degrading microorganisms was observed in oil-containing feces. This study shows that bacteria in feces from copepods feeding in dilute oil dispersions have capacity for degradation of oil. Zooplankton may therefore contribute to weathering of oil by excreting feces with microbial communities already adapted to degradation of oil. Copyright © 2015 Elsevier Ltd. All rights reserved.

Extracellular Enzyme Activity Profile in a Chemically Enhanced Water Accommodated Fraction of Surrogate Oil: Toward Understanding Microbial Activities After the Deepwater Horizon Oil Spill

PubMed Central

Kamalanathan, Manoj; Xu, Chen; Schwehr, Kathy; Bretherton, Laura; Beaver, Morgan; Doyle, Shawn M.; Genzer, Jennifer; Hillhouse, Jessica; Sylvan, Jason B.; Santschi, Peter; Quigg, Antonietta

2018-01-01

Extracellular enzymes and extracellular polymeric substances (EPS) play a key role in overall microbial activity, growth and survival in the ocean. EPS, being amphiphilic in nature, can act as biological surfactant in an oil spill situation. Extracellular enzymes help microbes to digest and utilize fractions of organic matter, including EPS, which can stimulate growth and enhance microbial activity. These natural processes might have been altered during the 2010 Deepwater Horizon oil spill due to the presence of hydrocarbon and dispersant. This study aims to investigate the role of bacterial extracellular enzymes during exposure to hydrocarbons and dispersant. Mesocosm studies were conducted using a water accommodated fraction of oil mixed with the chemical dispersant, Corexit (CEWAF) in seawater collected from two different locations in the Gulf of Mexico and corresponding controls (no additions). Activities of five extracellular enzymes typically found in the EPS secreted by the microbial community – α- and β-glucosidase, lipase, alkaline phosphatase, leucine amino-peptidase – were measured using fluorogenic substrates in three different layers of the mesocosm tanks (surface, water column and bottom). Enhanced EPS production and extracellular enzyme activities were observed in the CEWAF treatment compared to the Control. Higher bacterial and micro-aggregate counts were also observed in the CEWAF treatment compared to Controls. Bacterial genera in the order Alteromonadaceae were the most abundant bacterial 16S rRNA amplicons recovered. Genomes of Alteromonadaceae commonly have alkaline phosphatase and leucine aminopeptidase, therefore they may contribute significantly to the measured enzyme activities. Only Alteromonadaceae and Pseudomonadaceae among bacteria detected here have higher percentage of genes for lipase. Piscirickettsiaceae was abundant; genomes from this order commonly have genes for leucine aminopeptidase. Overall, this study provides insights

A review of oil, dispersed oil and sediment interactions in the aquatic environment: influence on the fate, transport and remediation of oil spills.

PubMed

Gong, Yanyan; Zhao, Xiao; Cai, Zhengqing; O'Reilly, S E; Hao, Xiaodi; Zhao, Dongye

2014-02-15

The 2010 Deepwater Horizon oil spill has spurred significant amounts of researches on fate, transport, and environmental impacts of oil and oil dispersants. This review critically summarizes what is understood to date about the interactions between oil, oil dispersants and sediments, their roles in developing oil spill countermeasures, and how these interactions may change in deepwater environments. Effects of controlling parameters, such as sediment particle size and concentration, organic matter content, oil properties, and salinity on oil-sediment interactions are described in detail. Special attention is placed to the application and effects of oil dispersants on the rate and extent of the interactions between oil and sediment or suspended particulate materials. Various analytical methods are discussed for characterization of oil-sediment interactions. Current knowledge gaps are identified and further research needs are proposed to facilitate sounder assessment of fate and impacts of oil spills in the marine environment. Copyright © 2013 Elsevier Ltd. All rights reserved.

Using dispersants after oil spills: impacts on the composition and activity of microbial communities.

PubMed

Kleindienst, Sara; Paul, John H; Joye, Samantha B

2015-06-01

Dispersants are globally and routinely applied as an emergency response to oil spills in marine ecosystems with the goal of chemically enhancing the dissolution of oil into water, which is assumed to stimulate microbially mediated oil biodegradation. However, little is known about how dispersants affect the composition of microbial communities or their biodegradation activities. The published findings are controversial, probably owing to variations in laboratory methods, the selected model organisms and the chemistry of different dispersant-oil mixtures. Here, we argue that an in-depth assessment of the impacts of dispersants on microorganisms is needed to evaluate the planning and use of dispersants during future responses to oil spills.

Logistics of Oil Spill Dispersant Application. Volume II. Application Techniques, Stockpiling, Dispersant Selection Strategies

DOT National Transportation Integrated Search

1982-11-01

The use of chemicals for oil spill dispersal, while not presently widespread in the U.S., would have implications for the U.S. Coast Guard's Marine Environmental Protection program. This report explores the logistics of oil disperant application by t...

Wave Tank Studies On Formation And Transport Of OMA From The Chemically Dispersed Oil

EPA Science Inventory

The interaction of chemical dispersants and suspended sediments with crude oil influences the fate and transport of oil spills in coastal waters. A wave tank study was conducted to investigate the effects of chemical dispersants and mineral fines on dispersion of oil, formation ...

The Deep-Sea Microbial Community from the Amazonian Basin Associated with Oil Degradation

PubMed Central

Campeão, Mariana E.; Reis, Luciana; Leomil, Luciana; de Oliveira, Louisi; Otsuki, Koko; Gardinali, Piero; Pelz, Oliver; Valle, Rogerio; Thompson, Fabiano L.; Thompson, Cristiane C.

2017-01-01

One consequence of oil production is the possibility of unplanned accidental oil spills; therefore, it is important to evaluate the potential of indigenous microorganisms (both prokaryotes and eukaryotes) from different oceanic basins to degrade oil. The aim of this study was to characterize the microbial response during the biodegradation process of Brazilian crude oil, both with and without the addition of the dispersant Corexit 9500, using deep-sea water samples from the Amazon equatorial margin basins, Foz do Amazonas and Barreirinhas, in the dark and at low temperatures (4°C). We collected deep-sea samples in the field (about 2570 m below the sea surface), transported the samples back to the laboratory under controlled environmental conditions (5°C in the dark) and subsequently performed two laboratory biodegradation experiments that used metagenomics supported by classical microbiological methods and chemical analysis to elucidate both taxonomic and functional microbial diversity. We also analyzed several physical–chemical and biological parameters related to oil biodegradation. The concomitant depletion of dissolved oxygen levels, oil droplet density characteristic to oil biodegradation, and BTEX concentration with an increase in microbial counts revealed that oil can be degraded by the autochthonous deep-sea microbial communities. Indigenous bacteria (e.g., Alteromonadaceae, Colwelliaceae, and Alcanivoracaceae), archaea (e.g., Halobacteriaceae, Desulfurococcaceae, and Methanobacteriaceae), and eukaryotic microbes (e.g., Microsporidia, Ascomycota, and Basidiomycota) from the Amazonian margin deep-sea water were involved in biodegradation of Brazilian crude oil within less than 48-days in both treatments, with and without dispersant, possibly transforming oil into microbial biomass that may fuel the marine food web. PMID:28659874

The oil-dispersion bath in anthroposophic medicine – an integrative review

PubMed Central

Büssing, Arndt; Cysarz, Dirk; Edelhäuser, Friedrich; Bornhöft, Gudrun; Matthiessen, Peter F; Ostermann, Thomas

2008-01-01

Background Anthroposophic medicine offers a variety of treatments, among others the oil-dispersion bath, developed in the 1930s by Werner Junge. Based on the phenomenon that oil and water do not mix and on recommendations of Rudolf Steiner, Junge developed a vortex mechanism which churns water and essential oils into a fine mist. The oil-covered droplets empty into a tub, where the patient immerses for 15–30 minutes. We review the current literature on oil-dispersion baths. Methods The following databases were searched: Medline, Pubmed, Embase, AMED and CAMbase. The search terms were 'oil-dispersion bath' and 'oil bath', and their translations in German and French. An Internet search was also performed using Google Scholar, adding the search terms 'study' and 'case report' to the search terms above. Finally, we asked several experts for gray literature not listed in the above-mentioned databases. We included only articles which met the criterion of a clinical study or case report, and excluded theoretical contributions. Results Among several articles found in books, journals and other publications, we identified 1 prospective clinical study, 3 experimental studies (enrolling healthy individuals), 5 case reports, and 3 field-reports. In almost all cases, the studies described beneficial effects – although the methodological quality of most studies was weak. Main indications were internal/metabolic diseases and psychiatric/neurological disorders. Conclusion Beyond the obvious beneficial effects of warm bathes on the subjective well-being, it remains to be clarified what the unique contribution of the distinct essential oils dispersed in the water can be. There is a lack of clinical studies exploring the efficacy of oil-dispersion baths. Such studies are recommended for the future. PMID:19055811

Ocean experiments and remotely sensed images of chemically dispersed oil spills

NASA Technical Reports Server (NTRS)

Croswell, W. F.; Fedors, J. C.; Hoge, F. E.; Swift, R. N.; Johnson, J. C.

1983-01-01

A series of experiments was performed at sea where the effectiveness of dispersants applied from a helicopter was tested on fresh and weathered crude oils released from a surface research vessel. In conjunction with these experiments, remote sensing measurements using an array of airborne optical and microwave sensors were performed in order to aid in the interpretation of the dispersant effectiveness and to obtain quantitative images of oil on the sea under controlled conditions. Surface oil thickness and volume are inferred from airborne measurements using a dual-channel microwave imaging radiometer, aerial color photography, and an airborne oceanographic lidar. The remotely sensed measurements are compared with point sampled data obtained using a research vessel. The mass balance computations of surface versus subsurface oil volume using remotely sensed and point sampled data are consistent with each other and with the volumes of oil released. Data collected by the several techniques concur in indicating that, for the oils used and under the sea conditions encountered, the dispersant and application method are primarily useful when applied to fresh oil.

Oil Spills and Dispersants Can Cause the Initiation of Potentially Harmful Dinoflagellate Blooms ("Red Tides").

PubMed

Almeda, Rodrigo; Cosgrove, Sarah; Buskey, Edward J

2018-05-15

After oil spills and dispersant applications the formation of red tides or harmful algal blooms (HABs) has been observed, which can cause additional negative impacts in areas affected by oil spills. However, the link between oil spills and HABs is still unknown. Here, we present experimental evidence that demonstrates a connection between oil spills and HABs. We determined the effects of oil, dispersant-treated oil, and dispersant alone on the structure of natural plankton assemblages in the Northern Gulf of Mexico. In coastal waters, large tintinnids and oligotrich ciliates, major grazers of phytoplankton, were negatively affected by the exposure to oil and dispersant, whereas bloom-forming dinoflagellates ( Prorocentrum texanum, P. triestinum, and Scrippsiella trochoidea) notably increased their concentration. The removal of key grazers due to oil and dispersant disrupts the predator-prey controls ("top-down controls") that normally function in plankton food webs. This disruption of grazing pressure opens a "loophole" that allows certain dinoflagellates with higher tolerance to oil and dispersants than their grazers to grow and form blooms when there are no growth limiting factors (e.g., nutrients). Therefore, oil spills and dispersants can act as disrupters of predator-prey controls in plankton food webs and as indirect inducers of potentially harmful dinoflagellate blooms.

Fate of dispersants associated with the deepwater horizon oil spill.

PubMed

Kujawinski, Elizabeth B; Kido Soule, Melissa C; Valentine, David L; Boysen, Angela K; Longnecker, Krista; Redmond, Molly C

2011-02-15

Response actions to the Deepwater Horizon oil spill included the injection of ∼771,000 gallons (2,900,000 L) of chemical dispersant into the flow of oil near the seafloor. Prior to this incident, no deepwater applications of dispersant had been conducted, and thus no data exist on the environmental fate of dispersants in deepwater. We used ultrahigh resolution mass spectrometry and liquid chromatography with tandem mass spectrometry (LC/MS/MS) to identify and quantify one key ingredient of the dispersant, the anionic surfactant DOSS (dioctyl sodium sulfosuccinate), in the Gulf of Mexico deepwater during active flow and again after flow had ceased. Here we show that DOSS was sequestered in deepwater hydrocarbon plumes at 1000-1200 m water depth and did not intermingle with surface dispersant applications. Further, its concentration distribution was consistent with conservative transport and dilution at depth and it persisted up to 300 km from the well, 64 days after deepwater dispersant applications ceased. We conclude that DOSS was selectively associated with the oil and gas phases in the deepwater plume, yet underwent negligible, or slow, rates of biodegradation in the affected waters. These results provide important constraints on accurate modeling of the deepwater plume and critical geochemical contexts for future toxicological studies.

A laboratory study of particulate and gaseous emissions from crude oil and crude oil-dispersant contaminated seawater due to breaking waves

NASA Astrophysics Data System (ADS)

Afshar-Mohajer, Nima; Li, Cheng; Rule, Ana M.; Katz, Joseph; Koehler, Kirsten

2018-04-01

Crude oil spill incidents occur frequently causing a verity of occupational, ecological and environmental problems. Dispersants are applied to enhance the dispersion rate of crude oil slicks into the water column. In this study, the aerosol size distribution from 10 nm to 20 μm, total particle-bound aromatic hydrocarbons (pPAH) and volatile organic compounds (VOCs) are measured in a 6 x 0.3 x 0.6 m tank as plunging breaking waves entrain oil slicks. The experiments are performed for seawater with slicks of crude oil, crude oil-dispersant mixture and dispersant only. The measurements investigate the effects of wave energy and slick properties on the temporal evolution of the emissions. The total number concentrations of particles originating from the oil-dispersant mixture are 1-2 orders of magnitude higher than those of crude oil across the entire nano-scale range, reaching 100x for 20 nm particles. Conversely, the differences in concentration are small in the micron range. The average concentrations of pPAH are variable but similar (150-270 ng/m3). The VOC concentrations for crude oil-dispersant mixtures are 2-3 times lower than those of crude oil, presumably due to the surfactant effect on mass diffusion. The drastic increase in ultrafine particle concentrations may raise concerns about effects of inhalation by cleanup workers and downstream communities though VOC emissions reduce. Findings through this study provide insight into how the spray of dispersant may change the ratio of airborne particulate matter and VOC emissions from seawater due to natural processes.

Biodegradation and photooxidation of crude oil under natural sunlight in the northern Gulf of Mexico

NASA Astrophysics Data System (ADS)

Bacosa, H. P.; Erdner, D.; Liu, Z.

2016-02-01

An enormous amount of oil was observed in the deep and surface waters of the northern Gulf of Mexico (nGoM) following the Deepwater Horizon (DWH) spill. While the oil degradation and bacterial communities in the deep-sea plume have been widely investigated, the effect of sunlight on oil and bacterial assemblages in surface waters have received less attention. In this study, we amended surface water collected near the DWH site with crude oil and/or Corexit dispersant and incubated under natural sunlight in the nGoM for 36 d in summer of 2013. The residual alkanes, polycyclic aromatic hydrocarbons (PAHs), and alkalyted PAHs were analyzed by GC-MS, and bacterial community was determined via pyrosequencing. The results show that n-alkane biodegradation rate constants (first order) were ca. ten-fold higher than the photooxidation rate constants. While biodegradation was characterized by a lag phase, photooxidation rate constants for the 2-3 ring and 4-5 ring PAHs, were 0.08-0.98 day-1 and 0.01-0.07 day-1, respectively. Compared to biodegradation, photooxidation increased the transformation of 4-5 ring PAHs by 70% and 3-4 ring alkylated PAHs by 36%. Sunlight significantly reduced bacterial diversity and a driver of shifts in bacterial community structure in oil and Corexit treatments. In amended treatments, sunlight increased the relative abundances of Alteromonas, Marinobacter, Labrenzia, Sandarakinotalea, Halomonas and Bartonella, while the dark treatments enriched Thalassobius, Winogradskyella, Alcanivorax, Formosa, Eubacterium, Erythrobacter, Natronocella, and Pseudomonas. This suggests that different bacteria are degrading the hydrocarbons in the dark and under light exposure. In a follow up study using DNA-Stable isotope probing (SIP), we identified the alkane and PAH degraders using 13C-labeled hexadecane and phenanthrene, respectively. The results of metagenomic and metatranscriptomic analyses in the light and dark incubations will be presented. For the first

Effects of rainfall on oil droplet size and the dispersion of spilled oil with application to Douglas Channel, British Columbia, Canada.

PubMed

Wu, Yongsheng; Hannah, Charles G; Thupaki, Pramod; Mo, Ruping; Law, Brent

2017-01-15

Raindrops falling on the sea surface produce turbulence. The present study examined the influence of rain-induced turbulence on oil droplet size and dispersion of oil spills in Douglas Channel in British Columbia, Canada using hourly atmospheric data in 2011-2013. We examined three types of oils: a light oil (Cold Lake Diluent - CLD), and two heavy oils (Cold Lake Blend - CLB and Access Western Blend - AWB). We found that the turbulent energy dissipation rate produced by rainfalls is comparable to what is produced by wind-induced wave breaking in our study area. With the use of chemical dispersants, our results indicate that a heavy rainfall (rain rate>20mmh -1 ) can produce the maximum droplet size of 300μm for light oil and 1000μm for heavy oils, and it can disperse the light oil with fraction of 22-45% and the heavy oils of 8-13%, respectively. Heavy rainfalls could be a factor for the fate of oil spills in Douglas Channel, especially for a spill of light oil and the use of chemical dispersants. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Use of water-external micellar dispersions in oil recovery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, S.C.

1970-04-14

A water-external micellar dispersion followed by a mobility buffer and a water drive were used for enhanced oil recovery. Field Berea sandstone cores (19.6 percent porosity, 387 md permeability) were saturated with brine (16,500 ppM sodium chloride), flooded with crude oil from the Henry lease in Illinois (viscosity of 5.9 cp at 72/sup 0/F, specific gravity of 0.833), and waterflooded with water from Henry lease (17,210 ppM TDS). The micellar dispersion followed by the mobility buffer produced 99.6 percent of the oil in the core. The micellar slug contained ammonium petroleum sulfonate (MW 450), Henry crude oil, isopropanol, nonyl phenol,more » sodium hydroxide, and water from the Palestine water reservoir in Palestine, Illinois (412 ppM TDS). No. 530 Pusher, ammonium thiocyanate, isopropanol, and Palestine water were in the mobility buffer.« less

Chemically dispersed oil is cytotoxic and genotoxic to sperm whale skin cells.

PubMed

Wise, Catherine F; Wise, James T F; Wise, Sandra S; Wise, John Pierce

2018-06-01

Two major oil crises in United States history, the 1989 Exxon-Valdez oil spill in Alaska and the 2010 Deepwater Horizon Oil Rig explosion in the Gulf of Mexico, drew attention to the need for toxicological experiments on oil and chemically dispersed oil. We are still learning the effects these spills had on wildlife. However, little data is known about the toxicity of these substances in marine mammals. The objective of this study is to determine the toxicity of Alaskan oil, as well as chemically dispersed oil. Oil experiments were performed using the water accommodated fraction of Alaskan oil (WAF) and the chemically enhanced water accommodated fraction of Alaskan oil (CEWAF). The Alaskan WAF is not cytotoxic to sperm whale skin cells though it did induce chromosome damage; S9-mediated metabolism did not affect the cytotoxicity of WAF but did increase the levels of chromosome damage. Alaskan CEWAF is more cytotoxic and genotoxic than the WAF; S9 mediated metabolism increased both cytotoxicity and genotoxicity of CEWAF. Analysis of the PAH content of Alaskan WAF and CEWAF revealed a forty-fold increase in the total levels of PAHs in CEWAF compared to WAF. These findings show that chemically dispersed oil leads to higher levels of PAH exposure which are more toxic and likely to lead to longer and more persistent health effects. Copyright © 2017 Elsevier Inc. All rights reserved.

Initial community and environment determine the response of bacterial communities to dispersant and oil contamination.

PubMed

Ortmann, Alice C; Lu, YueHan

2015-01-15

Bioremediation of seawater by natural bacterial communities is one potential response to coastal oil spills, but the success of the approach may vary, depending on geographical location, oil composition and the timing of spill. The short term response of coastal bacteria to dispersant, oil and dispersed oil was characterized using 16S rRNA gene tags in two mesocosm experiments conducted two months apart. Despite differences in the amount of oil-derived alkanes across the treatments and experiments, increases in the contributions of hydrocarbon degrading taxa and decreases in common estuarine bacteria were observed in response to dispersant and/or oil. Between the two experiments, the direction and rates of changes in particulate alkane concentrations differed, as did the magnitude of the bacterial response to oil and/or dispersant. Together, our data underscore large variability in bacterial responses to hydrocarbon pollutants, implying that bioremediation success varies with starting biological and environmental conditions. Copyright © 2014 Elsevier Ltd. All rights reserved.

EPA's New Oil and Dispersant Testing Program

EPA Science Inventory

The U.S. EPA has initiated a new component of its oil spills research program to develop baseline data on the ecotoxicity of selected petroleum products and toxicity and efficacy of dispersant agents. Two diluted bitumens (dilbits) from the Alberta Tar Sands are currently being t...

Study of oil-water partitioning of a chemical dispersant using an acute bioassay with marine crustaceans

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wells, P.G.; Abernethy, S.; Mackay, D.

1982-01-01

The toxicity of seawater dispersions of a chemical dispersant to two marine crustaceans was investigated in the presence and absence of various quantities of a non-toxic mineral oil. From the results and a physical-chemical partitioning analysis, a limiting value of the oil-water partition coefficient of the toxic compounds is deduced suggesting that essentially all of the toxic compounds in the dispersant will partition into solution in water following dispersant application to an oil spill. This conclusion simplifies interpretation and prediction of the toxic effects of a dispersed oil spill. The combined bioassay-partitioning procedure may have applications to the study ofmore » the toxicity of other complex mixtures such as industrial effluents.« less

Gulf of Mexico Air Quality: CALIPSO Support for Gulf of Mexico Air Quality Relating to the Deepwater Horizon Oil Spill

NASA Technical Reports Server (NTRS)

Nguyen, Myngoc T.; Lapointe, Stephen; Jennings, Brittney; Zoumplis, Angela

2011-01-01

On April 20, 2010, an oil platform belonging to BP exploded and leaked a huge volume of oil into the Gulf of Mexico. In an effort to control the spread of the oil, BP applied dispersants such as Corexit and conducted in-situ burnings of the oil. This catastrophe created a complex chain of events that affected not only the fragile water and land ecosystems, but the humans who breathe the air every day. Thousands of people were exposed to fumes associated with oil vapors from the spill, burning of the oil, and the toxic mixture of dispersants. While aiding in clean-up efforts, local fishermen were directly exposure to fumes when working on the Gulf. A notable amount of Gulf Coast residents were also exposed to the oil fumes as seasonal southeasterly winds blew vapors toward land. The Volatile Organic Compounds (VOC) found in oil vapors include: benzene, toluene, ethyl benzene, xylene, naphthalene, hydrogen sulfide and particulate matter (PM). Increases in water temperature and sunlight due to the summer season allow for these VOCs and PM to evaporate into the air more rapidly. Aside from the VOCs found in oil vapors, the dispersant being used to break up the oil is highly toxic and is thought to be even more toxic than the oil itself (EPA website, 2010). To protect human health, the environment, and to make informed policy decisions relevant to the spill, the EPA Region 6 has continuously monitored the affected areas carefully for levels of pollutants in the outdoor air that are associated with petroleum products and the burning of oil along the coast. In an effort to prevent, prepare for, and respond to future oil spills that occur in and around inland waters of the United States, the EPA has been working with local, state, and federal response partners. Air quality measurements were collected by the EPA at five active monitoring systems stationed along the coast.

Biotransformation of petroleum hydrocarbons and microbial communities in seawater with oil dispersions and copepod feces.

PubMed

Størdal, Ingvild Fladvad; Olsen, Anders Johny; Jenssen, Bjørn Munro; Netzer, Roman; Altin, Dag; Brakstad, Odd Gunnar

2015-12-30

To determine biotransformation of components in crude oil dispersions in the presence of feces from marine copepods, dispersed oil was incubated alone, with the addition of clean or oil-containing feces. We hypothesized that the feces would contribute with nutrients to bacteria, and higher concentrations of oil-degrading bacteria, respectively. Presence of clean feces resulted in higher degradation of aromatic oil compounds, but lower degradation of n-alkanes. Presence of oil-containing feces resulted in higher degradation of n-alkanes. The effect of clean feces on aromatic compounds are suggested to be due to higher concentrations of nutrients in the seawater where aromatic degradation takes place, while the lower degradation of n-alkanes are suggested to be due to a preference by bacteria for feces over these compounds. Large aggregates were observed in oil dispersions with clean feces, which may cause sedimentation of un-weathered lipophilic oil compounds towards the seafloor if formed during oil spills. Copyright © 2015 Elsevier Ltd. All rights reserved.

Dispersed oil decreases the ability of a model fish (Dicentrarchus labrax) to cope with hydrostatic pressure.

PubMed

Dussauze, Matthieu; Pichavant-Rafini, Karine; Belhomme, Marc; Buzzacott, Peter; Privat, Killian; Le Floch, Stéphane; Lemaire, Philippe; Theron, Michaël

2017-01-01

Data on the biological impact of oil dispersion in deep-sea environment are scarce. Hence, the aim of this study was to evaluate the potential interest of a pressure challenge as a new experimental approach for the assessment of consequences of chemically dispersed oil, followed by a high hydrostatic pressure challenge. This work was conducted on a model fish: juvenile Dicentrarchus labrax. Seabass were exposed for 48 h to dispersant alone (nominal concentration (NC) = 4 mg L -1 ), mechanically dispersed oil (NC = 80 mg L -1 ), two chemically dispersed types of oil (NC = 50 and 80 mg L -1 with a dispersant/oil ratio of 1/20), or kept in clean seawater. Fish were then exposed for 30 min at a simulated depth of 1350 m, corresponding to pressure of 136 absolute atmospheres (ATA). The probability of fish exhibiting normal activity after the pressure challenge significantly increased from 0.40 to 0.55 when they were exposed to the dispersant but decreased to 0.26 and 0.11 in the case of chemical dispersion of oil (at 50 and 80 mg L -1 , respectively). The chemical dispersion at 80 mg L -1 also induced an increase in probability of death after the pressure challenge (from 0.08 to 0.26). This study clearly demonstrates the ability of a pressure challenge test to give evidence of the effects of a contaminant on the capacity of fish to face hydrostatic pressure. It opens new perspectives on the analysis of the biological impact of chemical dispersion of oil at depth, especially on marine species performing vertical migrations.

Toxicity of crude oil chemically dispersed in a wave tank to embryos of Atlantic herring (Clupea harengus).

PubMed

Greer, Colleen D; Hodson, Peter V; Li, Zhengkai; King, Thomas; Lee, Kenneth

2012-06-01

Tests of crude oil toxicity to fish are often chronic, exposing embryos from fertilization to hatch to oil solutions prepared using standard mixing procedures. However, during oil spills, fish are not often exposed for long periods and the dynamic nature of the ocean is not easily replicated in the lab. Our objective was to determine if brief exposures of Atlantic herring (Clupea harengus) embryos to dispersed oil prepared by standard mixing procedures was as toxic as oil dispersed in a more realistic model system. Embryos were first exposed to chemically dispersed Alaska North Slope crude and Arabian light crude oil for 2.4 h to 14 d from fertilization to determine if exposure time affected toxicity. Toxicity increased with exposure time, but 2.4-h exposures at realistic concentrations of oil induced blue-sac disease and reduced the percentage of normal embryos at hatch; there was little difference in toxicity between the two oils. Secondly, oil was chemically dispersed in a wave tank to determine if the resultant oil solutions were as toxic to herring embryos as laboratory-derived dispersed oil using a single exposure period of 24 h. Samples taken 15 min postdispersion were more toxic than laboratory-prepared solutions, but samples taken at 5, 30, and 60 min postdispersion were less toxic. Overall, the laboratory- and wave tank-derived solutions of dispersed oil provided similar estimates of toxicity despite differences in the methods for preparing test solutions, suggesting that laboratory and wave tank data are a reliable basis for ecological risk assessments of spilled oil. Copyright © 2012 SETAC.

AN EXPERIMENTAL STUDY OF THE EFFECTS OF CHEMICALLY DISPERSED OIL ON FEATHER STRUCTURE AND WATERPROOFING IN COMMON MURRES ( URIA AALGE).

PubMed

Whitmer, Emily R; Elias, Becky A; Harvey, Danielle J; Ziccardi, Michael H

2018-04-01

Following an oil spill in the marine environment, chemical dispersants, which increase oil droplet formation and distribution into the water column, are assumed to provide a net benefit to seabirds by reducing the risk of exposure to oil on the water surface. However, few data are available regarding acute, external impacts of exposure to dispersed oil. We evaluated the effects of known concentrations of dispersant and crude oil in artificial seawater on live Common Murres ( Uria aalge). Waterproofing and microscopic feather geometry were evaluated over time and compared to pre-exposure values. Birds exposed to a high concentration of dispersant experienced an immediate, life-threatening loss of waterproofing and buoyancy, both of which resolved within 2 d. Birds exposed to oil, or a dispersant and oil mixture, experienced dose-dependent waterproofing impairment without resolution over 2 d. Alterations in feather geometry were observed in oil-exposed or dispersant- and oil-exposed birds and were associated with increased odds of waterproofing impairment compared to control birds. At a given contaminant concentration, there were no significant differences in waterproofing between oil-exposed and dispersant- and oil-exposed birds. We found that acute, external effects of oil and dispersed oil exposure are comparable and dose-dependent. Our results also indicate that a zero-risk assumption should not be used when seabirds are present within the dispersant application zone.

Unexpected Interaction with Dispersed Crude Oil Droplets Drives Severe Toxicity in Atlantic Haddock Embryos

PubMed Central

Sørhus, Elin; Edvardsen, Rolf B.; Karlsen, Ørjan; Nordtug, Trond; van der Meeren, Terje; Thorsen, Anders; Harman, Christopher; Jentoft, Sissel; Meier, Sonnich

2015-01-01

The toxicity resulting from exposure to oil droplets in marine fish embryos and larvae is still subject for debate. The most detailed studies have investigated the effects of water-dissolved components of crude oil in water accommodated fractions (WAFs) that lack bulk oil droplets. Although exposure to dissolved petroleum compounds alone is sufficient to cause the characteristic developmental toxicity of crude oil, few studies have addressed whether physical interaction with oil micro-droplets are a relevant exposure pathway for open water marine speices. Here we used controlled delivery of mechanically dispersed crude oil to expose pelagic embryos and larvae of a marine teleost, the Atlantic haddock (Melanogrammus aeglefinus). Haddock embryos were exposed continuously to two different concentrations of dispersed crude oil, high and low, or in pulses. By 24 hours of exposure, micro-droplets of oil were observed adhering and accumulating on the chorion, accompanied by highly elevated levels of cyp1a, a biomarker for exposure to aromatic hydrocarbons. Embryos from all treatment groups showed abnormalities representative of crude oil cardiotoxicity at hatch (5 days of exposure), such as pericardial and yolk sac edema. Compared to other species, the frequency and severity of toxic effects was higher than expected for the waterborne PAH concentrations (e.g., 100% of larvae had edema at the low treatment). These findings suggest an enhanced tissue uptake of PAHs and/or other petroleum compounds from attached oil droplets. These studies highlight a novel property of haddock embryos that leads to greater than expected impact from dispersed crude oil. Given the very limited number of marine species tested in similar exposures, the likelihood of other species with similar properties could be high. This unanticipated result therefore has implications for assessing the ecological impacts of oil spills and the use of methods for dispersing oil in the open sea. PMID:25923774

Dispersant Effectiveness Of Heavy Fuel Oils Using The Baffled Flask Test

EPA Science Inventory

Dispersants have been widely used as a primary response measure for marine oil spills around the world. Recently, the U.S. Environmental Protection Agency (EPA) developed an improved laboratory dispersant testing protocol, called the Baffled Flask Test (BFT). The BFT protocol w...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baca, B.J.; Getter, C.D.

Turtle grass beds, a valuable natural resource, are diminishing throughout the tropics because of damage from dredging, boats, and other factors. The toxicity of chemical dispersants and crude oil to turtle grass was determined in the laboratory to assess the potential for damage from spills occurring in the field. Studies of water-soluble fractions (WSF) of crude oil in static bioassays showed that a chemical dispersant (Corexit 9527) increased the amount of total oil in water more than 50-fold. The toxicity of chemically dispersed oil was assessed by conventional (96-h 50% lethal concentration) methods in static systems, and the results weremore » compared with toxicity measurements where the system was flushed after 12 h. Prudhoe Bay crude WSF was more toxic than dispersed oil or dispersant alone, possibly because of the large component of benzene, toluene, and C-2 benzene. The percentage of green (chlorophyllous) leaves was useful as evidence of toxicity. The importance of anatomical features such as recessed meristem and abundant leaf sheaths in protecting the growing region from waterborne pollutants was evident.« less

CHARACTERISTICS OF SPILLED OILS, FUELS, AND PETROLEUM PRODUCTS: 3A. SIMULATION OF OIL SPILLS AND DISPERSANTS UNDER CONDITIONS OF UNCERTAINTY

EPA Science Inventory

At the request of the US EPA Oil Program Center, ERD is developing an oil spill model that focuses on fate and transport of oil components under various response scenarios. This model includes various simulation options, including the use of chemical dispersing agents on oil sli...

Oil, oil dispersants and related substances in the marine environment

NASA Astrophysics Data System (ADS)

Gunkel, W.; Gassmann, G.

1980-03-01

Of all substances threatening life in the seas, oil has received by far the most attention from the public, administrators, politicians and scientists. The main reasons for this are: (1) even limited amounts of oil are easily visible; (2) oil can exert obvious negative effects, e. g. extensive damage to birds and other animals, impairment of the recreational value of beaches and marinas, losses in fisheries due to tainting of catches and rejection by the public of seafood from areas known to have been recently polluted. In addition, dramatic tanker accidents are widely publicized. During the last decade tens of thousands of papers have been published about the impact of oil on the marine environment, and we are well informed about most basic facts, such as input and fate of oil, toxicity to adult organisms and recolonization. Due to considerable sophistication of analytical techniques, especially the introduction of glass-capillary gas chromatography, we are well aware that recently formed biogenic hydrocarbons by far extend the input directly due to pollution. Large gaps exist in our knowledge about sedimentation and transport of weathered oil, natural degradation rates, and the flow of hydrocarbons through the food web. Relatively little is known about the influence of oil and dispersants upon complex ecosystems. The often mentioned suspicion of increased cancer probability in humans due to seafood contaminated by hydrocarbons has not been substantiated; in fact, it seems unlikely that such an effect exists. By far the greatest uncertainty about potential oil impact concerns possible negative effects of hydrocarbons on chemical communication mechanisms between organisms. Intensive studies of behaviour scientists working with concentrations far below the toxic level are needed in fisheries biology, zoology and botany. Most cases of oil contamination known thus far have been limited in space and time; the oil has turned out to be degradable by natural processes

Hsp60-induced tolerance in the rotifer Brachionus plicatilis exposed to multiple environmental contaminants.

PubMed

Wheelock, C E; Wolfe, M F; Olsen, H; Tjeerdema, R S; Sowby, M L

1999-04-01

Hsp60 induction was selected as a sublethal endpoint of toxicity for Brachionus plicatilis exposed to a water accommodated fraction (WAF) of Prudhoe Bay crude oil (PBCO), a PBCO/dispersant (Corexit 9527(R)) fraction and Corexit 9527(R) alone. To examine the effect of multiple stressors, exposures modeled San Francisco Bay, where copper levels are approximately 5 microgram/L, salinity is 22 per thousand, significant oil transport and refining occurs, and petroleum releases have occurred historically. Rotifers were exposed to copper at 5 microgram/L for 24 h, followed by one of the oil/dispersant preparations for 24 h. Batch-cultured rotifers were used in this study to model wild populations instead of cysts. SDS-PAGE with Western Blotting using hsp60-specific antibodies and chemiluminescent detection were used to isolate, identify, and measure induced hsp60 as a percentage of control values. Both PBCO/dispersant and dispersant alone preparations induced significant levels of hsp60. However, hsp60 expression was reduced to that of controls at high WAF concentrations, suggesting interference with protein synthesis. Rotifers that had been preexposed to copper maintained elevated levels of hsp60 upon treatment with WAF at all concentrations. Results suggest that induction of hsp60 by chronic low-level exposure may serve as a protective mechanism against subsequent or multiple stressors and that hsp60 levels are not additive for the toxicants tested in this study, giving no dose-response relationship. The methods employed in this study could be useful for quantifying hsp60 levels in wild rotifer populations.

Differentiating the roles of photooxidation and biodegradation in the weathering of Light Louisiana Sweet crude oil in surface water from the Deepwater Horizon site.

PubMed

Bacosa, Hernando P; Erdner, Deana L; Liu, Zhanfei

2015-06-15

We determined the contributions of photooxidation and biodegradation to the weathering of Light Louisiana Sweet crude oil by incubating surface water from the Deepwater Horizon site under natural sunlight and temperature conditions. N-alkane biodegradation rate constants were ca. ten-fold higher than the photooxidation rate constants. For the 2-3 ring and 4-5 ring polycyclic aromatic hydrocarbons (PAHs), photooxidation rate constants were 0.08-0.98day(-1) and 0.01-0.07day(-1), respectively. The dispersant Corexit enhanced degradation of n-alkanes but not of PAHs. Compared to biodegradation, photooxidation increased transformation of 4-5 ring PAHs by 70% and 3-4 ring alkylated PAHs by 36%. For the first time we observed that sunlight inhibited biodegradation of pristane and phytane, possibly due to inhibition of the bacteria that can degrade branched-alkanes. This study provides quantitative measures of oil degradation under relevant field conditions crucial for understanding and modeling the fate of spilled oil in the northern Gulf of Mexico. Copyright © 2015 Elsevier Ltd. All rights reserved.

The effect of dispersed Petrobaltic oil droplet size on photosynthetically active radiation in marine environment.

PubMed

Haule, Kamila; Freda, Włodzimierz

2016-04-01

Oil pollution in seawater, primarily visible on sea surface, becomes dispersed as an effect of wave mixing as well as chemical dispersant treatment, and forms spherical oil droplets. In this study, we examined the influence of oil droplet size of highly dispersed Petrobaltic crude on the underwater visible light flux and the inherent optical properties (IOPs) of seawater, including absorption, scattering, backscattering and attenuation coefficients. On the basis of measured data and Mie theory, we calculated the IOPs of dispersed Petrobaltic crude oil in constant concentration, but different log-normal size distributions. We also performed a radiative transfer analysis, in order to evaluate the influence on the downwelling irradiance Ed, remote sensing reflectance Rrs and diffuse reflectance R, using in situ data from the Baltic Sea. We found that during dispersion, there occurs a boundary size distribution characterized by a peak diameter d0  = 0.3 μm causing a maximum E d increase of 40% within 0.5-m depth, and the maximum Ed decrease of 100% at depths below 5 m. Moreover, we showed that the impact of size distribution on the "blue to green" ratios of Rrs and R varies from 24% increase to 27% decrease at the same crude oil concentration.

Toxicities of crude oils and oil-dispersant mixtures to juvenile rabbitfish, Siganus rivulatus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eisler, R.; Kissil, G.W.

1975-01-01

Toxicities were determined for two crude oils, one from the Persian Gulf (Iran) and one from the Sinai Peninsula (Gulf of Suez), to rabbitfish, Siganus rivulatus, an economically important species of teleost from the Red Sea. Also tested for toxicity were ST 5, a chemical oil dispersant, and oil-ST 5 mixtures in the ratio 10:1 vol/vol. Static tests conducted in small (3-liter) jars at 41 /sup 0///sub 00/ salinity and 23/sup 0/C produced LC/sub 50/ (168 h) values of 0.74 ml/liter for Iranian crude, 14.5 ml/liter for Sinai crude, and 0.010 ml/liter for ST 5; LC/sub 50/ values for oil-STmore » 5 mixtures reflected biocidal properties of ST 5 alone. Iranian oil became less toxic with increasing time in seawater over a period of 168 hours; the reverse was observed for Sinai crude. ST 5 exhibited a dramatic reduction in lethality after 2 hours in the assay medium. The most toxic component tested of Iranian crude was the lowest-boiling fraction; with Sinai crude it was the highest-boiling fraction; with ST 5 the volatile surfactant component accounted for almost all deaths. Liver enlargement in rabbitfish was linked with exposure to comparatively high concentrations of crude oil. High sublethal levels of ST 5 caused reductions in blood hematocrit. Rabbitfish survival at a given petrochemical concentration was highest at intermediate salinities of 30-50 /sup 0///sub 00/ in the salinity range tested of 20 to 60 /sup 0///sub 00/. Rabbitfish were more resistant to crudes and oil-dispersant mixtures in continuous flow bioassays conducted in large tanks than in static jar bioassays. Tank tests also suggested that mortalities were higher among toxicant-stressed fish confined 0.2 to 1.0 meters from the surface than among fish held 1.0 to 1.8 m from the surface. (auth)« less

Combined effects of Corexit EC 9500A with secondary abiotic and biotic factors in the rotifer Brachionus plicatilis.

PubMed

Williams, Michael B; Powell, Mickie L; Watts, Stephen A

2016-10-01

We examined lethality and behavioral effects of Corexit EC 9500A (C-9500A) exposure on the model marine zooplankton Brachionus plicatilis singularly and in combination with abiotic and biotic factors. C-9500A exposure at standard husbandry conditions (17.5ppt, 24°C, 200 rotifer*mL(-1) density) identified the 24h median lethal concentration, by Probit analysis, to be 107ppm for cultured B. plicatilis. Rotifers surviving exposure to higher concentrations (100 and 150ppm) exhibited a decreased swimming velocity and a reduced net to gross movement ratio. Significant interaction between C-9500A exposure and temperature or salinity was observed. Upper thermal range was reduced and maximal salinity stress was seen as ca. 25ppt. Increased or decreased nutritional availability over the exposure period did not significantly alter mortality of B. plicatilis populations at the concentrations tested. Results from this study may be useful for predicting possible outcomes on marine zooplankton following dispersant application under diverse natural conditions. Copyright © 2016 Elsevier Inc. All rights reserved.

Submersible optical sensors exposed to chemically dispersed crude oil: wave tank simulations for improved oil spill monitoring.

PubMed

Conmy, Robyn N; Coble, Paula G; Farr, James; Wood, A Michelle; Lee, Kenneth; Pegau, W Scott; Walsh, Ian D; Koch, Corey R; Abercrombie, Mary I; Miles, M Scott; Lewis, Marlon R; Ryan, Scott A; Robinson, Brian J; King, Thomas L; Kelble, Christopher R; Lacoste, Jordanna

2014-01-01

In situ fluorometers were deployed during the Deepwater Horizon (DWH) Gulf of Mexico oil spill to track the subsea oil plume. Uncertainties regarding instrument specifications and capabilities necessitated performance testing of sensors exposed to simulated, dispersed oil plumes. Dynamic ranges of the Chelsea Technologies Group AQUAtracka, Turner Designs Cyclops, Satlantic SUNA and WET Labs, Inc. ECO, exposed to fresh and artificially weathered crude oil, were determined. Sensors were standardized against known oil volumes and total petroleum hydrocarbons and benzene-toluene-ethylbenzene-xylene measurements-both collected during spills, providing oil estimates during wave tank dilution experiments. All sensors estimated oil concentrations down to 300 ppb oil, refuting previous reports. Sensor performance results assist interpretation of DWH oil spill data and formulating future protocols.

Comparative Toxicity of Eight Oil Dispersant Products on Two Gulf of Mexico Aquatic Test Species

EPA Science Inventory

This report is the first of a round of toxicity testing data for eight oil dispersants that have been authorized for use on the National Contingency Plan (NCP) Product Schedule, which is a list of authorized dispersants and other chemicals that may be used to respond to oil disch...

Assessing chronic fish health: An application to a case of an acute exposure to chemically treated crude oil.

PubMed

Mauduit, F; Domenici, P; Farrell, A P; Lacroix, C; Le Floch, S; Lemaire, P; Nicolas-Kopec, A; Whittington, M; Zambonino-Infante, J L; Claireaux, G

2016-09-01

Human alteration of marine ecosystems is substantial and growing. Yet, no adequate methodology exists that provides reliable predictions of how environmental degradation will affect these ecosystems at a relevant level of biological organization. The primary objective of this study was to develop a methodology to evaluate a fish's capacity to face a well-established environmental challenge, an exposure to chemically dispersed oil, and characterize the long-term consequences. Therefore, we applied high-throughput, non-lethal challenge tests to assess hypoxia tolerance, temperature susceptibility and maximal swimming speed as proxies for a fish's functional integrity. These whole animal challenge tests were implemented before (1 month) and after (1 month) juvenile European sea bass (Dicentrarchus labrax) had been acutely exposed (48h) to a mixture containing 0.08gL(-1) of weathered Arabian light crude oil plus 4% dispersant (Corexit© EC9500A), a realistic exposure concentration during an oil spill. In addition, experimental populations were then transferred into semi-natural tidal mesocosm ponds and correlates of Darwinian fitness (growth and survival) were monitored over a period of 4 months. Our results revealed that fish acutely exposed to chemically dispersed oil remained impaired in terms of their hypoxia tolerance and swimming performance, but not in temperature susceptibility for 1 month post-exposure. Nevertheless, these functional impairments had no subsequent ecological consequences under mildly selective environmental conditions since growth and survival were not impacted during the mesocosm pond study. Furthermore, the earlier effects on fish performance were presumably temporary because re-testing the fish 10 months post-exposure revealed no significant residual effects on hypoxia tolerance, temperature susceptibility and maximal swimming speed. We propose that the functional proxies and correlates of Darwinian fitness used here provide a useful

Impact of mixing time and energy on the dispersion effectiveness and droplets size of oil.

PubMed

Pan, Zhong; Zhao, Lin; Boufadel, Michel C; King, Thomas; Robinson, Brian; Conmy, Robyn; Lee, Kenneth

2017-01-01

The effects of mixing time and energy on Alaska Northern Slope (ANS) and diluted bitumen Cold Lake Blend (CLB) were investigated using EPA baffled flask test. Dispersion effectiveness and droplet size distribution were measured after 5-120 min. A modeling method to predict the mean droplet size was introduced for the first time to tentatively elucidate the droplet size breakup mechanism. The ANS dispersion effectiveness greatly increased with dispersant and mixing energy. However, little CLB dispersion was noted at small energy input (ε = 0.02 Watt/kg). With dispersant, the ANS droplet size distribution reached quasi-equilibrium within 10 min, but that of CLB seems to reach quasi-equilibrium after 120 min. Dispersants are assumed ineffective on high viscosity oils because dispersants do not penetrate them. We provide an alternative explanation based on the elongation time of the droplets and its residence in high intensity zones. When mixing energy is small, CLB did not disperse after 120 min, long enough to allow the surfactant penetration. Our findings suggest that dispersants may disperse high viscosity oils at a rougher sea state and a longer time. The latter could determine how far offshore one can intervene for effective responses to a high viscosity oil spill offshore. Copyright © 2016 Elsevier Ltd. All rights reserved.

Reynolds number scaling to predict droplet size distribution in dispersed and undispersed subsurface oil releases.

PubMed

Li, Pu; Weng, Linlu; Niu, Haibo; Robinson, Brian; King, Thomas; Conmy, Robyn; Lee, Kenneth; Liu, Lei

2016-12-15

This study was aimed at testing the applicability of modified Weber number scaling with Alaska North Slope (ANS) crude oil, and developing a Reynolds number scaling approach for oil droplet size prediction for high viscosity oils. Dispersant to oil ratio and empirical coefficients were also quantified. Finally, a two-step Rosin-Rammler scheme was introduced for the determination of droplet size distribution. This new approach appeared more advantageous in avoiding the inconsistency in interfacial tension measurements, and consequently delivered concise droplet size prediction. Calculated and observed data correlated well based on Reynolds number scaling. The relation indicated that chemical dispersant played an important role in reducing the droplet size of ANS under different seasonal conditions. The proposed Reynolds number scaling and two-step Rosin-Rammler approaches provide a concise, reliable way to predict droplet size distribution, supporting decision making in chemical dispersant application during an offshore oil spill. Copyright © 2016 Elsevier Ltd. All rights reserved.

Adhesion of mechanically and chemically dispersed crude oil droplets to eggs of Atlantic cod (Gadus morhua) and haddock (Melanogrammus aeglefinus).

PubMed

Hansen, Bjørn Henrik; Sørensen, Lisbet; Carvalho, Patricia Almeira; Meier, Sonnich; Booth, Andy M; Altin, Dag; Farkas, Julia; Nordtug, Trond

2018-05-30

Crude oil accidentally spilled into the marine environment undergoes natural weathering processes that result in oil components being dissolved into the water column or present in particulate form as dispersed oil droplets. Oil components dissolved in seawater are typically considered as more bioavailable to pelagic marine organisms and the main driver of crude oil toxicity, however, recent studies indicate that oil droplets may also contribute. The adhesion of crude oil droplets onto the eggs of pelagic fish species may cause enhanced transfer of oil components via the egg surface causing toxicity during the sensitive embryonic developmental stage. In the current study, we utilized an oil droplet dispersion generator to generate defined oil droplets sizes/concentrations and exposed Atlantic cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) to investigate if the potential for dispersed oil droplets to adhere onto the surface of eggs was species-dependent. The influence of a commercial chemical dispersant on the adhesion process was also studied. A key finding was that the adhesion of oil droplets was significantly higher for haddock than cod, highlighting key differences and exposure risks between the two species. Scanning electron microscopy indicates that the differences in oil droplet adhesion may be driven by the surface morphology of the eggs. Another important finding was that the adhesion capacity of oil droplets to fish eggs is significantly reduced (cod 37.3%, haddock 41.7%) in the presence of the chemical dispersant. Copyright © 2018 Elsevier B.V. All rights reserved.

Self-dispersed crumpled graphene balls in oil for friction and wear reduction

PubMed Central

Dou, Xuan; Koltonow, Andrew R.; He, Xingliang; Jang, Hee Dong; Wang, Qian; Chung, Yip-Wah; Huang, Jiaxing

2016-01-01

Ultrafine particles are often used as lubricant additives because they are capable of entering tribological contacts to reduce friction and protect surfaces from wear. They tend to be more stable than molecular additives under high thermal and mechanical stresses during rubbing. It is highly desirable for these particles to remain well dispersed in oil without relying on molecular ligands. Borrowing from the analogy that pieces of paper that are crumpled do not readily stick to each other (unlike flat sheets), we expect that ultrafine particles resembling miniaturized crumpled paper balls should self-disperse in oil and could act like nanoscale ball bearings to reduce friction and wear. Here we report the use of crumpled graphene balls as a high-performance additive that can significantly improve the lubrication properties of polyalphaolefin base oil. The tribological performance of crumpled graphene balls is only weakly dependent on their concentration in oil and readily exceeds that of other carbon additives such as graphite, reduced graphene oxide, and carbon black. Notably, polyalphaolefin base oil with only 0.01–0.1 wt % of crumpled graphene balls outperforms a fully formulated commercial lubricant in terms of friction and wear reduction. PMID:26811466

Relative Sensitivity of Arctic Species to Physically and Chemically Dispersed Oil Determined from Three Hydrocarbon Measures of Aquatic Toxicity

EPA Science Inventory

The risks to Arctic species from oil releases is a global concern, but their sensitivity to chemically dispersed oil has not been assessed using a curated and standardized dataset from spiked declining tests. Species sensitivity to dispersed oil was determined by their position w...

The influence of coastal fronts on the movement and dispersion of oil slicks. [Delaware Bay

NASA Technical Reports Server (NTRS)

Klemas, V. (Principal Investigator); Davis, G.; Kupferman, S.

1976-01-01

The author has identified the following significant results. LANDSAT, aircraft, and boats were used successfully to study estuarine and coastal fronts or boundaries. Horizontal salinity gradients of 4% in one meter and convergence velocities of the order of 0.1 m/sec were observed. Visibility improved from one meter to two meters as certain boundaries were crossed. Fronts near the mouth of the bay are associated with the tidal exchange with shelf water. By capturing and holding oil slicks, these frontal systems also significantly influence the movement and dispersion of oil slicks in Delaware Bay. Recent oil slick tracking experiments conducted to verify a predictive oil dispersion and movement model have shown that during certain parts of the tidal cycle the oil slicks tend to line up along boundaries.

Microbial inhibitory and radical scavenging activities of cold-pressed terpeneless Valencia orange (Citrus sinensis) oil in different dispersing agents.

PubMed

Chalova, Vesela I; Crandall, Philip G; Ricke, Steven C

2010-04-15

Due to their low solubility in water, oil-based bioactive compounds require dispersion in a surface-active agent or appropriate solvents to ensure maximum contact with microorganisms. These combinations, however, may change their physical and/or chemical characteristics and consequently alter the desired functionality. The objective of this study was to determine the impact of selected dispersing agents, ethanol, dimethyl sulfoxide (DMSO), and Tween-80, on cold-pressed terpeneless (CPT) Valencia orange oil to function as a free radical scavenger and an antimicrobial food additive. When dissolved in ethanol or DMSO, the orange oil fraction had similar minimum inhibitory concentrations (MIC) for Listeria monocytogenes ATCC 19 115 (0.3% and 0.25% v/v respectively), which were significantly lower (P oil dispersion systems exhibited an intermediate MIC (0.75% v/v) for Lactobacillus plantarum WCFS1. The orange oil (up to 3%) in an aqueous solution of 0.1% Tween-80 yielded no inhibitory activities against any of the test bacteria. However, the 1% natural orange oil dispersed in Tween-80 exhibited 56.86% 2,2-diphenyl-1-picryl hydrazyl (DPPH) radical inhibition versus 18.37% and 16.60% when the same level of orange oil was dissolved in DMSO or ethanol, respectively. At the same orange oil concentration, the oil/Tween-80 suspension yielded 57.92% neutralization of hydroxyl radicals. This represents 71.37% of the mannitol antioxidant activity, which was used as a positive control. These findings suggest that Tween-80 is an appropriate dispersing agent only if the antioxidant functionality is desired. If both antimicrobial and antioxidant properties are needed, the CPT Valencia orange oil should be dispersed in either DMSO or ethanol. (c) 2010 Society of Chemical Industry.

Analysis of Eight Oil Spill Dispersants Using Rapid, In Vitro Tests for Endocrine and Other Biological Activity

EPA Science Inventory

The Deepwater Horizon oil spill has led to the use of >1 M gallons of oil spill dispersants, which are mixtures of surfactants and solvents. Because of this large scale use there is a critical need to understand the potential for toxicity of the currently used dispersant and pote...

Size Distribution and Dispersion of Droplets Generated by Impingement of Breaking Waves on Oil Slicks

NASA Astrophysics Data System (ADS)

Li, C.; Miller, J.; Wang, J.; Koley, S. S.; Katz, J.

2017-10-01

This laboratory experimental study investigates the temporal evolution of the size distribution of subsurface oil droplets generated as breaking waves entrain oil slicks. The measurements are performed for varying wave energy, as well as large variations in oil viscosity and oil-water interfacial tension, the latter achieved by premixing the oil with dispersant. In situ measurements using digital inline holography at two magnifications are applied for measuring the droplet sizes and Particle Image Velocimetry (PIV) for determining the temporal evolution of turbulence after wave breaking. All early (2-10 s) size distributions have two distinct size ranges with different slopes. For low dispersant to oil ratios (DOR), the transition between them could be predicted based on a turbulent Weber (We) number in the 2-4 range, suggesting that turbulence plays an important role. For smaller droplets, all the number size distributions have power of about -2.1, and for larger droplets, the power decreases well below -3. The measured steepening of the size distribution over time is predicted by a simple model involving buoyant rise and turbulence dispersion. Conversely, for DOR 1:100 and 1:25 oils, the diameter of slope transition decreases from ˜1 mm to 46 and 14 µm, respectively, much faster than the We-based prediction, and the size distribution steepens with increasing DOR. Furthermore, the concentration of micron-sized droplets of DOR 1:25 oil increases for the first 10 min after entrainment. These phenomena are presumably caused by the observed formation and breakup oil microthreads associated with tip streaming.

A new perspective of particle adsorption: Dispersed oil and granular materials interactions in simulated coastal environment.

PubMed

Meng, Long; Bao, Mutai; Sun, Peiyan

2017-09-15

This study, adsorption behaviors of dispersed oil in seawaters by granular materials were explored in simulation environment. We quantitatively demonstrated the dispersed oil adsorbed by granular materials were both dissolved petroleum hydrocarbons (DPHs) and oil droplets. Furthermore, DPHs were accounted for 42.5%, 63.4%, and 85.2% (35.5% was emulsion adsorption) in the adsorption of dispersed oil by coastal rocks, sediments, and bacterial strain particles respectively. Effects of controlling parameters, such as temperature, particle size and concentration on adsorption of petroleum hydrocarbons were described in detail. Most strikingly, adsorption concentration was followed a decreasing order of bacterial strain (0.5-2μm)>sediments (0.005-0.625mm)>coastal rocks (0.2-1cm). With particle concentration or temperature increased, adsorption concentration increased for coastal rocks particle but decreased for sediments particle. Besides, particle adsorption rate of petroleum hydrocarbons (n-alkanes and PAHs) was different among granular materials during 60 days. Copyright © 2017 Elsevier Ltd. All rights reserved.

Interfacial film formation: influence on oil spreading rates in lab basin tests and dispersant effectiveness testing in a wave tank.

PubMed

King, Thomas L; Clyburne, Jason A C; Lee, Kenneth; Robinson, Brian J

2013-06-15

Test facilities such as lab basins and wave tanks are essential when evaluating the use of chemical dispersants to treat oil spills at sea. However, these test facilities have boundaries (walls) that provide an ideal environment for surface (interfacial) film formation on seawater. Surface films may form from surfactants naturally present in crude oil as well as dispersant drift/overspray when applied to an oil spill. The objective of this study was to examine the impact of surface film formation on oil spreading rates in a small scale lab basin and on dispersant effectiveness conducted in a large scale wave tank. The process of crude oil spreading on the surface of the basin seawater was influenced in the presence of a surface film as shown using a 1st order kinetic model. In addition, interfacial film formation can greatly influence chemically dispersed crude oil in a large scale dynamic wave tank. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Sensitivity of eastern oyster (Crassostrea virginica) spermatozoa and oocytes to dispersed oil: Cellular responses and impacts on fertilization and embryogenesis.

PubMed

Vignier, J; Volety, A K; Rolton, A; Le Goïc, N; Chu, F-L E; Robert, R; Soudant, P

2017-06-01

The 2010 Deepwater Horizon (DWH) oil spill released millions of barrels of oil and dispersant into the Gulf of Mexico. The timing of the spill coincided with the spawning season of Crassostrea virginica. Consequently, gametes released in the water were likely exposed to oil and dispersant. This study aimed to (i) evaluate the cellular effects of acute exposure of spermatozoa and oocytes to surface slick oil, dispersed mechanically (HEWAF) and chemically (CEWAF), using flow-cytometric (FCM) analyses, and (ii) determine whether the observed cellular effects relate to impairments of fertilization and embryogenesis of gametes exposed to the same concentrations of CEWAF and HEWAF. Following a 30-min exposure, the number of spermatozoa and their viability were reduced due to a physical action of oil droplets (HEWAF) and a toxic action of CEWAF respectively. Additionally, reactive oxygen species (ROS) production in exposed oocytes tended to increase with increasing oil concentrations suggesting that exposure to dispersed oil resulted in an oxidative stress. The decrease in fertilization success (1-h), larval survival (24-h) and increase in abnormalities (6-h and 24-h) may be partly related to altered cellular characteristics. FCM assays are a good predictor of sublethal effects especially on fertilization success. These data suggest that oil/dispersant are cytotoxic to gametes, which may affect negatively the reproduction success and early development of oysters. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ecological considerations for the use of dispersants in oil spill response

USGS Publications Warehouse

Lindstedt-Siva, J.; Albers, P.H.; Fucik, K.W.; Maynard, N.G.; Allen, Tom E.

1984-01-01

A multidisciplinary task force with membership from government agencies, academia, and industry is developing ecologically based guidelines for dispersant use in marine and estuarine environments. The guidelines are organized by habitat type (e.g., coral reefs, rocky shores, bird habitats) and consider dispersant use to protect the habitats from impact, to mitigate impacts, and to clean the habitats after a spill. Each guideline contains a description of the habitat type covered, recommendations for dispersant use, and a background section reviewing the relevant literature. The goal is to minimize the ecological impacts of oil spills. Aesthetic, socioeconomic, and political factors are not considered, although it is recognized that these are important concerns during spill response. Use of dispersants is considered along with other appropriate countermeasures and compared with the “no cleanup” alternative.

OIL SPILL DISPERSANT EFFECTIVENESS PROTOCOL. II: PERFORMANCE OF THE REVISED PROTOCOL

EPA Science Inventory

The current U.S. Environmental Protection Agency (EPA) protocol for testing the effectiveness of dispersants for use in treating oil spills on the open water, the swirling flask test (SFT), has been found to give widely varying results in the hands of different testing laborator...

Mutagenicity of diesel exhaust particles and oil shale particles dispersed in lecithin surfactant.

PubMed

Wallace, W E; Keane, M J; Hill, C A; Xu, J; Ong, T M

1987-01-01

Diesel exhaust particulate material from exhaust pipe scrapings of two trucks, diluted automobile diesel exhaust particulate material collected on filters, and two oil shale ores were prepared for the Ames mutagenicity assay by dichloromethane (DCM) extraction, by dispersion into 0.85% saline, or by dispersion into dipalmitoyl lecithin (DPL) emulsion in saline. Salmonella typhimurium TA98 was used to detect frameshift mutagens in the samples. Samples of diesel soot gave positive mutagenic responses with both DCM extraction and DPL dispersion, with the DPL dispersion giving higher results in some cases. The results suggest that possible mutagens associated with inhaled particles may be dispersed or solubilized into the phospholipid component of pulmonary surfactant and become active in such a phase.

Lab tests on the biodegradation of chemically dispersed oil should consider the rapid dilution that occurs at sea.

PubMed

Lee, Kenneth; Nedwed, Tim; Prince, Roger C; Palandro, David

2013-08-15

Most crude oils spread on open water to an average thickness as low as 0.1 mm. The application of dispersants enhances the transport of oil as small droplets into the water column, and when combined with the turbulence of 1 m waves will quickly entrain oil into the top 1 m of the water column, where it rapidly dilutes to concentrations less than 100 ppm. In less than 24 h, the dispersed oil is expected to mix into the top 10 m of the water column and be diluted to concentrations well below 10 ppm, with dilution continuing as time proceeds. Over the multiple weeks that biodegradation takes place, dispersed oil concentrations are expected to be below 1 ppm. Measurements from spills and wave basin studies support these calculations. Published laboratory studies focused on the quantification of contaminant biodegradation rates have used concentrations orders of magnitude greater than this, as it was necessary to ensure the concentrations of hydrocarbons and other chemicals were higher than the detection limits of chemical analysis. However, current analytical methods can quantify individual alkanes and PAHs (and their alkyl homologues) at ppb and ppm levels. To simulate marine biodegradation of dispersed oil at dilute concentrations commonly encountered in the field, laboratory studies should be conducted at similarly low hydrocarbon concentrations. Copyright © 2013 Elsevier Ltd. All rights reserved.

Toxicity of Chevron Escravos crude oil and chemical dispersant on guinea pig testicular function.

PubMed

Afonne, Onyenmechi Johnson; Onyiaorah, Igwebuike Victor; Orisakwe, Orish Ebere

2013-01-01

Chemical contaminants have been found to affect reproductive functions in mammals. This study investigated the effect of Chevron Escravos crude oil and Emulsol L.W. dispersant on the testicular functions of guinea pig. Eight groups of seven sexually mature male guinea pigs each were given 1250, 2500, or 5000 mg/kg of crude oil and dispersant for 7 days. The fluid and food intake and body weight of the animals were measured daily throughout the study. After the exposure period, sperm quality analysis was carried out, and fructose and lactate dehydrogenase were analyzed in tissue homogenate, while testosterone and estradiol were assayed in blood. The right testis was also processed for histological analysis. The epididymal sperm number and fructose level of treated animals showed a significant dose-dependent decrease (p<0.05) compared with controls. Also, sperm motility and morphology were altered in the treated groups, while testosterone and estradiol levels were increased significantly (p<0.05) in the treated groups. Histological examination showed signs of toxicity in the treated animals. From the findings, it was evident that Chevron Escravos crude oil and Emulsol L.W. oil dispersant are able to cause acute testicular toxicity in guinea pigs. The possible mechanism of toxicity is suggested to be by stimulation of hormone production from the adrenal cortex, causing a negative feedback on gonadotropin-releasing hormone in the pituitary gland to suppress spermatogenesis.

Electrical properties of dispersions of graphene in mineral oil

DOE Office of Scientific and Technical Information (OSTI.GOV)

Monteiro, O. R., E-mail: othon.monteiro@bakerhughes.com

2014-02-03

Dispersions of graphene in mineral oil have been prepared and electrical conductivity and permittivity have been measured. The direct current (DC) conductivity of the dispersions depends on the surface characteristics of the graphene platelets and followed a percolation model with a percolation threshold ranging from 0.05 to 0.1 wt. %. The difference in DC conductivities can be attributed to different states of aggregation of the graphene platelets and to the inter-particle electron transfer, which is affected by the surface radicals. The frequency-dependent conductivity (σ(ω)) and permittivity (ε(ω)) were also measured. The conductivity of dispersions with particle contents much greater than themore » percolation threshold remains constant and equal to the DC conductivity at low frequencies ω with and followed a power-law σ(ω)∝ ω{sup s} dependence at very high frequencies with s≈0.9. For dispersions with graphene concentration near the percolation threshold, a third regime was displayed at intermediate frequencies indicative of interfacial polarization consistent with Maxwell-Wagner effect typically observed in mixtures of two (or more) phases with very distinct electrical and dielectric properties.« less

Mesocosm study on weathering characteristics of Iranian Heavy crude oil with and without dispersants.

PubMed

Joo, Changkyu; Shim, Won Joon; Kim, Gi Beum; Ha, Sung Yong; Kim, Moonkoo; An, Joon Geon; Kim, Eunsic; Kim, Beom; Jung, Seung Won; Kim, Young-Ok; Yim, Un Hyuk

2013-03-15

The environmental fate of Iranian Heavy crude oil (IHC) with and without an added oil spill dispersant (OSD) has been studied using a 1000 kL capacity in situ mesocosm. Physical weathering and chemical composition changes of the oil were monitored for 77 days. Compound-specific effects of the OSD could be observed as changes over time in the content of the total petroleum hydrocarbon (TPH), unresolved complex mixture (UCM), alkanes, polycyclic aromatic hydrocarbons (PAHs), hopanes and steranes in the oil. As oil weathers, most hydrocarbons showed a rapid decreasing phase followed by a slowdown and stabilization. Recalcitrant biomarkers, however, showed a different trend. An increase in hydrocarbon contents in the form of UCM occurred after OSD treatment. The enhanced solubility of the low molecular weight PAHs by the OSD decreased the half-life of the alkylated PAHs in the OD. After 77 days of exposure at the sea surface, both the oils with and without the OSD exhibited moderate weathering. Most of the source diagnostic indices maintained their source information, and the weathering indices indicated that evaporation, dissolution, and dispersion were the major weathering processes. The mass balance of the weathered oil was calculated using laboratory and mesocosm data and the results demonstrate the importance of using a mesocosm for the production of environmentally realistic data. Copyright © 2013 Elsevier B.V. All rights reserved.

CHARACTERISTICS OF SPILLED OILS, FUELS, AND PETROLEUM PRODUCTS: 2A. DISPERSANT EFFECTIVENESS DATA FOR A SUITE OF ENVIRONMENTAL CONDITIONS - THE EFFECTS OF TEMPERATURE, VOLATILIZATION, AND ENERGY

EPA Science Inventory

Chemical dispersants are used in oil spill response operations to enhance the dispersion of oil slicks at sea as small oil droplets in the water column. To assess the impacts of dispersant usage on oil spills, US EPA is developing a simulation model called the EPA Research Object...

Development of a unified oil droplet size distribution model with application to surface breaking waves and subsea blowout releases considering dispersant effects.

PubMed

Li, Zhengkai; Spaulding, Malcolm; French McCay, Deborah; Crowley, Deborah; Payne, James R

2017-01-15

An oil droplet size model was developed for a variety of turbulent conditions based on non-dimensional analysis of disruptive and restorative forces, which is applicable to oil droplet formation under both surface breaking-wave and subsurface-blowout conditions, with or without dispersant application. This new model was calibrated and successfully validated with droplet size data obtained from controlled laboratory studies of dispersant-treated and non-treated oil in subsea dispersant tank tests and field surveys, including the Deep Spill experimental release and the Deepwater Horizon blowout oil spill. This model is an advancement over prior models, as it explicitly addresses the effects of the dispersed phase viscosity, resulting from dispersant application and constrains the maximum stable droplet size based on Rayleigh-Taylor instability that is invoked for a release from a large aperture. Copyright © 2016 Elsevier Ltd. All rights reserved.

Genotoxic potential and heart rate disorders in the Mediterranean mussel Mytilus galloprovincialis exposed to Superdispersant-25 and dispersed diesel oil.

PubMed

Martinović, Rajko; Kolarević, Stoimir; Kračun-Kolarević, Margareta; Kostić, Jovana; Marković, Sandra; Gačić, Zoran; Kljajić, Zoran; Vuković-Gačić, Branka

2015-07-01

The effects of ex situ exposure of Mytilus galloprovincialis to Superdispersant-25 (S-25), diesel oil and dispersed diesel oil mixtures were studied by the impact on level of DNA damage in haemocytes (comet assay) and the cardiac activity patterns of mussels. Specimens were exposed for 72 h in a static system to diesel oil (100 μL/L and 1 mL/L), S-25 (5 and 50 μL/L), and dispersed diesel oil mixtures M1 (diesel oil 100 μL/L + S-25 5 μL/L) and M2 (diesel oil 1 mL/L + S-25 50 μL/L). For positive control 40 μM CdCl2 was used. The comet assay results indicated genotoxic potential of S-25 while the effects of diesel oil alone were not observed. The highest response was detected for M1 while the effects of M2 were not detected. The heart rate disorders were recorded for the diesel oil (1 mL/L), S-25 (50 μL/L) and both dispersed diesel oil mixtures. Copyright © 2015 Elsevier Ltd. All rights reserved.

Investigation of Dispersion, Stability, and Tribological Performance of Oil-Based Aluminum Oxide Nanofluids

DTIC Science & Technology

2012-01-01

protection of the 4140 steel using the alumina nanoparticles. This means that the alumina particles primarily acted as third body abrasives in this...INVESTIGATION OF DISPERSION, STABILITY, AND TRIBOLOGICAL PERFORMANCE OF OIL-BASED ALUMINUM OXIDE NANOFLUIDS THESIS FOR THE... TRIBOLOGICAL PERFORMANCE OF OIL-BASED ALUMINUM OXIDE NANOFLUIDS 5a. CONTRACT NUMBER W56H2V-08-C-0236 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6

Comparative effects of biological and chemical dispersants on the bioavailability and toxicity of crude oil to early life stages of marine medaka (Oryzias melastigma).

PubMed

Mu, Jingli; Jin, Fei; Ma, Xindong; Lin, Zhongsheng; Wang, Juying

2014-11-01

The authors assessed the bioavailability and chronic toxicity of water-accommodated fractions of crude oil (WAFs) and 2 dispersants plus dispersed crude oil (chemical dispersant + crude oil [CE-WAF] and biological dispersant + crude oil [BE-WAF]) on the early life stages of marine medaka, Oryzias melastigma. The results showed that the addition of the 2 dispersants caused a 3- and 4-fold increase in concentrations of summed priority polycyclic aromatic hydrocarbons (PAHs) and high-molecular-weight PAHs with 3 or more benzene rings. The chemical and biological dispersants increased the bioavailability (as measured by ethoxyresorufin-O-dethylase activity) of crude oil 6-fold and 3-fold, respectively. Based on nominal concentrations, chronic toxicity (as measured by deformity) in WAFs exhibited a 10-fold increase in CE-WAF and a 3-fold increase in BE-WAF, respectively. When total petroleum hydrocarbon was measured, the differences between WAF and CE-WAF treatments disappeared, and CE-WAF was approximately 10 times more toxic than BE-WAF. Compared with the chemical dispersant, the biological dispersant possibly modified the toxicity of oil hydrocarbons because of the increase in the proportion of 2- and 3-ringed PAHs in water. The chemical and biological dispersants enhanced short-term bioaccumulation and toxicity, through different mechanisms. These properties should be considered in addition to their efficacy in degrading oil when oil spill management strategies are selected. © 2014 SETAC.

In Vitro Assessment of Eight Oil Dispersants for Estrogenic, Androgenic, Anti-androgenic and Cytotoxicity in Cell-Based Assays.

EPA Science Inventory

Large amounts of dispersants have been used on the oil from the Deepwater Horizon spill and concern has arisen about the toxicity of the dispersants. Some of the dispersants reportedly contain nonylphenol ethoxylates which can degrade to estrogenic compounds, thus the potential...

Effects of ingested crude and dispersed crude oil on thermoregulation in ducks (Anas platyrhynchos)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jenssen, B.M.

1989-02-01

Thermoregulatory effects of ingested doses of Statfjord A crude oil and of this oil mixed with the dispersant Finasol OSR-5 were studied in adult domestic ducks (Anas platyrhynchos) exposed to ambient temperatures of +16 degrees C and -17 degrees C. The data show that ingestion of both the crude and the oil-dispersant mixture resulted in an increased body temperature during exposure to the low ambient temperature (-17 degrees C). Neither contaminant had any effect on body temperature during exposure to +16 degrees C. Ingestion of the contaminants had no effect on metabolic heat production at either ambient temperature. The breastmore » skin temperature of the ducks in both contaminated groups was significantly decreased when the ducks were exposed to the low ambient temperature. This indicates that the increase in body temperature observed in the contaminated ducks at the low ambient temperature is due to an increase in peripheral vasoconstriction.« less

The use of chemical dispersants to combat oil spills at sea: A review of practice and research needs in Europe.

PubMed

Chapman, Helen; Purnell, Karen; Law, Robin J; Kirby, Mark F

2007-07-01

In order to better understand the practice of dispersant use, a review has been undertaken of marine oil spills over a 10 year period (1995-2005), looking in particular at variations between different regions and oil-types. This viewpoint presents and analyses the review data and examines a range of dispersant use policies. The paper also discusses the need for a reasoned approach to dispersant use and introduces past cases and studies to highlight lessons learned over the past ten years, focussing on dispersant effectiveness and monitoring; toxicity and environmental effects; the use of dispersants in low salinity waters; response planning and future research needs.

Response of the bacterial community in oil-contaminated marine water to the addition of chemical and biological dispersants.

PubMed

Couto, Camila Rattes de Almeida; Jurelevicius, Diogo de Azevedo; Alvarez, Vanessa Marques; van Elsas, Jan Dirk; Seldin, Lucy

2016-12-15

The use of dispersants in different stages of the oil production chain and for the remediation of water and soil is a well established practice. However, the choice for a chemical or biological dispersant is still a controversial subject. Chemical surfactants that persist long in the environment may pose problems of toxicity themselves; therefore, biosurfactants are considered to constitute an environmentally friendly and effective alternative. Nevertheless, the putative effects of such agents on the microbiomes of oil-contaminated and uncontaminated marine environments have not been sufficiently evaluated. Here, we studied the effects of the surfactant Ultrasperse II ® and the surfactin (biosurfactant) produced by Bacillus sp. H2O-1 on the bacterial communities of marine water. Specifically, we used quantitative PCR and genetic fingerprint analyses to study the abundance and structure of the bacterial communities in marine water collected from two regions with contrasting climatic conditions. The addition of either chemical surfactant or biosurfactant influenced the structure and abundance of total and oil-degrading bacterial communities of oil-contaminated and uncontaminated marine waters. Remarkably, the bacterial communities responded similarly to the addition of oil and/or either the surfactant or the biosurfactant in both set of microcosms. After 30 days of incubation, the addition of surfactin enhanced the oil-degrading bacteria more than the chemical surfactant. However, no increase of hydrocarbon biodegradation values was observed, irrespective of the dispersant used. These data contribute to an increased understanding of the impact of novel dispersants on marine bacteriomes before commercial release into the environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Using bio-dispersive solution of chitosan for green dispersive liquid-liquid microextraction of trace amounts of Cu(II) in edible oils prior to analysis by ICP-OES.

PubMed

Limchoowong, Nunticha; Sricharoen, Phitchan; Techawongstien, Suchila; Chanthai, Saksit

2017-09-01

A green approach using chitosan solution as a novel bio-dispersive agent for the dispersive liquid-liquid microextraction (DLLME) of trace amounts of Cu(II) in edible oils is presented. An emulsion was formed by mixing the oil sample with 300µL of 0.25% (w/v) chitosan solution containing 200µL of 6molL -1 HCl. Deionized water was used to induce emulsion breaking without centrifugation. The centrifuged Cu(II) extract was collected and analyzed using an inductively coupled plasma-optical emission spectrometer. The detection and quantitation limits were 2.1 and 6.8µgL -1 , respectively. Trace amounts of Cu(II) in six edible oil samples were tested under optimum conditions for DLLME, with a recovery ranging from 90.3% to 109.3%. Therefore, the new dispersive agent in DLLME offers superior performance owing to the non-toxic nature of the solvent, short extraction time, high sensitivity, and easy operation. Copyright © 2017 Elsevier Ltd. All rights reserved.

UPTAKE AND EFFECTS OF DISPERSED OIL DROPLETS AND EMULSIFIED OIL BY ESTUARINE CRUSTACEANS IN THE GULF OF MEXICO

EPA Science Inventory

The results from this project will provide information on the extent of uptake of dispersed petroleum from the seawater and uptake of emulsified oil from the sediment by blue crabs and grass shrimp of different life history stages. The primary focus of the study will be eff...

Estimating sub-surface dispersed oil concentration using acoustic backscatter response.

PubMed

Fuller, Christopher B; Bonner, James S; Islam, Mohammad S; Page, Cheryl; Ojo, Temitope; Kirkey, William

2013-05-15

The recent Deepwater Horizon disaster resulted in a dispersed oil plume at an approximate depth of 1000 m. Several methods were used to characterize this plume with respect to concentration and spatial extent including surface supported sampling and autonomous underwater vehicles with in situ instrument payloads. Additionally, echo sounders were used to track the plume location, demonstrating the potential for remote detection using acoustic backscatter (ABS). This study evaluated use of an Acoustic Doppler Current Profiler (ADCP) to quantitatively detect oil-droplet suspensions from the ABS response in a controlled laboratory setting. Results from this study showed log-linear ABS responses to oil-droplet volume concentration. However, the inability to reproduce ABS response factors suggests the difficultly in developing meaningful calibration factors for quantitative field analysis. Evaluation of theoretical ABS intensity derived from the particle size distribution provided insight regarding method sensitivity in the presence of interfering ambient particles. Copyright © 2013 Elsevier Ltd. All rights reserved.

Fuel oil and dispersant toxicity to the Antarctic sea urchin (Sterechinus neumayeri).

PubMed

Alexander, Frances J; King, Catherine K; Reichelt-Brushett, Amanda J; Harrison, Peter L

2017-06-01

The risk of a major marine fuel spill in Antarctic waters is increasing, yet there are currently no standard or suitable response methods under extreme Antarctic conditions. Fuel dispersants may present a possible solution; however, little data exist on the toxicity of dispersants or fuels to Antarctic species, thereby preventing informed management decisions. Larval development toxicity tests using 3 life history stages of the Antarctic sea urchin (Sterechinus neumayeri) were completed to assess the toxicity of physically dispersed, chemically dispersed, and dispersant-only water-accommodated fractions (WAFs) of an intermediate fuel oil (IFO 180, BP) and the chemical dispersant Slickgone NS (Dasic International). Despite much lower total petroleum hydrocarbon concentrations, physically dispersed fuels contained higher proportions of low-to-intermediate weight carbon compounds and were generally at least an order of magnitude more toxic than chemically dispersed fuels. Based on concentrations that caused 50% abnormality (EC50) values, the embryonic unhatched blastula life stage was the least affected by fuels and dispersants, whereas the larval 4-armed pluteus stage was the most sensitive. The present study is the first to investigate the possible implications of the use of fuel dispersants for fuel spill response in Antarctica. The results indicate that the use of a fuel dispersant did not increase the hydrocarbon toxicity of IFO 180 to the early life stages of Antarctic sea urchins, relative to physical dispersal. Environ Toxicol Chem 2017;36:1563-1571. © 2016 SETAC. © 2016 SETAC.

Simulating oil droplet dispersal from the Deepwater Horizon spill with a Lagrangian approach

USGS Publications Warehouse

North, Elizabeth W.; Schlag, Zachary; Adams, E. Eric; Sherwood, Christopher R.; He, Ruoying; Hyun, Hoon; Socolofsky, Scott A.

2011-01-01

An analytical multiphase plume model, combined with time-varying flow and hydrographic fields generated by the 3-D South Atlantic Bight and Gulf of Mexico model (SABGOM) hydrodynamic model, were used as input to a Lagrangian transport model (LTRANS), to simulate transport of oil droplets dispersed at depth from the recent Deepwater Horizon MC 252 oil spill. The plume model predicts a stratification-dominated near field, in which small oil droplets detrain from the central plume containing faster rising large oil droplets and gas bubbles and become trapped by density stratification. Simulated intrusion (trap) heights of ∼ 310–370 m agree well with the midrange of conductivity-temperature-depth observations, though the simulated variation in trap height was lower than observed, presumably in part due to unresolved variability in source composition (percentage oil versus gas) and location (multiple leaks during first half of spill). Simulated droplet trajectories by the SABGOM-LTRANS modeling system showed that droplets with diameters between 10 and 50 μm formed a distinct subsurface plume, which was transported horizontally and remained in the subsurface for >1 month. In contrast, droplets with diameters ≥90 μm rose rapidly to the surface. Simulated trajectories of droplets ≤50 μm in diameter were found to be consistent with field observations of a southwest-tending subsurface plume in late June 2010 reported by Camilli et al. [2010]. Model results suggest that the subsurface plume looped around to the east, with potential subsurface oil transport to the northeast and southeast. Ongoing work is focusing on adding degradation processes to the model to constrain droplet dispersal.

Turbulent dispersion of slightly buoyant oil droplets and turbulent breakup of crude oil droplets mixed with dispersants

NASA Astrophysics Data System (ADS)

Gopalan, Balaji

In part I, high speed in-line digital holographic cinematography is used for studying turbulent diffusion of slightly buoyant 0.5-1.2 mm diameter diesel droplets (specific gravity of 0.85) and 50 mum diameter neutral density particles. Experiments are performed in a 50x50x70 mm3 sample volume in a controlled, nearly isotropic turbulence facility, which is characterized by 2-D PIV. An automated tracking program has been used for measuring velocity time history of more than 17000 droplets and 15000 particles. The PDF's of droplet velocity fluctuations are close to Gaussian for all turbulent intensities ( u'i ). The mean rise velocity of droplets is enhanced or suppressed, compared to quiescent rise velocity (Uq), depending on Stokes number at lower turbulence levels, but becomes unconditionally enhanced at higher turbulence levels. The horizontal droplet velocity rms exceeds the fluid velocity rms for most of the data, while the vertical ones are higher than the fluid only at the highest turbulence level. The scaled droplet horizontal diffusion coefficient is higher than the vertical one, for 1 < u'i /Uq < 5, consistent with trends of the droplet velocity fluctuations. Conversely, the scaled droplet horizontal diffusion timescale is smaller than the vertical one due to crossing trajectories effect. The droplet diffusion coefficients scaled by the product of turbulence intensity and an integral length scale is a monotonically increasing function of u'i /Uq. Part II of this work explains the formation of micron sized droplets in turbulent flows from crude oil droplets pre-mixed with dispersants. Experimental visualization shows that this breakup starts with the formation of very long and quite stable, single or multiple micro threads that trail behind millimeter sized droplets. These threads form in regions with localized increase in concentration of surfactant, which in turn depends on the flow around the droplet. The resulting reduction of local surface tension

Microbial communities related to biodegradation of dispersed Macondo oil at low seawater temperature with Norwegian coastal seawater

PubMed Central

Brakstad, Odd G; Throne-Holst, Mimmi; Netzer, Roman; Stoeckel, Donald M; Atlas, Ronald M

2015-01-01

The Deepwater Horizon (DWH) accident in 2010 created a deepwater plume of small oil droplets from a deepwater well in the Mississippi Canyon lease block 252 (‘Macondo oil’). A novel laboratory system was used in the current study to investigate biodegradation of Macondo oil dispersions (10 μm or 30 μm median droplet sizes) at low oil concentrations (2 mg l−1) in coastal Norwegian seawater at a temperature of 4–5°C. Whole metagenome analyses showed that oil biodegradation was associated with the successive increased abundances of Gammaproteobacteria, while Alphaproteobacteria (Pelagibacter) became dominant at the end of the experiment. Colwellia and Oceanospirillales were related to n-alkane biodegradation, while particularly Cycloclasticus and Marinobacter were associated with degradation of aromatic hydrocarbons (HCs). The larger oil droplet dispersions resulted in delayed sequential changes of Oceanospirillales and Cycloclasticus, related with slower degradation of alkanes and aromatic HCs. The bacterial successions associated with oil biodegradation showed both similarities and differences when compared with the results from DWH field samples and laboratory studies performed with deepwater from the Gulf of Mexico. PMID:26485443

Effect of Dispersants on the Biodegradation of South Louisiana Crude Oil at 5 and 25oC

EPA Science Inventory

This article reports biodegradation rates for a commercial dispersant, JD-2000, South Louisiana crude oil (SLC) alone, and SLC dispersed with JD-2000 at 5 and 25^oC. Results from the biodegradation experiments revealed that Component X, a chemical marker for JD-2000, r...

Relative sensitivity of Arctic species to physically and chemically dispersed oil determined from three hydrocarbon measures of aquatic toxicity.

PubMed

Bejarano, Adriana C; Gardiner, William W; Barron, Mace G; Word, Jack Q

2017-09-15

The risks to Arctic species from oil releases is a global concern, but their sensitivity to chemically dispersed oil has not been assessed using a curated and standardized dataset from spiked declining tests. Species sensitivity to dispersed oil was determined by their position within species sensitivity distributions (SSDs) using three measures of hydrocarbon toxicity: total petroleum hydrocarbons (TPH), polycyclic aromatic hydrocarbon (PAHs), and naphthalenes. Comparisons of SSDs with Arctic/sub-Arctic versus non-Arctic species, and across SSDs of compositionally similar oils, showed that Arctic and non-Arctic species have comparable sensitivities even with the variability introduced by combining data across studies and oils. Regardless of hydrocarbon measure, hazard concentrations across SSDs were protective of sensitive Arctic species. While the sensitivities of Arctic species to oil exposures resemble those of commonly tested species, PAH-based toxicity data are needed for a greater species diversity including sensitive Arctic species. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dynamics of solid dispersions in oil during the lubrication of point contacts. Part 1: Graphite

NASA Technical Reports Server (NTRS)

Cusano, C.; Sliney, H. E.

1981-01-01

A Hertzian contact was lubricated with dispersed graphite in mineral oils under boundary lubrication conditions. The contact was optically observed under pure rolling, combined rolling and sliding, and pure sliding conditions. The contact was formed with a steel ball on the flat surface of a glass disk. Photomicrographs are presented which show the distribution of the graphite in and around the contact. Friction and surface damage are also shown for conditions when the base oils are used alone and when graphite is added to the base oils. Under pure rolling and combined rolling and sliding conditions, it is found that, for low speeds, a graphite film can form which will separate the contacting surfaces. Under pure sliding conditions, graphite accumulates at the inlet and sweeps around the contact, but very little of the graphite passes through the contact. The accumulated graphite appears to act as a barrier which reduces the supply of oil available to the contact for boundary lubrication. Friction data show no clear short term beneficial or detrimental effect caused by addition of graphite to the base oil. However, during pure sliding, more abrasion occurs on the polished balls lubricated with the dispersion than on those lubricated with the base oil alone. All observations were for the special case of a highly-polished ball on a glass surface and may not be applicable to other geometries and materials, or to rougher surfaces.

Macondo-1 well oil in sediment and tarballs from the northern Gulf of Mexico shoreline

USGS Publications Warehouse

Wong, Florence L.; Rosenbauer, Robert J.; Campbell, Pamela L.; Lam, Angela; Lorenson, T.D.; Hostettler, Frances D.; Thomas, Burt

2011-01-01

From April 20 through July 15, 2010, an estimated 4.4 million barrels (1 barrel = 42 gallons [~700,000 cu m]) of crude oil spilled into the northern Gulf of Mexico (nGOM) from the ruptured British Petroleum (BP) Macondo-1 (M-1) well after the explosion of the drilling platform Deepwater Horizon. In addition, ~1.84 million gallons (~7,000 cu m) of hydrocarbon-based Corexit dispersants were applied to the oil both on and below the sea surface (Operational Science Advisory Team, 2010). An estimate of the total extent of the surface oil slick, derived from wind, ocean currents, aerial photography, and satellite imagery, was 68,000 square miles (~180,000 sq km; Amos and Norse, 2010). Spilled oil from this event impacted sensitive habitat along the shores of the nGOM. In response to this environmental catastrophe, the U.S. Geological Survey (USGS) collected coastal sediment and tarball samples along the shores of the nGOM from Texas to Florida before and after oil made landfall. These sites included priority areas of the nGOM at highest risk for oil contamination. These areas included coastal wetlands, shorelines, and barrier islands that could suffer severe environmental damage if a significant amount of oil came ashore. Samples were collected before oil reached land from 69 sites; 49 were revisited to collect samples after oil landfall. This poster focuses on the samples from locations that were sampled on both occasions. The USGS samples and one M-1 well-oil sample provided by BP were analyzed for a suite of diagnostic geochemical biomarkers. Aided by multivariate statistical analysis, the M-1 well oil was not detected in the samples collected before landfall but have been identified in sediment and tarballs collected from Louisiana, Alabama, Mississippi, and Florida after landfall. None of the sediment hydrocarbon extracts from Texas correlated with the M-1 well oil. Oil-impacted sediment is confined to the shoreline adjacent to the cumulative oil slick of the

Non-Dispersive Infrared Sensor for Online Condition Monitoring of Gearbox Oil.

PubMed

Rauscher, Markus S; Tremmel, Anton J; Schardt, Michael; Koch, Alexander W

2017-02-18

The condition of lubricating oil used in automotive and industrial gearboxes must be controlled in order to guarantee optimum performance and prevent damage to machinery parts. In normal practice, this is done by regular oil change intervals and routine laboratory analysis, both of which involve considerable operating costs. In this paper, we present a compact and robust optical sensor that can be installed in the lubrication circuit to provide quasi-continuous information about the condition of the oil. The measuring principle is based on non-dispersive infrared spectroscopy. The implemented sensor setup consists of an optical measurement cell, two thin-film infrared emitters, and two four-channel pyroelectric detectors equipped with optical bandpass filters. We present a method based on multivariate partial least squares regression to select appropriate optical bandpass filters for monitoring the oxidation, water content, and acid number of the oil. We perform a ray tracing analysis to analyze and correct the influence of the light path in the optical setup on the optical parameters of the bandpass filters. The measurement values acquired with the sensor for three different gearbox oil types show high correlation with laboratory reference data for the oxidation, water content, and acid number. The presented sensor can thus be a useful supplementary tool for the online condition monitoring of lubricants when integrated into a gearbox oil circuit.

Non-Dispersive Infrared Sensor for Online Condition Monitoring of Gearbox Oil

PubMed Central

Rauscher, Markus S.; Tremmel, Anton J.; Schardt, Michael; Koch, Alexander W.

2017-01-01

The condition of lubricating oil used in automotive and industrial gearboxes must be controlled in order to guarantee optimum performance and prevent damage to machinery parts. In normal practice, this is done by regular oil change intervals and routine laboratory analysis, both of which involve considerable operating costs. In this paper, we present a compact and robust optical sensor that can be installed in the lubrication circuit to provide quasi-continuous information about the condition of the oil. The measuring principle is based on non-dispersive infrared spectroscopy. The implemented sensor setup consists of an optical measurement cell, two thin-film infrared emitters, and two four-channel pyroelectric detectors equipped with optical bandpass filters. We present a method based on multivariate partial least squares regression to select appropriate optical bandpass filters for monitoring the oxidation, water content, and acid number of the oil. We perform a ray tracing analysis to analyze and correct the influence of the light path in the optical setup on the optical parameters of the bandpass filters. The measurement values acquired with the sensor for three different gearbox oil types show high correlation with laboratory reference data for the oxidation, water content, and acid number. The presented sensor can thus be a useful supplementary tool for the online condition monitoring of lubricants when integrated into a gearbox oil circuit. PMID:28218701

40 CFR 110.4 - Dispersants.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 22 2011-07-01 2011-07-01 false Dispersants. 110.4 Section 110.4 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS DISCHARGE OF OIL § 110.4 Dispersants. Addition of dispersants or emulsifiers to oil to be discharged that would circumvent the...

40 CFR 110.4 - Dispersants.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 23 2012-07-01 2012-07-01 false Dispersants. 110.4 Section 110.4 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS DISCHARGE OF OIL § 110.4 Dispersants. Addition of dispersants or emulsifiers to oil to be discharged that would circumvent the...

40 CFR 110.4 - Dispersants.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 21 2010-07-01 2010-07-01 false Dispersants. 110.4 Section 110.4 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS DISCHARGE OF OIL § 110.4 Dispersants. Addition of dispersants or emulsifiers to oil to be discharged that would circumvent the...

40 CFR 110.4 - Dispersants.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 22 2014-07-01 2013-07-01 true Dispersants. 110.4 Section 110.4 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS DISCHARGE OF OIL § 110.4 Dispersants. Addition of dispersants or emulsifiers to oil to be discharged that would circumvent the...

40 CFR 110.4 - Dispersants.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 23 2013-07-01 2013-07-01 false Dispersants. 110.4 Section 110.4 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS DISCHARGE OF OIL § 110.4 Dispersants. Addition of dispersants or emulsifiers to oil to be discharged that would circumvent the...

Dispersive liquid-liquid microextraction of phenolic compounds from vegetable oils using a magnetic ionic liquid.

PubMed

Zhu, Shuqiang; Wang, Lijun; Su, Along; Zhang, Haixia

2017-08-01

A novel method was developed for the determination of two endocrine-disrupting chemicals, bisphenol A and 4-nonylphenol, in vegetable oil by dispersive liquid-liquid microextraction followed by ultra high performance liquid chromatography with tandem mass spectrometry. Using a magnetic liquid as the microextraction solvent, several key parameters were optimized, including the type and volume of the magnetic liquid, extraction time, amount of dispersant, and the type of reverse extractant. The detection limits for bisphenol A and 4-nonylphenol were 0.1 and 0.06 μg/kg, respectively. The recoveries were 70.4-112.3%, and the relative standard deviations were less than 4.2%. The method is simple for the extraction of bisphenol A and 4-nonylphenol from vegetable oil and suitable for routine analysis. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect of a Dispersant Agent in Fine Coal Recovery from Washery Tailings by Oil Agglomeration (Preliminary Study)

NASA Astrophysics Data System (ADS)

Yasar, Özüm; Uslu, Tuncay

2017-12-01

Among the fine coal cleaning methods, the oil agglomeration process has important advantages such as high process recovery, more clean product, simple dewatering stage. Several coal agglomeration studies have been undertaken recently and effects of different variables on the process performance have been investigated. However, unlike flotation studies, most of the previous agglomeration studies have not used dispersing agents to minimize slime coating effects of clays. In this study, agglomeration process was applied for recovery of fine coals from coal washery tailings containing remarkable amount of fine coal. Negative effect of fine clays during recovery was tried to be eliminated by using dispersing agent instead of de-sliming. Although ash reductions over 90 % were achieved, performance remained below expectations in terms of combustible matter recovery. However, this study is a preliminary one. It is considered that more satisfied results will be obtained in the next studies by changing the variables such as solid ratio, oil dosage, dispersant type and dosage.

Asphaltene dispersants as demulsification aids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Manek, M.B.

1995-11-01

Destabilization of petroleum asphaltenes may cause a multitude of problems in crude oil recovery and production. One major problem is their agglomeration at the water-oil interface of crude oil emulsions. Once agglomeration occurs, destabilized asphaltenes can form a thick pad in the dehydration equipment, which significantly reduces the demulsification rate. Certain polymeric dispersants increase asphaltene solubilization in hydrocarbon media, and when used in conjunction with emulsion breakers, facilitate the demulsification process. Two case studies are presented that demonstrate how asphaltene dispersants can efficiently inhibit pad formation and help reduce demulsifier dosage. Criteria for dispersant application and selection are discussed, whichmore » include the application of a novel laboratory technique to assess asphaltene stabilization in the crude oil. The technique monitors asphaltene agglomeration while undergoing titration with an incompatible solvent (precipitant). The method was used to evaluate stabilization of asphaltenes in the crude oil and to screen asphaltene dispersants.« less

Science-based decision-making on the use of dispersants in the Deepwater Horizon oil spill

EPA Science Inventory

Prior to the DWH incident, most (if not all) existing oil spill response knowledgewas based on surface spills and surface applications of dispersant. The behavior ofdispersants subsea was (and still is) less understood, and previous research had notfocused on the duration or quan...

Contaminant levels in Gulf of Mexico reef fish after the Deepwater Horizon oil spill as measured by a fishermen-led testing program.

PubMed

Fitzgerald, Timothy P; Gohlke, Julia M

2014-01-01

The BP oil disaster posed a significant threat to the U.S. seafood industry. Invertebrates (shrimp, oyster, crab) and other nearshore species comprised the majority of postspill testing by federal and state agencies. Deeper water finfish were sampled less frequently, despite population ranges that overlapped with affected waters. We report on a voluntary testing program with Gulf of Mexico commercial fishermen to ensure the safety of their catch. Seven species of reef fish were tested for polycyclic aromatic hydrocarbons, several metals, and a constituent of Corexit 9500A and 9527A dispersants. Only two of 92 samples had detectable levels of benzo(a)pyrene-equivalents (a combined measure of carcinogenic potency across 7 different PAHs), which were still below federal safety thresholds. PAH ratios for these samples suggest pyrogenic (not petrogenic) contamination - indicating potential sources other than Deepwater Horizon. Metals were largely absent (cadmium, lead) or consistent with levels previously reported (mercury, arsenic). One notable exception was tilefish, which showed mercury concentrations lower than expected. We did not detect dispersant in any of our samples, indicating that it was not present in these species during the study period. Our findings suggest minimal risk to public health from these seafoods as a result of the disaster; however, the most contaminated areas were not sampled through this program.

Effect of Dispersion Method on Stability and Dielectric Strength of Transformer Oil-Based TiO2 Nanofluids.

PubMed

Lv, Yu-Zhen; Li, Chao; Sun, Qian; Huang, Meng; Li, Cheng-Rong; Qi, Bo

2016-12-01

Dispersion stability of nanoparticles in the liquid media is of great importance to the utilization in practice. This study aims to investigate the effects of mechanical dispersion method on the dispersibility of functionalized TiO 2 nanoparticles in the transformer oil. Dispersion methods, including stirring, ultrasonic bath, and probe processes, were systematically tested to verify their versatility for preparing stable nanofluid. The test results reveal that the combination of ultrasonic bath process and stirring method has the best dispersion efficiency and the obtained nanofluid possesses the highest AC breakdown strength. Specifically, after aging for 168 h, the size of nanoparticles in the nanofluid prepared by the combination method has no obvious change, while those obtained by the other three paths are increased obviously.

Comparative Toxicity of Louisiana Sweet Crude Oil (LSC) and Chemically Dispersed LSC to Two Gulf of Mexico Aquatic Test Species.

EPA Science Inventory

Environmental Protection Agency released peer reviewed results from the second phase of its independent toxicity testing on mixtures of eight oil dispersants with Louisiana Sweet Crude Oil. EPA conducted the tests as part of an effort to ensure that EPA decisions remain grounded ...

An insight into spore dispersal of Ganoderma boninense on oil palm.

PubMed

Sanderson, F R

2005-01-01

The disease of oil palm caused by Ganoderma boninense, although universally referred to as Ganoderma basal stem rot, occurs in three very distinct phases, with basal stem rot only part of the disease cycle. G. boninense also causes a seedling disease and an upper stem rot. An understanding of spore dispersal provides an insight into where spores of G. boninense have a role in the infection process. This role will be discussed in relation to each of these three infection phases. This understanding is a critical component of developing a successful disease control strategy.

DETERMINING DISPERSANT EFFECTIVENESS DATA FOR A SUITE OF ENVIRONMENTAL CONDITIONS

EPA Science Inventory

Chemical dispersants are used in oil spill response operations to enhance the dispersion of oil slicks at sea as small oil droplets in the water column. To assess the impacts of dispersant usage on oil spills, US EPA is developing a simulation model called the EPA Research Objec...

Conserving archaeological sites as biological and historical resources in the Gulf of Mexico: the effects of crude oil and dispersant on the biodiversity and corrosion potential of shipwreck bacterial biofilms

NASA Astrophysics Data System (ADS)

Salerno, J. L.; Little, B.; Lee, J.; Ray, R.; Hamdan, L. J.

2016-02-01

There are more than 2,000 documented shipwrecks in the Gulf of Mexico. Historic shipwrecks are invaluable cultural resources, but also serve as artificial reefs, enhancing biodiversity in the deep sea. Oil and gas-related activities have the potential to impact shipwreck sites. An estimated 30% of the oil from the Deepwater Horizon spill was deposited in the deep-sea, in areas that contain shipwrecks. We conducted field and laboratory experiments to determine if crude oil, dispersed oil, and/or dispersant affect the community composition, metabolic function, and/or corrosion potential of microorganisms inhabiting shipwrecks. Platforms containing carbon steel coupons (CSC) (n = 34 per platform) were placed at impacted and non-impacted shipwrecks or into four experimental microcosm tanks. After a 2-week acclimation period, tanks were treated with crude oil and/or dispersant or received no treatment. CSC and seawater (SW) samples for bacterial genetic analysis were collected bi-weekly (at 16 wks for field samples). Proteobacteria dominated field and lab CSC bacterial communities (77-97% of sequences). Field CSC bacterial communities differed at each wreck site (P = 0.001), with oil-impacted sites differing from control sites. Lab CSC bacterial communities differed between all treatment groups (P = 0.005) and changed over the course of the experiment (P = 0.001). CSC bacterial species richness, diversity, and dominance increased with time across all treatments indicating the recruitment and establishment of microbial biofilms on CSCs. SW bacterial communities differed between treatment groups (P = 0.001), with the dispersant treatment being most dissimilar from all other treatments (P < 0.01), and changed over time (P = 0.001). Oil- and oil/dispersant-treated CSCs exhibited higher corrosion compared to dispersant and control treatments. These findings indicate that exposure to oil and/or dispersant may alter bacterial community composition and corrosion potential.

Comparative toxicity of two oil dispersants to the early life stages of two marine species

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singer, M.M.; George, S.; Benner, D.

1993-10-01

Acute, flow-through, spiked-exposure toxicity tests were performed on the early life stages of two marine species using two oil dispersants. The species represent two common near-shore marine taxa: molluscs (red abalone, Haliotis rufescens) and crustaceans (kelp forest mysid, Holmesimysis costata). The dispersants were composed of complex mixtures of anionic and nonionic surfactants and solvents. The toxicity data showed that one dispersant, Slik-A-Way, was more toxic than the other, Nokomis[reg sign] 3, to both species. Median-effect concentration estimates for the two dispersants were significantly different between species. Slik-A-Way median-effect concentrations ranged from 16.8 to 23.9 initial ppm for Haliotis and 25.9more » to 34.6 initial ppm for Holmesimysis, whereas Nokomis[reg sign] 3 median-effect concentrations ranged from 21.0 to 24.0 initial ppm for Haliotis and from 118.0 to 123.2 initial ppm for Holmesimysis. Differences in toxicity seen in the two dispersants may be due to differences in surfactant formulations.« less

The effects of crude oil and the effectiveness of cleaner application following oiling on US Gulf of Mexico coastal marsh plants.

PubMed

Pezeshki, S R; DeLaune, R D; Jugsujinda, A

2001-01-01

Field studies were conducted in two different marsh habitats in Louisiana coastal wetlands to evaluate the effects of oiling (using South Louisiana Crude oil, SLC) and the effectiveness of a shoreline cleaner (COREXIT 9580) in removing oil from plant canopies. The study sites represented two major marsh habitats; the brackish marsh site was covered by Spartina patens and the freshwater marsh was covered by Sagittaria lancifolia. Field studies were conducted in each habitat using replicated 5.8 m2 plots that were subjected to three treatments; oiled only, oiled + cleaner (cleaner was used 2 days after oiling), and a control. Plant gas exchange responses, survival, growth, and biomass accumulation were measured. Results indicated that oiling led to rapid reductions in leaf gas exchange rates in both species. However, both species in 'oiled + cleaned' plots displayed improved leaf conductance and CO2 fixation rates. Twelve weeks after treatment initiation, photosynthetic carbon fixation in both species had recovered to normal levels. Over the short-term, S. patens showed more sensitivity to oiling with SLC than S. lancifolia as was evident from the data of the number of live shoots and above-ground biomass. Above-ground biomass remained significantly lower than control in S. patens under 'oiled' and 'oiled + cleaned' treatments while it was comparable to controls in S. lancifolia. These studies indicated that the cleaner removed oil from marsh grasses and alleviated the short-term impact of oil on gas exchange function of the study plants. However, use of cleaner had no detectable effects on above-ground biomass production or regeneration at the end of the first growing season in S. patens. Similarly, no beneficial effects of cleaner on carbon fixation and number of live shoots were apparent beyond 12 weeks in S. lancifolia.

Soybean-oil-based waterborne polyurethane dispersions: effects of polyol functionality and hard segment content on properties.

PubMed

Lu, Yongshang; Larock, Richard C

2008-11-01

The environmentally friendly vegetable-oil-based waterborne polyurethane dispersions with very promising properties have been successfully synthesized without difficulty from a series of methoxylated soybean oil polyols (MSOLs) with different hydroxyl functionalities ranging from 2.4 to as high as 4.0. The resulting soybean-oil-based waterborne polyurethane (SPU) dispersions exhibit a uniform particle size, which increases from about 12 to 130 nm diameter with an increase in the OH functionality of the MSOL from 2.4 to 4.0 and decreases with increasing content of the hard segments. The structure and thermophysical and mechanical properties of the resulting SPU films, which contain 50-60 wt % MSOL as renewable resources, have been studied by Fourier transform infrared spectroscopy, differential scanning calorimetry, dynamic mechanical analysis, thermogravimetric analysis, transmission electron microscopy, and mechanical testing. The experimental results reveal that the functionality of the MSOLs and the hard segment content play a key role in controlling the structure and the thermophysical and mechanical properties of the SPU films. These novel films exhibit tensile stress-strain behavior ranging from elastomeric polymers to rigid plastics and possess Young's moduli ranging from 8 to 720 MPa, ultimate tensile strengths ranging from 4.2 to 21.5 MPa, and percent elongation at break values ranging from 16 to 280%. This work has addressed concerns regarding gelation and higher cross-linking caused by the high functionality of vegetable-oil-based polyols. This article reports novel environmentally friendly biobased SPU materials with promising applications as decorative and protective coatings.

Toxicity of dispersant application: Biomarkers responses in gills of juvenile golden grey mullet (Liza aurata).

PubMed

Milinkovitch, Thomas; Godefroy, Joachim; Théron, Michaël; Thomas-Guyon, Hélène

2011-10-01

Dispersant use in nearshore areas is likely to increase the exposure of aquatic organisms to petroleum. To measure the toxicity of this controversial response technique, golden grey mullets (Liza aurata) were exposed to mechanically dispersed oil, chemically dispersed oil, dispersant alone in seawater, water-soluble fraction of oil and to seawater as a control treatment. Several biomarkers were assessed in the gills (enzymatic antioxidant activities, glutathione content, lipid peroxidation) and in the gallbladder (polycylic aromatic hydrocarbons metabolites). The significant differences between chemically dispersed oil and water soluble fraction of oil highlight the environmental risk to disperse an oil slick when containment and recovery can be conducted. The lack of significance between chemically and mechanically dispersed oil suggests that dispersant application is no more toxic than the natural dispersion of the oil slick. The results of this study are of interest in order to establish dispersant use policies in nearshore areas. Copyright © 2011 Elsevier Ltd. All rights reserved.

Crude Oil Spills and Health

MedlinePlus

... PubMed Health-Related Quality of Life in Older Coastal Residents After Multiple Disasters Modeling and evaluation of ... and TOXLINE references) Technical Product Bulletin - U.S. Environmental Protection Agency COREXIT® EC9527A (Formerly COREXIT 9527) ChemID - National ...

Starch-Soybean Oil Composites with High Oil: Starch Ratios Prepared by Steam Jet Cooking

USDA-ARS?s Scientific Manuscript database

Aqueous mixtures of soybean oil and starch were jet cooked at oil:starch ratios ranging from 0.5:1 to 4:1 to yield dispersions of micron-sized oil droplets that were coated with a thin layer of starch at the oil-water interface. The jet cooked dispersions were then centrifuged at 2060 and 10,800 x ...

Aquatic toxicity of petroleum products and dispersant agents determined under the U.S. EPA Oil Spill Research Program

EPA Science Inventory

The U.S. EPA Office of Research and Development has developed baseline data on the ecotoxicity of selected petroleum products and several chemical dispersants as part of its oil spills research program. Two diluted bitumens (dilbits) from the Alberta Tar Sands were tested for acu...

Method of refining cracked oil by using metallic soaps. [desulfurization of cracked oils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Masakichi, M.; Marunouchi, K.K.; Yoshimura, T.

1937-04-13

The method of refining cracked oil consists in dissolving oil-soluble heavy metallic soap of oleic acid in a volatile organic solvent which will disperse homogeneously in cracked oil; pouring the solution thus obtained slowly into cracked oil to effect dispersion naturally and homogeneously at room temperature in the cracked oil. This process serves to react the mercaptans in the cracked oil with the heavy metallic soap by a double decomposition reaction and to precipitate the mercaptans as insoluble metallic salts. The remaining liquid is distilled to separate it from the remaining solvent.

Aquatic toxicity of petroleum products and dispersant agents ...

EPA Pesticide Factsheets

The U.S. EPA Office of Research and Development has developed baseline data on the ecotoxicity of selected petroleum products and several chemical dispersants as part of its oil spills research program. Two diluted bitumens (dilbits) from the Alberta Tar Sands were tested for acute and chronic toxicity to standard freshwater and marine organisms given their spill potential during shipment within the United States. Separately, two reference crude oils representing a range of characteristics, and their mixtures with four representative dispersants, were tested to evaluate acute and chronic toxicity to marine organisms in support of Subpart J of the U.S. National Contingency Plan. Water accommodated fractions (WAF) of oil were prepared using traditional slow-stir methods and toxicity tests generally followed U.S. EPA standard effluent testing guidelines. WAFs were characterized for petroleum hydrocarbons including alkyl PAH homologs. The results of these studies will assist the U.S. EPA to assess toxicity data for unconventional oils (dilbits), and establish baseline toxicity data for selected crude oils and dispersant in support of planning and response activities. Abstract reporting the results of EPA's oil and dispersant toxicity testing program

Effects of dispersed oil on reproduction in the cold water copepod Calanus finmarchicus (Gunnerus)

PubMed Central

Olsen, Anders Johny; Nordtug, Trond; Altin, Dag; Lervik, Morten; Hansen, Bjørn Henrik

2013-01-01

Following a 120-h exposure period to 3 concentrations of oil dispersions (0.022 mg L−1, 1.8 mg L−1, and 16.5 mg L−1, plus controls) generated from a North Sea crude oil and a subsequent 21-d recovery, mortality, and several reproduction endpoints (egg production rates, egg hatching success, and fraction of females participating in reproduction) in Calanus finmarchicus were studied. Concentration-dependent mortality was found during exposure, averaging to 6%, 3%, 15%, and 42% for the controls and 3 exposure levels, respectively. At the start of the recovery period, mean egg production rates of surviving females from the highest concentrations were very low, but reproduction subsequently improved. In a 4-d single female reproduction test starting 13 d postexposure, no significant differences in egg production rates or hatching success were found between reproducing control and exposed copepods. However, a significantly lower portion of the surviving females from the highest exposure participated in egg production. The results indicate that although short-term exposure to oil-polluted water after an oil spill can induce severe mortality and temporarily suspend reproduction, copepods may recover and produce viable offspring soon after exposure. The results might imply that for C. finmarchicus populations, the impact from short-term exposure to an oil spill might be predicted from acute mortality and that delayed effects make only a limited contribution to population decrease. PMID:23661343

Determining The Dispersibility Of South Louisiana Crude Oil By Eight Oil Dispersant Products Listed On The NCP Product Schedule

EPA Science Inventory

We recently conducted a laboratory study to measure the dispersion effectiveness of eight dispersants currently listed on the National Contingency Plan Product Schedule. Results are useful in determining how many commercial dispersant products would have been effective for use o...

Bioaccumulation of polycyclic aromatic compounds: 1. Bioconcentration in two marine species and in semipermeable membrane devices during chronic exposure to dispersed crude oil.

PubMed

Baussant, T; Sanni, S; Jonsson, G; Skadsheim, A; Børseth, J F

2001-06-01

Assessing the fate in marine biota of hydrocarbons derived from oil particles that are discharged during exploration and production is of relevant environmental concern. However, a rather complex experimental setup is required to carry out such investigations. In this study, a sophisticated tool, the continuous-flow system (CFS), was used to mimic dispersed oil exposure to marine biota. Polycyclic aromatic hydrocarbon (PAH) uptake was studied in two species, the blue mussel Mytilus edulis and juvenile of the turbot Scophthalmus maximus, and in semipermeable membrane devices (SPMD) exposed to crude oil dispersed in a flow-through system. After an exposure period of 8 to 21 d, elimination in organisms and devices was analyzed for 9 to 10 d following transfer to PAH-free seawater. Principal component analysis (PCA) revealed different PAH patterns. In mussel and SPMD, the PAH profiles were very close to that analyzed in seawater. Slight differences were, however, indicated for large molecules with log Kow above six. Nonachievement of steady-state concentration and bioavailability of PAH in oil droplets may account for these differences. The PAH composition in fish revealed only congeners with two to three aromatic rings. A combination of bioavailability and efficient metabolism of the larger PAH molecules may explain this pattern. The CFS made possible a better understanding of some critical factors governing bioconcentration in marine biota from dispersed oil. Yet the results illustrate that uptake of PAH from exposure to oil particles is complex and that different species may bioconcentrate different molecules depending on factors like life style and metabolic capability to degrade the potential harmful substances. Hence, risk assessment of the actual impact of discharges to marine biota should consider these essential biological and ecological factors.

Novel pathways for injury from offshore oil spills: direct, sublethal and indirect effects of the Deepwater Horizon oil spill on pelagic Sargassum communities.

PubMed

Powers, Sean P; Hernandez, Frank J; Condon, Robert H; Drymon, J Marcus; Free, Christopher M

2013-01-01

The pelagic brown alga Sargassum forms an oasis of biodiversity and productivity in an otherwise featureless ocean surface. The vast pool of oil resulting from the Deepwater Horizon oil spill came into contact with a large portion of the Gulf of Mexico's floating Sargassum mats. Aerial surveys performed during and after the oil spill show compelling evidence of loss and subsequent recovery of Sargassum. Expanding on the trends observed in the aerial surveys, we conducted a series of mesocosm experiments to test the effect of oil and dispersants on the vertical position and weight of the Sargassum complex (Sargassum natans and S. fluitans), as well as on the dissolved oxygen concentrations surrounding the algae. Dispersant and dispersed-oil had significant effects on the vertical position of both species of Sargassum over a period of 72 hours. Similarly, dissolved oxygen concentrations were lowest in dispersant and dispersed-oil treatments, respectively. Cumulatively, our findings suggest three pathways for oil-spill related injury: (1) Sargassum accumulated oil on the surface exposing animals to high concentrations of contaminants; (2) application of dispersant sank Sargassum, thus removing the habitat and potentially transporting oil and dispersant vertically; and (3) low oxygen surrounded the habitat potentially stressing animals that reside in the alga. These pathways represent direct, sublethal, and indirect effects of oil and dispersant release that minimize the ecosystem services provided by floating Sargassum - the latter two effects are rarely considered in assessing impacts of oil spills or response procedures.

Novel Pathways for Injury from Offshore Oil Spills: Direct, Sublethal and Indirect Effects of the Deepwater Horizon Oil Spill on Pelagic Sargassum Communities

PubMed Central

Powers, Sean P.; Hernandez, Frank J.; Condon, Robert H.; Drymon, J. Marcus; Free, Christopher M.

2013-01-01

The pelagic brown alga Sargassum forms an oasis of biodiversity and productivity in an otherwise featureless ocean surface. The vast pool of oil resulting from the Deepwater Horizon oil spill came into contact with a large portion of the Gulf of Mexico’s floating Sargassum mats. Aerial surveys performed during and after the oil spill show compelling evidence of loss and subsequent recovery of Sargassum. Expanding on the trends observed in the aerial surveys, we conducted a series of mesocosm experiments to test the effect of oil and dispersants on the vertical position and weight of the Sargassum complex (Sargassum natans and S. fluitans), as well as on the dissolved oxygen concentrations surrounding the algae. Dispersant and dispersed-oil had significant effects on the vertical position of both species of Sargassum over a period of 72 hours. Similarly, dissolved oxygen concentrations were lowest in dispersant and dispersed-oil treatments, respectively. Cumulatively, our findings suggest three pathways for oil-spill related injury: (1) Sargassum accumulated oil on the surface exposing animals to high concentrations of contaminants; (2) application of dispersant sank Sargassum, thus removing the habitat and potentially transporting oil and dispersant vertically; and (3) low oxygen surrounded the habitat potentially stressing animals that reside in the alga. These pathways represent direct, sublethal, and indirect effects of oil and dispersant release that minimize the ecosystem services provided by floating Sargassum – the latter two effects are rarely considered in assessing impacts of oil spills or response procedures. PMID:24086378

Involvement of a plasmid in growth on and dispersion of crude oil by Acinetobacter calcoaceticus RA57.

PubMed Central

Rusansky, S; Avigad, R; Michaeli, S; Gutnick, D L

1987-01-01

A crude-oil-degrading Acinetobacter species, Acinetobacter calcoaceticus RA57, was isolated by standard enrichment culture techniques on the basis of its ability to utilize the oily sludge found in the vicinity of a local gas station. Strain RA57 was found to contain four plasmids: pSR1 (5.1 kilobases [kb]), pSR2 (5.4 kb), pSR3 (10.5 kb), and pSR4 (20 kb). Both supercoiled and open circular forms of the first three plasmids were identified by two-dimensional gel electrophoresis. Restriction endonuclease analysis of pSR4 demonstrated that the plasmid contained a circular map. Colonies were isolated at random after growth in the presence of acridine orange and found to fall into two categories: (i) those which had lost the ability to grow on and disperse crude oil in liquid culture and concurrently were cured of pSR4 and (ii) those which retained the ability to both grow on and disperse crude oil and which contained pSR4. Strains from the first class continued to grow on hydrocarbon vapors, indicating that the defect associated with the curing of pSR4 was related to the physical interaction of the cells with the hydrocarbon substrate, rather than to its metabolism. No differences in either adherence to hydrocarbons or production of extracellular emulsifying activity were found between the two classes of mutants. In growth experiments on crude oil in mixed culture with strains which either contained or lacked pSR4, no sparing of the growth defect was observed. The results are consistent with the possibility that pSR4 encodes a factor(s) which is tightly associated with the cell surface. Images PMID:2821903

Bioaccumulation of polycyclic aromatic compounds: 2. Modeling bioaccumulation in marine organisms chronically exposed to dispersed oil.

PubMed

Baussant, T; Sanni, S; Skadsheim, A; Jonsson, G; Børseth, J F; Gaudebert, B

2001-06-01

Within the frame of a large environmental study, we report on a research program that investigated the potential for bioaccumulation and subsequent effect responses in several marine organisms exposed to chronic levels of dispersed crude oil. Body burden can be estimated from kinetic parameters (rate constants for uptake and elimination), and appropriate body burden-effect relationships may improve assessments of environmental risks or the potential for such outcomes following chronic discharges at sea. We conducted a series of experiments in a flow-through system to describe the bioaccumulation kinetics of polycyclic aromatic hydrocarbons (PAH) at low concentrations of dispersed crude oils. Mussels (Mytilus edulis) and juvenile turbot (Scophthalmus maximus) were exposed for periods ranging from 8 to 21 d. Postexposure, the organisms were kept for a period of 9 to 10 d in running seawater to study elimination processes. Rate constants of uptake (k1) and elimination (k2) of the PAHs during and following exposure were calculated using a first-order kinetic model that assumed a decrease of the substances in the environment over time. The estimated bioconcentration factor was calculated from the ratio of k1/k2. The kinetic parameters of two-, three-, and four-ring PAHs in mussel and fish are compared with estimates based on hydrophobicity alone, expressed by the octanol-water partition coefficient, Kow (partitioning theory). A combination of reduced bioavailability of PAHs from oil droplets and degradation processes of PAHs in body tissues seems to explain discrepancies between kinetic rates based on Kow and actual kinetic rates measured in fish. Mussels showed a pattern more in compliance with the partitioning theory.

Poly(alkyl methacrylate) Brush-Grafted Silica Nanoparticles as Oil Lubricant Additives: Effects of Alkyl Pendant Groups on Oil Dispersibility, Stability, and Lubrication Property

DOE PAGES

Seymour, Bryan T.; Wright, Roger A. E.; Parrott, Alexander C.; ...

2017-07-03

This paper reports on the synthesis of a series of poly(alkyl methacrylate) brush-grafted, 23 nm silica nanoparticles (hairy NPs) and the study of the effect of alkyl pendant length on their use as oil lubricant additives for friction and wear reduction. The hairy NPs were prepared by surface-initiated reversible addition–fragmentation chain transfer polymerization from trithiocarbonate chain transfer agent (CTA)-functionalized silica NPs in the presence of a free CTA. We found that hairy NPs with sufficiently long alkyl pendant groups (containing >8 carbon atoms, such as 12, 13, 16, and 18 in this study) could be readily dispersed in poly(alphaolefin) (PAO),more » forming clear, homogeneous dispersions, and exhibited excellent stability at low and high temperatures as revealed by visual inspection and dynamic light scattering studies. Whereas poly(n-hexyl methacrylate) hairy NPs cannot be dispersed in PAO under ambient conditions or at 80 °C, interestingly, poly(2-ethylhexyl methacrylate) hairy NPs can be dispersed in PAO at 80 °C but not at room temperature, with a reversible clear-to-cloudy transition observed upon cooling. High-contact-stress ball-on-flat reciprocating sliding tribological tests at 100 °C showed significant reductions in both the coefficient of friction (up to 38%) and wear volume (up to 90% for iron flat) for transparent, homogeneous dispersions of hairy NPs in PAO at a concentration of 1.0 wt % compared with neat PAO. Finally, the formation of a load-bearing tribofilm at the rubbing interface was confirmed using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy.« less

Poly(alkyl methacrylate) Brush-Grafted Silica Nanoparticles as Oil Lubricant Additives: Effects of Alkyl Pendant Groups on Oil Dispersibility, Stability, and Lubrication Property

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seymour, Bryan T.; Wright, Roger A. E.; Parrott, Alexander C.

This paper reports on the synthesis of a series of poly(alkyl methacrylate) brush-grafted, 23 nm silica nanoparticles (hairy NPs) and the study of the effect of alkyl pendant length on their use as oil lubricant additives for friction and wear reduction. The hairy NPs were prepared by surface-initiated reversible addition–fragmentation chain transfer polymerization from trithiocarbonate chain transfer agent (CTA)-functionalized silica NPs in the presence of a free CTA. We found that hairy NPs with sufficiently long alkyl pendant groups (containing >8 carbon atoms, such as 12, 13, 16, and 18 in this study) could be readily dispersed in poly(alphaolefin) (PAO),more » forming clear, homogeneous dispersions, and exhibited excellent stability at low and high temperatures as revealed by visual inspection and dynamic light scattering studies. Whereas poly(n-hexyl methacrylate) hairy NPs cannot be dispersed in PAO under ambient conditions or at 80 °C, interestingly, poly(2-ethylhexyl methacrylate) hairy NPs can be dispersed in PAO at 80 °C but not at room temperature, with a reversible clear-to-cloudy transition observed upon cooling. High-contact-stress ball-on-flat reciprocating sliding tribological tests at 100 °C showed significant reductions in both the coefficient of friction (up to 38%) and wear volume (up to 90% for iron flat) for transparent, homogeneous dispersions of hairy NPs in PAO at a concentration of 1.0 wt % compared with neat PAO. Finally, the formation of a load-bearing tribofilm at the rubbing interface was confirmed using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy.« less

Hydrodeoxygenation of water-insoluble bio-oil to alkanes using a highly dispersed Pd-Mo catalyst.

PubMed

Duan, Haohong; Dong, Juncai; Gu, Xianrui; Peng, Yung-Kang; Chen, Wenxing; Issariyakul, Titipong; Myers, William K; Li, Meng-Jung; Yi, Ni; Kilpatrick, Alexander F R; Wang, Yu; Zheng, Xusheng; Ji, Shufang; Wang, Qian; Feng, Junting; Chen, Dongliang; Li, Yadong; Buffet, Jean-Charles; Liu, Haichao; Tsang, Shik Chi Edman; O'Hare, Dermot

2017-09-19

Bio-oil, produced by the destructive distillation of cheap and renewable lignocellulosic biomass, contains high energy density oligomers in the water-insoluble fraction that can be utilized for diesel and valuable fine chemicals productions. Here, we show an efficient hydrodeoxygenation catalyst that combines highly dispersed palladium and ultrafine molybdenum phosphate nanoparticles on silica. Using phenol as a model substrate this catalyst is 100% effective and 97.5% selective for hydrodeoxygenation to cyclohexane under mild conditions in a batch reaction; this catalyst also demonstrates regeneration ability in long-term continuous flow tests. Detailed investigations into the nature of the catalyst show that it combines hydrogenation activity of Pd and high density of both Brønsted and Lewis acid sites; we believe these are key features for efficient catalytic hydrodeoxygenation behavior. Using a wood and bark-derived feedstock, this catalyst performs hydrodeoxygenation of lignin, cellulose, and hemicellulose-derived oligomers into liquid alkanes with high efficiency and yield.Bio-oil is a potential major source of renewable fuels and chemicals. Here, the authors report a palladium-molybdenum mixed catalyst for the selective hydrodeoxygenation of water-insoluble bio-oil to mixtures of alkanes with high carbon yield.

Assessment of chemical dispersant effectiveness in a wave tank under regular non-breaking and breaking wave conditions.

PubMed

Li, Zhengkai; Lee, Kenneth; King, Thomas; Boufadel, Michel C; Venosa, Albert D

2008-05-01

Current chemical dispersant effectiveness tests for product selection are commonly performed with bench-scale testing apparatus. However, for the assessment of oil dispersant effectiveness under real sea state conditions, test protocols are required to have hydrodynamic conditions closer to the natural environment, including transport and dilution effects. To achieve this goal, Fisheries and Oceans Canada and the US Environmental Protection Agency (EPA) designed and constructed a wave tank system to study chemical dispersant effectiveness under controlled mixing energy conditions (regular non-breaking, spilling breaking, and plunging breaking waves). Quantification of oil dispersant effectiveness was based on observed changes in dispersed oil concentrations and oil-droplet size distribution. The study results quantitatively demonstrated that total dispersed oil concentration and breakup kinetics of oil droplets in the water column were strongly dependent on the presence of chemical dispersants and the influence of breaking waves. These data on the effectiveness of dispersants as a function of sea state will have significant implications in the drafting of future operational guidelines for dispersant use at sea.

Dispersant Effectiveness, In-Situ Droplet Size Distribution and ...

EPA Pesticide Factsheets

This report summarizes two projects covered under an Interagency Agreement between the Bureau of Safety and Environmental Enforcement (BSEE) and the U.S. Environmental Protection Agency (EPA) in collaboration with the Bedford Institute of Oceanography, Department of Fisheries and Oceans Canada (BIO DFO), New Jersey Institute of Technology (NJIT) and Dalhousie University. Both projects dovetail together in addressing the ability to differentiate physical from chemical dispersion effectiveness using dispersed oil simulations within a flume tank for improving forensic response monitoring tools. This report is split into separateTasks based upon the two projects funded by BSEE: 1) Dispersant Effectiveness, In-Situ Droplet Size Distribution and Numerical Modeling to Assess Subsurface Dispersant Injection as a Deepwater Blowout Oil Spill Response Option. 2) Evaluation of Oil Fluorescence Characteristics to Improve Forensic Response Tools. This report summarizes 2 collaborative projects funded through an Interagency Agreement with DOI BSEE and a Cooperative Agreement with DFO Canada. BSEE required that the projects be combined into one report as they are both covered under the one Interagency Agreement. Task B (Fluorescence of oils) is an SHC 3.62 FY16 product.

About Ganoderma boninense in oil palm plantations of Sumatra and peninsular Malaysia: Ancient population expansion, extensive gene flow and large scale dispersion ability.

PubMed

Mercière, Maxime; Boulord, Romain; Carasco-Lacombe, Catherine; Klopp, Christophe; Lee, Yang-Ping; Tan, Joon-Sheong; Syed Alwee, Sharifah S R; Zaremski, Alba; De Franqueville, Hubert; Breton, Frédéric; Camus-Kulandaivelu, Létizia

Wood rot fungi form one of the main classes of phytopathogenic fungus. The group includes many species, but has remained poorly studied. Many species belonging to the Ganoderma genus are well known for causing decay in a wide range of tree species around the world. Ganoderma boninense, causal agent of oil palm basal stem rot, is responsible for considerable yield losses in Southeast Asian oil palm plantations. In a large-scale sampling operation, 357 sporophores were collected from oil palm plantations spread over peninsular Malaysia and Sumatra and genotyped using 11 SSR markers. The genotyping of these samples made it possible to investigate the population structure and demographic history of G. boninense across the oldest known area of interaction between oil palm and G. boninense. Results show that G. boninense possesses a high degree of genetic diversity and no detectable genetic structure at the scale of Sumatra and peninsular Malaysia. The fact that few duplicate genotypes were found in several studies including this one supports the hypothesis of spore dispersal in the spread of G. boninense. Meanwhile, spatial autocorrelation analysis shows that G. boninense is able to disperse across both short and long distances. These results bring new insight into mechanisms by which G. boninense spreads in oil palm plantations. Finally, the use of approximate Bayesian computation (ABC) modelling indicates that G. boninense has undergone a demographic expansion in the past, probably before the oil palm was introduced into Southeast Asia. Copyright © 2017 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Comparative Risk Assessment of spill response options for a deepwater oil well blowout: Part 1. Oil spill modeling.

PubMed

French-McCay, Deborah; Crowley, Deborah; Rowe, Jill J; Bock, Michael; Robinson, Hilary; Wenning, Richard; Walker, Ann Hayward; Joeckel, John; Nedwed, Tim J; Parkerton, Thomas F

2018-06-01

Oil spill model simulations of a deepwater blowout in the Gulf of Mexico De Soto Canyon, assuming no intervention and various response options (i.e., subsea dispersant injection SSDI, in addition to mechanical recovery, in-situ burning, and surface dispersant application) were compared. Predicted oil fate, amount and area of surfaced oil, and exposure concentrations in the water column above potential effects thresholds were used as inputs to a Comparative Risk Assessment to identify response strategies that minimize long-term impacts. SSDI reduced human and wildlife exposure to volatile organic compounds; dispersed oil into a large water volume at depth; enhanced biodegradation; and reduced surface water, nearshore and shoreline exposure to floating oil and entrained/dissolved oil in the upper water column. Tradeoffs included increased oil exposures at depth. However, since organisms are less abundant below 200 m, results indicate that overall exposure of valued ecosystem components was minimized by use of SSDI. Copyright © 2018 Elsevier Ltd. All rights reserved.

Laboratory testing protocol for the impact of dispersed petrochemicals on seagrass.

PubMed

Wilson, K G; Ralph, P J

2012-11-01

To improve the effectiveness of oil spill mitigation, we developed a rapid, logistically simple protocol to detect petrochemical stress on seagrass. Sections of leaf blades from Zostera muelleri subsp. capricorni were exposed to the water accommodated fraction (WAF) of non-dispersed and dispersed Tapis crude oil and fuel oil (IFO-380) for 5h. Photosynthetic health was monitored by assessing changes in effective quantum yield of photosystem II (ΔF/F(m)(')) and chlorophyll a pigment concentrations. Loss of total petroleum hydrocarbons (TPH) was measured using an oil-in-water fluorometer, whilst GC-MS analyses quantified the hydrocarbon components within each treatment. Few significant differences were detected in the chlorophyll a pigment analyses; however, ΔF/F(m)(') appeared sensitive to petrochemical exposure. Dispersing both types of oil resulted in a substantial increase in the TPH of the WAF and was generally correlated with a greater physiological impact to the seagrass health, compared with the oil alone. Copyright © 2012 Elsevier Ltd. All rights reserved.

Marine Oil Biodegradation.

PubMed

Hazen, Terry C; Prince, Roger C; Mahmoudi, Nagissa

2016-03-01

Crude oil has been part of the marine environment for millions of years, and microbes that use its rich source of energy and carbon are found in seawater, sediments, and shorelines from the tropics to the polar regions. Catastrophic oil spills stimulate these organisms to "bloom" in a reproducible fashion, and although oil does not provide bioavailable nitrogen, phosphorus or iron, there are enough of these nutrients in the sea that when dispersed oil droplets dilute to low concentrations these low levels are adequate for microbial growth. Most of the hydrocarbons in dispersed oil are degraded in aerobic marine waters with a half-life of days to months. In contrast, oil that reaches shorelines is likely to be too concentrated, have lower levels of nutrients, and have a far longer residence time in the environment. Oil that becomes entrained in anaerobic sediments is also likely to have a long residence time, although it too will eventually be biodegraded. Thus, data that encompass everything from the ecosystem to the molecular level are needed for understanding the complicated process of petroleum biodegradation in marine environments.

A Study of the Effect of Surfactants on the Aggregation Behavior of Crude Oil Aqueous Dispersions through Steady-State Fluorescence Spectrometry.

PubMed

Vallejo-Cardona, Alba A; Cerón-Camacho, Ricardo; Karamath, James R; Martínez-Palou, Rafael; Aburto, Jorge

2017-07-01

Unconventional crude oil as heavy, extra heavy, bitumen, tight, and shale oils will meet 10% of worldwide needs for 2035, perhaps earlier. Petroleum companies will face problems concerning crude oil extraction, production, transport, and refining, and some of these are addressed by the use of surfactants and other chemicals. For example, water-in-crude oil emulsions are frequently found during the production of mature wells where enhanced recovery techniques have been deployed. Nevertheless, the selection of adequate surfactant, dosage, type of water (sea, tap or oilfield), kind of crude oil (light, heavy, extra heavy, tight, shale, bitumen) affect the effectivity of treatment and usual bottle tests give limited information. We developed a fluorescence technique to study the effect of surfactants on medium, heavy, and extra heavy crude oil employing the natural fluorophore molecules from petroleum. We first carried out the characterization of commercial and synthetic surfactants, then dispersions of petroleum in water were studied by steady-state fluorometry and the size of petroleum aggregates were measured. The aggregation of petroleum incremented from medium to extra heavy crude oil and we discussed the effect of different surfactants on such aggregation.

Evaluating Chemical Dispersant Efficacy In An Experimental Wave Tank: 1, Dispersant Effectiveness As A Function Of Energy Dissipation Rate

EPA Science Inventory

Numerous laboratory test systems have been developed for the comparison of efficacy between various chemical oil dispersant formulations. However, for the assessment of chemical dispersant effectiveness under realistic sea state, test protocols are required to produce hydrodynam...

Preparation of Microcapsules Containing β-Carotene with Thermo Sensitive Curdlan by Utilizing Reverse Dispersion

PubMed Central

Taguchi, Yoshinari; Ono, Fumiyasu; Tanaka, Masato

2013-01-01

We have tried to microencapsulate β-carotene with curdlan of a thermogelation type polysaccharide. Microcapsules were prepared by utilizing reverse dispersion, in which salada oil was the continuous phase (O’) and the curdlan water slurry (W) was the dispersed phase. β-carotene (O) as a core material was broken into fine oil droplets in the dispersed phase to form the (O/W) dispersion. The (O/W) dispersion was poured in the continuous phase (O’) and stirred to form the (O/W)/O’ dispersion at room temperature and then, temperature of the dispersion was raised to 80 °C to prepare curdlan-microcapusles containing β-carotene. In this microencapsulation process, the concentrations of curdlan and oil soluble surfactant and the impeller speed to form the (O/W)/O’ dispersion were mainly changed stepwise. We were able to prepare microcapsules by the microencapsulation method adopted here. The content of core material was increased with the curdlan concentration and decreased with the impeller speed and the oil soluble surfactant concentration. With the curdlan concentration, the drying rate of microcapsules was decreased and the retention ability for water was increased due to the stable preservation of β-carotene. PMID:24300565

MODELING METHODOLOGIES FOR OIL SPILLS

EPA Science Inventory

Oil spilled into aquatic environments is subject to a number of fates, including natural dispersion, emulsification and weathering. An oil slick moves due to the inherent spreading of the oil, currents, winds and waves. All of these processes influence the impacts of the oil on...

Optimized ultrasonic assisted extraction-dispersive liquid-liquid microextraction coupled with gas chromatography for determination of essential oil of Oliveria decumbens Vent.

PubMed

Sereshti, Hassan; Izadmanesh, Yahya; Samadi, Soheila

2011-07-22

Ultrasonic assisted extraction-dispersive liquid-liquid microextraction (UAE-DLLME) coupled with gas chromatography (GC) was applied for extraction and determination of essential oil constituents of the plant Oliveria decumbens Vent. Scanning electron microscopy (SEM) was used to see the effect of ultrasonic radiation on the extraction efficiency. By comparison with hydrodistillation, UAE-DLLME is fast, low cost, simple, efficient and consuming small amount of plant materials (∼1.0 g). The effects of various parameters such as temperature, ultrasonication time, volume of disperser and extraction solvents were investigated by a full factorial design to identify significant variables and their interactions. The results demonstrated that temperature and ultrasonication time had no considerable effect on the results. In the next step, a central composite design (CCD) was performed to obtain the optimum levels of significant parameters. The obtained optimal conditions were: 0.45 mL for disperser solvent (acetonitrile) and 94.84 μL for extraction solvent (chlorobenzene). The limits of detection (LODs), linear dynamic range and determination coefficients (R(2)) were 0.2-29 ng mL(-1), 1-2100 ng mL(-1) and 0.995-0.998, respectively. The main components of the essential oil were: thymol (47.06%), carvacrol (23.31%), gamma-terpinene (18.94%), p-cymene (8.71%), limonene (0.76%) and myristicin (0.63%). Copyright © 2011 Elsevier B.V. All rights reserved.

Marine Oil Biodegradation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hazen, Terry C.; Prince, Roger; Mahmoudi, Nagissa

Crude oil has been part of the marine environment for millions of years, and microbes that use its rich source of energy and carbon are found in seawater, sediments and shorelines from the tropics to the polar regions. Catastrophic oil spills stimulate these organisms to ‘bloom’ in a reproducible fashion, and although oil does not provide bioavailable nitrogen, phosphorus or iron, there are enough of these nutrients in the sea that when dispersed oil droplets dilute to low concentrations these low levels are adequate for microbial growth. Most of the hydrocarbons in dispersed oil are degraded in aerobic marine watersmore » with a half-life of days to months. In contrast, oil that reaches shorelines is likely to be too concentrated, have lower levels of nutrients, and have a far longer residence time in the environment. Oil that becomes entrained in anaerobic sediments is also likely to have a long residence time, although it too will eventually be biodegraded. Thus, data that encompass everything from the ecosystem to the molecular level are needed for understanding the complicated process of petroleum biodegradation in marine environments.« less

Marine Oil Biodegradation

DOE PAGES

Hazen, Terry C.; Prince, Roger; Mahmoudi, Nagissa

2015-12-23

Crude oil has been part of the marine environment for millions of years, and microbes that use its rich source of energy and carbon are found in seawater, sediments and shorelines from the tropics to the polar regions. Catastrophic oil spills stimulate these organisms to ‘bloom’ in a reproducible fashion, and although oil does not provide bioavailable nitrogen, phosphorus or iron, there are enough of these nutrients in the sea that when dispersed oil droplets dilute to low concentrations these low levels are adequate for microbial growth. Most of the hydrocarbons in dispersed oil are degraded in aerobic marine watersmore » with a half-life of days to months. In contrast, oil that reaches shorelines is likely to be too concentrated, have lower levels of nutrients, and have a far longer residence time in the environment. Oil that becomes entrained in anaerobic sediments is also likely to have a long residence time, although it too will eventually be biodegraded. Thus, data that encompass everything from the ecosystem to the molecular level are needed for understanding the complicated process of petroleum biodegradation in marine environments.« less

Impact of oil in the tropical marine environment. Technical pub

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cintron, G.; Lugo, A.E.; Martinez, R.

1981-11-01

Oil spills have a devastating effect on biologically rich coastal environments. This report investigates this problem, covering damage by oil to biological systems, the use of dispersants (toxicity and considerations for dispersant use), impact of oil and dispersants on coral reefs, impact of oil on seagrass beds and sandy beaches, impact of oil on mangroves (seedling survival and tolerance, regeneration, forest type vulnerability, and cleanup and recovery activities in mangroves), conclusions, and recommendations. The study concludes that coral reefs and seagrass beds may escape significant spill damage if pollution is not chronic and if dispersants are not used. Sandy andmore » rocky shores may be severely impacted but recover quickly. Mangroves are the most vulnerable coastal ecosystem. Recommendations are that oil spill contingency plans must be prepared for all areas, and that the necessary equipment for the plans must be in place.« less

Method of dispersing a hydrocarbon using bacteria

DOEpatents

Tyndall, R.L.

1996-09-24

A new protozoan derived microbial consortia and method for their isolation are provided. The isolated consortia and bacteria are useful for treating wastes such as trichloroethylene and trinitrotoluene. The isolated consortia, bacteria, and dispersants are useful for dispersing hydrocarbons such as oil, creosote, wax, and grease.

Method of dispersing a hydrocarbon using bacteria

DOEpatents

Tyndall, Richard L.

1996-01-01

New protozoan derived microbial consortia and method for their isolation are provided. Consortia and bacteria isolated therefrom are useful for treating wastes such as trichloroethylene and trinitrotoluene. Consortia, bacteria isolated therefrom, and dispersants isolated therefrom are useful for dispersing hydrocarbons such as oil, creosote, wax, and grease.

Modelling and assessment of accidental oil release from damaged subsea pipelines.

PubMed

Li, Xinhong; Chen, Guoming; Zhu, Hongwei

2017-10-15

This paper develops a 3D, transient, mathematical model to estimate the oil release rate and simulate the oil dispersion behavior. The Euler-Euler method is used to estimate the subsea oil release rate, while the Eulerian-Lagrangian method is employed to track the migration trajectory of oil droplets. This model accounts for the quantitative effect of backpressure and hole size on oil release rate, and the influence of oil release rate, oil density, current speed, water depth and leakage position on oil migration is also investigated in this paper. Eventually, the results, e.g. transient release rate of oil, the rise time of oil and dispersion distance are determined by above-mentioned model, and the oil release and dispersion behavior under different scenarios is revealed. Essentially, the assessment results could provide a useful guidance for detection of leakage positon and placement of oil containment boom. Copyright © 2017 Elsevier Ltd. All rights reserved.

Helping nature clean up oil spills

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paddock, A.

Oil spills are nothing new. In fact, for millions of years crude oil has been seeping up to the Earth`s surface, and for all that time Mother Nature has been on the job with microbes, or bacteria, to harmlessly convert the oil to water and carbon dioxide gas. Not all bacteria are bad. True, some can make us sick, however, the good ones help us bake bread, brew beer, and even clean up oil spills by a process known as biodegradation. Oil and bacteria don`t easily get together because oil and water don`t mix and bacteria prefer to stay inmore » water. After some oil tankers spills in the English Channel 25 years ago, major oil companies (Arco, BP, Exxon, and others) developed oil dispersant products-specialized chemicals that make oils and sea water mix. The simplest examples of similar wetting agents are soaps and detergents. Now, thanks to dispersants, the natural bacteria at sea can easily get to the oil and the normally slow biodegradation process goes rather quickly.« less

Valve gape behaviour of mussels (Mytilus edulis) exposed to dispersed crude oil as an environmental monitoring endpoint.

PubMed

Redmond, Kirsten J; Berry, Mark; Pampanin, Daniela M; Andersen, Odd Ketil

2017-04-15

Environmental monitoring requires cost-effective and efficient methods for detecting potential effects of pollution, and valve gape behaviour has been used with this purpose for a range of contaminants in freshwater and marine bivalves. The current study investigated the use of a new method for measuring valve behaviour responses in mussels (Mytilus edulis) exposed to dispersed crude oil (DCO). Results confirmed that valve gape is a sensitive parameter; at the high DCO concentration (0.25mgL -1 ) the mean valve gape was reduced from 49 to 31%, and mussels increased shell movement (measured as distance travelled) or spent more time closed to avoid contact with the oil. At the low DCO concentration (0.015mgL -1 ) the distance travelled parameter was the most sensitive endpoint. Results also demonstrated that valve gape behaviour is a valid endpoint when monitoring mussels for exposure to DCO. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effectiveness of the Surfactant Dioctyl Sodium Sulfosuccinate (DOSS) to Disperse Oil in a Changing Marine Environment

NASA Astrophysics Data System (ADS)

Steffy, D. A.; Nichols, A.; Kiplagat, G.

2011-12-01

We investigated the surfactant which was used to disperse the oil spill which occurred in the Gulf of Mexico during the summer 2010. The surfactant DOSS is an organic sulfonic acid salt which is a synthetic detergent that disrupts the interfacial tension between the saltwater and crude oil phases. The disruption becomes maximum at or above the critical micelle concentration (CMC). The CMC for the surfactant was determined to be at 0.13 % solution in deionized water at a pH of 7.2 and a temperature of 70oF. The CMC is lower at 0.09% solution in salt water. The effect has been identified as a "salting out" effect (Somasundaran, 2006). The CMC of DOSS in both saline and deionized water occurred at lower percent solutions at higher temperatures. The surface tension versus % solution plots are modeled by a power equation, with correlation coefficients consistently over 0.94. Surface tension versus percent solution plots are scalable to fit a temperature desired by the function f(x)= (1/(1+X^α)), where α = T1/T2.

Optimisation of dispersion parameters of Gaussian plume model for CO₂ dispersion.

PubMed

Liu, Xiong; Godbole, Ajit; Lu, Cheng; Michal, Guillaume; Venton, Philip

2015-11-01

The carbon capture and storage (CCS) and enhanced oil recovery (EOR) projects entail the possibility of accidental release of carbon dioxide (CO2) into the atmosphere. To quantify the spread of CO2 following such release, the 'Gaussian' dispersion model is often used to estimate the resulting CO2 concentration levels in the surroundings. The Gaussian model enables quick estimates of the concentration levels. However, the traditionally recommended values of the 'dispersion parameters' in the Gaussian model may not be directly applicable to CO2 dispersion. This paper presents an optimisation technique to obtain the dispersion parameters in order to achieve a quick estimation of CO2 concentration levels in the atmosphere following CO2 blowouts. The optimised dispersion parameters enable the Gaussian model to produce quick estimates of CO2 concentration levels, precluding the necessity to set up and run much more complicated models. Computational fluid dynamics (CFD) models were employed to produce reference CO2 dispersion profiles in various atmospheric stability classes (ASC), different 'source strengths' and degrees of ground roughness. The performance of the CFD models was validated against the 'Kit Fox' field measurements, involving dispersion over a flat horizontal terrain, both with low and high roughness regions. An optimisation model employing a genetic algorithm (GA) to determine the best dispersion parameters in the Gaussian plume model was set up. Optimum values of the dispersion parameters for different ASCs that can be used in the Gaussian plume model for predicting CO2 dispersion were obtained.

Exposure to crude oil micro-droplets causes reduced food uptake in copepods associated with alteration in their metabolic profiles.

PubMed

Hansen, Bjørn Henrik; Altin, Dag; Nordtug, Trond; Øverjordet, Ida Beathe; Olsen, Anders J; Krause, Dan; Størdal, Ingvild; Størseth, Trond R

2017-03-01

Acute oil spills and produced water discharges may cause exposure of filter-feeding pelagic organisms to micron-sized dispersed oil droplets. The dissolved oil components are expected to be the main driver for oil dispersion toxicity; however, very few studies have investigated the specific contribution of oil droplets to toxicity. In the present work, the contribution of oil micro-droplet toxicity in dispersions was isolated by comparing exposures to oil dispersions (water soluble fraction with droplets) to concurrent exposure to filtered dispersions (water-soluble fractions without droplets). Physical (coloration) and behavioral (feeding activity) as well as molecular (metabolite profiling) responses to oil exposures in the copepod Calanus finmarchicus were studied. At high dispersion concentrations (4.1-5.6mg oil/L), copepods displayed carapace discoloration and reduced swimming activity. Reduced feeding activity, measured as algae uptake, gut filling and fecal pellet production, was evident also for lower concentrations (0.08mg oil/L). Alterations in metabolic profiles were also observed following exposure to oil dispersions. The pattern of responses were similar between two comparable experiments with different oil types, suggesting responses to be non-oil type specific. Furthermore, oil micro-droplets appear to contribute to some of the observed effects triggering a starvation-type response, manifested as a reduction in metabolite (homarine, acetylcholine, creatine and lactate) concentrations in copepods. Our work clearly displays a relationship between crude oil micro-droplet exposure and reduced uptake of algae in copepods. Copyright © 2017 Elsevier B.V. All rights reserved.

Dual dispersive liquid-liquid microextraction for determination of phenylpropenes in oils by gas chromatography-mass spectrometry.

PubMed

Tsai, Chia-Ju; Li, Jih-Heng; Feng, Chia-Hsien

2015-09-04

A novel, simple and quick sample preparation method was developed and used for pre-concentration and extraction of six phenylpropenes, including anethole, estragole, eugenol, methyl eugenol, safrole and myristicin, from oil samples by dual dispersive liquid-liquid microextraction. Gas chromatography-mass spectrometry was used for determination and separation of compounds. Several experimental parameters affecting extraction efficiency were evaluated and optimized, including forward-extractant type and volume, surfactant type and concentration, water volume, and back-extractant type and volume. For all analytes (10-1000ng/mL), the limits of detection (S/N≧3) ranged from 1.0 to 3.0ng/mL; the limits of quantification (S/N≧10) ranged from 2.5 to 10.0ng/mL; and enrichment factors ranged from 3.2 to 37.1 times. Within-run and between-run relative standard deviations (n=6) were less than 2.61% and less than 4.33%, respectively. Linearity was excellent with determination coefficients (r(2)) above 0.9977. The experiments showed that the proposed method is a simple, effective, and environmentally friendly method of analyzing phenylpropenes in oil samples. Copyright © 2015 Elsevier B.V. All rights reserved.

Optimization of an accelerated solvent extraction dispersive liquid-liquid microextraction method for the separation and determination of essential oil from Ligusticum chuanxiong Hort by gas chromatography with mass spectrometry.

PubMed

Yang, Guang; Sun, Qiushi; Hu, Zhiyan; Liu, Hua; Zhou, Tingting; Fan, Guorong

2015-10-01

In this study, an accelerated solvent extraction dispersive liquid-liquid microextraction coupled with gas chromatography and mass spectrometry was established and employed for the extraction, concentration and analysis of essential oil constituents from Ligusticum chuanxiong Hort. Response surface methodology was performed to optimize the key parameters in accelerated solvent extraction on the extraction efficiency, and key parameters in dispersive liquid-liquid microextraction were discussed as well. Two representative constituents in Ligusticum chuanxiong Hort, (Z)-ligustilide and n-butylphthalide, were quantitatively analyzed. It was shown that the qualitative result of the accelerated solvent extraction dispersive liquid-liquid microextraction approach was in good agreement with that of hydro-distillation, whereas the proposed approach took far less extraction time (30 min), consumed less plant material (usually <1 g, 0.01 g for this study) and solvent (<20 mL) than the conventional system. To sum up, the proposed method could be recommended as a new approach in the extraction and analysis of essential oil. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A literature review of portable fluorescence-based oil-in-water monitors.

PubMed

Lambert, P

2003-08-15

The results of a literature search on fluorescence-based portable detectors to measure the real-time concentration of oil are reported. For more than two decades, fluorometers have been commonly employed to monitor dispersed oil levels at oil spills on water. The focus of this paper has been to extract specific information from references about how the instruments were used, including set up and calibration procedures, the oil and dispersant measured, the approximate concentration range of the oil in the water column, and how the real-time data compared to traditional laboratory techniques.

The formation process and responsive impacts of single oil droplet in submerged process.

PubMed

Li, Haoshuai; Meng, Long; Shen, Tiantian; Zhang, Jianrui; Bao, Mutai; Sun, Peiyan

2017-11-15

Simulated column was applied to research forming progress of single oil droplet in submerged process, floating progress, and study effects of environment factors and dispersants on the concentration of oil hydrocarbon in water as well as changing rules of oil droplet sizes. As expected, particular formation mechanism of single oil droplet was presented. When necking down length L is 0.5 time of oil droplet diameter (d) after expansion phase, necking down becomes long and thin; when L=2d, necking down begins to break. In floating progress, the shape changes oval and its motion trail becomes an auger-type. Fluctuation occurs at horizontal direction. Dispersants decrease oil droplet size by its dispersion effect, and cut down effect of Van Der Waals force among oil droplets. More broadly, these findings provide rare empirical evidence expounding formation mechanism of single oil droplet to increasing ability of oil spill response. Copyright © 2017 Elsevier Ltd. All rights reserved.

Polymeric nanospheres as a displacement fluid in enhanced oil recovery

NASA Astrophysics Data System (ADS)

Hendraningrat, Luky; Zhang, Julien

2015-12-01

This paper presents the investigation of using nanoscale polyacrylamide-based spheres (nanospheres) as a displacement fluid in enhanced oil recovery (EOR). Coreflood experiments were conducted to evaluate the impact of nanospheres and its concentration dispersed in model formation water on oil recovery during a tertiary oil recovery process. The coreflood results showed that nanospheres can enhance residual oil recovery in the sandstone rock samples and its concentration showed a significant impact into incremental oil. By evaluating the contact angle, it was observed that wettability alteration also might be involved in the possible oil displacement mechanism in this process together with fluid behavior and permeability to water that might divert injected fluid into unswept oil areas and enhance the residual oil recovery. These investigations promote nanospheres aqueous disperse solution as a potential displacement fluid in EOR.

Solubilization of Tea Seed Oil in a Food-Grade Water-Dilutable Microemulsion

PubMed Central

Deng, Lingli; Que, Fei; Wei, Hewen; Xu, Guangwei; Dong, Xiaowei; Zhang, Hui

2015-01-01

Food-grade microemulsions containing oleic acid, ethanol, Tween 20, and water were formulated as a carrier system for tea seed oil (Camellia oleifera Abel.). The effect of ethanol on the phase behavior of the microemulsion system was clearly reflected in pseudo-ternary diagrams. The solubilization capacity and solubilization efficiency of tea seed oil dispersions were measured along the dilution line at a 70/30 surfactant/oil mass ratio with Tween 20 as the surfactant and oleic acid and ethanol (1:3, w/w) as the oil phase. The dispersed phase of the microemulsion (1.5% weight ratio of tea seed oil to the total amount of oil, surfactant, and tea seed oil) could be fully diluted with water without phase separation. Differential scanning calorimetry and viscosity measurements indicated that both the carrier and solubilized systems underwent a similar microstructure transition upon dilution. The dispersion phases gradually inverted from the water-in-oil phase (< 35% water) to the bicontinuous phase (40–45% water) and finally to the oil-in-water phase (> 45% water) along the dilution line. PMID:25996147

Solubilization of tea seed oil in a food-grade water-dilutable microemulsion.

PubMed

Deng, Lingli; Que, Fei; Wei, Hewen; Xu, Guangwei; Dong, Xiaowei; Zhang, Hui

2015-01-01

Food-grade microemulsions containing oleic acid, ethanol, Tween 20, and water were formulated as a carrier system for tea seed oil (Camellia oleifera Abel.). The effect of ethanol on the phase behavior of the microemulsion system was clearly reflected in pseudo-ternary diagrams. The solubilization capacity and solubilization efficiency of tea seed oil dispersions were measured along the dilution line at a 70/30 surfactant/oil mass ratio with Tween 20 as the surfactant and oleic acid and ethanol (1:3, w/w) as the oil phase. The dispersed phase of the microemulsion (1.5% weight ratio of tea seed oil to the total amount of oil, surfactant, and tea seed oil) could be fully diluted with water without phase separation. Differential scanning calorimetry and viscosity measurements indicated that both the carrier and solubilized systems underwent a similar microstructure transition upon dilution. The dispersion phases gradually inverted from the water-in-oil phase (< 35% water) to the bicontinuous phase (40-45% water) and finally to the oil-in-water phase (> 45% water) along the dilution line.

Mitigating oil spills in the water column

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barry, Edward; Libera, Joseph A.; Mane, Anil U.

The scale and scope of uncontrolled oil spills can be devastating. Diverse marine environments and fragile ecologies are some of the most susceptible to the many ill effects, while the economic costs can be crippling. A notoriously difficult challenge with no known technological solution is the successful removal of oil dispersed in the water column. Here, we address this problem through cheap and reusable oil sorbents based on the chemical modification of polymer foams. Interfacial chemistry was optimized and subsequently tested in a simulated marine environment at the National Oil Spill Response Research & Renewable Energy Test Facility, Ohmsett. Wemore » find favorable performance for surface oil mitigation and, for the first time, demonstrate the advanced sorbent's efficiency and efficacy at pilot scale in extraction of crude oil and refined petroleum products dispersed in the water column. As a result, this is a potentially disruptive technology, opening a new field of environmental science focused on sub-surface pollutant sequestration.« less

Mitigating oil spills in the water column

DOE PAGES

Barry, Edward; Libera, Joseph A.; Mane, Anil U.; ...

2017-10-05

The scale and scope of uncontrolled oil spills can be devastating. Diverse marine environments and fragile ecologies are some of the most susceptible to the many ill effects, while the economic costs can be crippling. A notoriously difficult challenge with no known technological solution is the successful removal of oil dispersed in the water column. Here, we address this problem through cheap and reusable oil sorbents based on the chemical modification of polymer foams. Interfacial chemistry was optimized and subsequently tested in a simulated marine environment at the National Oil Spill Response Research & Renewable Energy Test Facility, Ohmsett. Wemore » find favorable performance for surface oil mitigation and, for the first time, demonstrate the advanced sorbent's efficiency and efficacy at pilot scale in extraction of crude oil and refined petroleum products dispersed in the water column. As a result, this is a potentially disruptive technology, opening a new field of environmental science focused on sub-surface pollutant sequestration.« less

Oil mixing behavior after an oil spill: identification conflicts of different fingerprints.

PubMed

He, Shijie; Yu, Hongjun; Luo, Yongming; Wang, Chuanyuan; Li, Xueshuang; Li, Zhongping

2018-04-01

Clearing up whether spilled oil is mixed or not can strengthen the accuracy of oil spill identification. In the present study, the biomarkers in spilled oil samples were detected. The weathering modes of different types of diagnostic ratio and carbon isotope values of individual n-alkanes were also analyzed. The results showed that the diagnostic ratios of steroids, terpenes and aromatics, and weathering characteristics of carbon isotope composition (δ 13 C) of individual n-alkanes supported the idea that Dalian oil spill emerged from a single oil source. Furthermore, commonly used diagnostic ratios of n-alkanes indicated that the Dalian oil spill had undergone the oil mixing process. The different identifying outcomes indicate that some kinds of n-alkane-rich substance (such as oil dispersants) were mixed in the Dalian spilled oil and interfered with the routine diagnosis ratios of n-alkanes.

Rapid determination of hydrophilic phenols in olive oil by vortex-assisted reversed-phase dispersive liquid-liquid microextraction and screen-printed carbon electrodes.

PubMed

Fernández, Elena; Vidal, Lorena; Canals, Antonio

2018-05-01

A novel approach is presented to determine hydrophilic phenols in olive oil samples, employing vortex-assisted reversed-phase dispersive liquid-liquid microextraction (RP-DLLME) for sample preparation and screen-printed carbon electrodes for voltammetric analysis. The oxidation of oleuropein, hydroxytyrosol, caffeic acid, ferulic acid and tyrosol was investigated, being caffeic acid and tyrosol selected for quantification. A matrix-matching calibration using sunflower oil as analyte-free sample diluted with hexane was employed to compensate matrix effects. Samples were analyzed under optimized RP-DLLME conditions, i.e., extractant phase, 1M HCl; extractant volume, 100µL; extraction time, 2min; centrifugation time, 10min; centrifugation speed, 4000rpm. The working range showed a good linearity between 0.075 and 2.5mgL -1 (r = 0.998, N = 7) for caffeic acid, and between 0.075 and 3mgL -1 (r = 0.999, N = 8) for tyrosol. The methodological limit of detection was empirically established at 0.022mgL -1 for both analytes, which is significantly lower than average contents found in olive oil samples. The repeatability was evaluated at two different spiking levels (i.e., 0.5mgL -1 and 2mgL -1 ) and coefficients of variation ranged from 8% to 11% (n = 5). The applicability of the proposed method was tested in olive oil samples of different quality (i.e., refined olive oil, virgin olive oil and extra virgin olive oil). Relative recoveries varied between 83% and 108% showing negligible matrix effects. Finally, fifteen samples were analyzed by the proposed method and a high correlation with the traditional Folin-Ciocalteu spectrophotometric method was obtained. Thereafter, the concentrations of the fifteen oil samples were employed as input variables in linear discriminant analysis in order to distinguish between olive oils of different quality. Copyright © 2017 Elsevier B.V. All rights reserved.

Experimental study of oil plume stability: Parametric dependences and optimization.

PubMed

Li, Haoshuai; Shen, Tiantian; Bao, Mutai

2016-10-15

Oil plume is known to interact with density layer in spilled oil. Previous studies mainly focused on tracking oil plumes and predicting their impact on marine environment. Here, simulated experiments are presented that investigated the conditions inducing the formation of oil plume, focusing especially on the effects of oil/water volume ratio, oil/dispersant volume rate, ambient stratification and optimal conditions of oil plume on determining whether a plume will trap or escape. Scenario simulations showed that OWR influences the residence time most, dispersants dosage comes second and salinity least. The optimum residence time starts from 2387s, occurred at approximately condition (OWR, 0.1, DOR, 25.53% and salinity, 32.38). No change in the relative distribution under the more scale tank was observed, indicating these provide the time evolution of the oil plumes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Solid lipid dispersions: potential delivery system for functional ingredients in foods.

PubMed

Asumadu-Mensah, Aboagyewa; Smith, Kevin W; Ribeiro, Henelyta S

2013-07-01

Structured solid lipid (SL) systems have the advantages of long-term physical stability, low surfactant concentrations, and may exhibit controlled release of active ingredients. In this research work, the potential use of high-melting SLs for the production of the above structured SL carrier systems was investigated. Dispersions containing either SL or blend of solid lipid and oil (SL+O) were produced by a hot melt high-pressure homogenization method. Experiments involved the use of 3 different SLs for the disperse phase: stearic acid, candelilla wax and carnauba wax. Sunflower oil was incorporated in the disperse phase for the production of the dispersions containing lipid and oil. In order to evaluate the practical aspects of structured particles, analytical techniques were used including: static light scattering to measure particle sizes, transmission electron microscopy (TEM) for investigating particle morphology and differential scanning calorimetry (DSC) to investigate the crystallization behavior of lipids in bulk and in dispersions. Results showed different mean particle sizes depending on the type of lipid used in the disperse phase. Particle sizes for the 3 lipids were: stearic acid (SL: 195 ± 2.5 nm; SL+O: 138 ± 6.0 nm); candelilla wax (SL: 178 ± 1.7 nm; SL+O: 144 ± 0.6 nm); carnauba wax (SL: 303 ± 1.5 nm; SL+O: 295 ± 5.0 nm). TEM results gave an insight into the practical morphology, showing plate-like and needle-like structures. DSC investigations also revealed that SL dispersions melted and crystallized at lower temperatures than the bulk. This decrease can be explained by the small particle sizes of the dispersion, the high-specific surface area, and the presence of a surfactant. © 2013 Institute of Food Technologists®

The Rate of Crude Oil Biodegradation in the Sea.

PubMed

Prince, Roger C; Butler, Josh D; Redman, Aaron D

2017-02-07

Various groups have studied the rate of oil biodegradation in the sea over many years, but with no consensus on results. This can be attributed to many factors, but we show here that the principal confounding influence is the concentration of oil used in different experiments. Because of dilution, measured concentrations of dispersed oil in the sea are sub-parts-per-million within a day of dispersal, and at such concentrations the rate of biodegradation of detectable oil hydrocarbons has an apparent half-life of 7-14 days. This can be contrasted with the rate of degradation at the higher concentrations found in oil slicks or when stranded on a shoreline; there the apparent half-life varies from many months to many years.

EVALUATION OF MIXING ENERGY IN FLASKS USED FOR DISPERSANT EFFECTIVENESS TESTING

EPA Science Inventory

A U.S. Environmental Protection Agency (EPA) laboratory screening protocol for dispersant effectiveness consists of placing water, oil, and a dispersant in a flask and mixing the contents on an orbital shaker. Two flasks are being investigated, a simple Erlenmeyer (used in EPA's...

The Physical State of Emulsified Edible Oil Modulates Its in Vitro Digestion.

PubMed

Guo, Qing; Bellissimo, Nick; Rousseau, Dérick

2017-10-18

Emulsified lipid digestion was tailored by manipulating the physical state of dispersed oil droplets in whey protein stabilized oil-in-water (O/W) emulsions, where the oil phase consisted of one of five ratios of soybean oil (SO) and fully hydrogenated soybean oil (FHSO). The evolution in particle size distribution, structural changes during oral, gastric, and intestinal digestion, and free fatty acid release during intestinal digestion were all investigated. Irrespective of the physical state and structure of the dispersed oil/fat, all emulsions were stable against droplet size increases during oral digestion. During gastric digestion, the 50:50 SO:FHSO emulsion was more stable against physical breakdown than any other emulsion. All emulsions underwent flocculation and coalescence or partial coalescence upon intestinal digestion, with the SO emulsion being hydrolyzed the most rapidly. The melting point of all emulsions containing FHSO was above 37 °C, with the presence of solid fat within the dispersed oil droplets greatly limiting lipolysis. Fat crystal polymorph and nanoplatelet size did not play an important role in the rate and extent of lipid digestion. Free fatty acid release modeled by the Weibull distribution function showed that the rate of lipid digestion (κ) decreased with increasing solid fat content, and followed an exponential relationship (R 2 = 0.95). Overall, lipid digestion was heavily altered by the physical state of the dispersed oil phase within O/W emulsions.

Verification by Remote Sensing of an Oil Slick Movement Prediction Model

NASA Technical Reports Server (NTRS)

Klemas, V. (Principal Investigator); Davis, G.; Wang, H.

1975-01-01

The author has identified the following significant results. LANDSAT, aircraft, ships, and air-dropped current drogues were deployed to determine current circulation and to track oil slick movement on four different dates in Delaware Bay. Results were used to verify a predictive model for oil slick movement and dispersion. The model predicts the behavior of oil slicks given their size, location, tidal stage (current), weather (wind), and nature of crude. Both LANDSAT satellites provided valuable data on gross circulation patterns and convergent coastal fronts which by capturing oil slicks significantly influence their movement and dispersion.

Numerical 3D modelling of oil dispersion in the sea due to different accident scenarios

NASA Astrophysics Data System (ADS)

Guandalini, Roberto; Agate, Giordano; Moia, Fabio

2017-04-01

The purpose of the study has been the development of a methodology, based on a numerical 3D approach, for the analysis of oil dispersion in the sea, in order to simulate with a high level of accuracy the dynamic behavior of the oil plume and its displacement in the environment. As a matter of fact, the numerical simulation is the only approach currently able to analyse in detail possible accident scenarios, even with an high degree of complexity, of different type and intensity, allowing to follow their evolution both in time and space, and to evaluate the effectiveness of suggested prevention or recovery actions. The software for these calculations is therefore an essential tool in order to simulate the impact effects in the short, medium and long period, able to account for the complexity of the sea system involved in the dispersion process and its dependency on the meteorological, marine and morphological local conditions. This software, generally based on fluid dynamic 3D simulators and modellers, is therefore extremely specialized and requires expertise for an appropriate usage, but at the same time it allows detailed scenario analyses and design verifications. It takes into account different parameters as the sea current field and its turbulence, the wind acting on the sea surface, the salinity and temperature gradients, the local coastal morphology, the seabed bathymetry and the tide. The applied methodology is based on the Integrated Fluid Dynamic Simulation System HyperSuite developed by RSE. This simulation system includes the consideration of all the parameters previously listed, in the frame of a 3D Eulerian finite element fluid dynamic model, which accuracy is guaranteed by a very detailed spatial mesh and by an automatically optimized time step management. In order to assess the methodology features, an area of more than 2500 km2 and depth of 200 m located in the middle Adriatic Sea has been modelled. The information required for the simulation in

New test for oil soluble/water dispersible gas pipeline inhibitors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stegmann, D.W.; Asperger, R.G.

1987-01-01

The wheel test provides good mixing of the condensate and water phases, the coupons are exposed to both phases. Therefore, the wheel test cannot distinguish between inhibitors that need continuous mixing of the these phases to maintain a water dispersion of the inhibitor and inhibitors that will self disperse into the water. This concept becomes important for pipelines in stratified flow where the water can settle out. In these cases with low turbulence, the inhibitor must self disperse into the water to be effective. The paper describes a test method to measure the effectiveness of an inhibitor and its abilitymore » to self disperse. The effectiveness of several inhibitors as predicted by the new test method is discussed relative to data from the wheel test and breaker tests. Field performance of these inhibitors in a gas gathering line, with liquids in stratified flow, are cities and compared with the results of the various laboratory tests.« less

Determination of wear metals in engine oil by mild acid digestion and energy dispersive X-ray fluorescence spectrometry using solid phase extraction disks.

PubMed

Yang, Zheng; Hou, Xiandeng; Jones, Bradley T

2003-03-10

A simple, particle size-independent spectrometric method has been developed for the multi-element determination of wear metals in used engine oil. A small aliquot (0.5 ml) of an acid-digested oil sample is spotted onto a C-18 solid phase extraction disk to form a uniform thin film. The dried disk is then analyzed directly by energy dispersive X-ray fluorescence spectrometry. This technique provides a homogeneous and reproducible sample surface to the instrument, thus overcoming the typical problems associated with uneven particle size distribution and sedimentation. As a result, the method provides higher precision and accuracy than conventional methods. Furthermore, the disk sample may be stored and re-analyzed or extracted at a later date. The signals arising from the spotted disks, and the calibration curves constructed from them, are stable for at least 2 months. The limits of detection for Fe, Cu, Zn, Pb, and Cr are 5, 1, 4, 2, and 4 microg g(-1), respectively. Recoveries of these elements from spiked oil samples range from 92 to 110%. The analysis of two standard reference materials and a used oil sample produced results comparable to those found by inductively coupled plasma atomic emission spectrometry.

SOVENT BASED ENHANCED OIL RECOVERY FOR IN-SITU UPGRADING OF HEAVY OIL SANDS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Munroe, Norman

With the depletion of conventional crude oil reserves in the world, heavy oil and bitumen resources have great potential to meet the future demand for petroleum products. However, oil recovery from heavy oil and bitumen reservoirs is much more difficult than that from conventional oil reservoirs. This is mainly because heavy oil or bitumen is partially or completely immobile under reservoir conditions due to its extremely high viscosity, which creates special production challenges. In order to overcome these challenges significant efforts were devoted by Applied Research Center (ARC) at Florida International University and The Center for Energy Economics (CEE) atmore » the University of Texas. A simplified model was developed to assess the density of the upgraded crude depending on the ratio of solvent mass to crude oil mass, temperature, pressure and the properties of the crude oil. The simplified model incorporated the interaction dynamics into a homogeneous, porous heavy oil reservoir to simulate the dispersion and concentration of injected CO2. The model also incorporated the characteristic of a highly varying CO2 density near the critical point. Since the major challenge in heavy oil recovery is its high viscosity, most researchers have focused their investigations on this parameter in the laboratory as well as in the field resulting in disparaging results. This was attributed to oil being a complex poly-disperse blend of light and heavy paraffins, aromatics, resins and asphaltenes, which have diverse behaviors at reservoir temperature and pressures. The situation is exacerbated by a dearth of experimental data on gas diffusion coefficients in heavy oils due to the tedious nature of diffusivity measurements. Ultimately, the viscosity and thus oil recovery is regulated by pressure and its effect on the diffusion coefficient and oil swelling factors. The generation of a new phase within the crude and the differences in mobility between the new crude matrix and

Can matrix solid phase dispersion (MSPD) be more simplified? Application of solventless MSPD sample preparation method for GC-MS and GC-FID analysis of plant essential oil components.

PubMed

Wianowska, Dorota; Dawidowicz, Andrzej L

2016-05-01

This paper proposes and shows the analytical capabilities of a new variant of matrix solid phase dispersion (MSPD) with the solventless blending step in the chromatographic analysis of plant volatiles. The obtained results prove that the use of a solvent is redundant as the sorption ability of the octadecyl brush is sufficient for quantitative retention of volatiles from 9 plants differing in their essential oil composition. The extraction efficiency of the proposed simplified MSPD method is equivalent to the efficiency of the commonly applied variant of MSPD with the organic dispersing liquid and pressurized liquid extraction, which is a much more complex, technically advanced and highly efficient technique of plant extraction. The equivalency of these methods is confirmed by the variance analysis. The proposed solventless MSPD method is precise, accurate, and reproducible. The recovery of essential oil components estimated by the MSPD method exceeds 98%, which is satisfactory for analytical purposes. Copyright © 2016 Elsevier B.V. All rights reserved.

Experimental investigation of gas hydrate formation, plugging and transportability in partially dispersed and water continuous systems

NASA Astrophysics Data System (ADS)

Vijayamohan, Prithvi

As oil/gas subsea fields mature, the amount of water produced increases significantly due to the production methods employed to enhance the recovery of oil. This is true especially in the case of oil reservoirs. This increase in the water hold up increases the risk of hydrate plug formation in the pipelines, thereby resulting in higher inhibition cost strategies. A major industry concern is to reduce the severe safety risks associated with hydrate plug formation, and significantly extending subsea tieback distances by providing a cost effective flow assurance management/safety tool for mature fields. Developing fundamental understanding of the key mechanistic steps towards hydrate plug formation for different multiphase flow conditions is a key challenge to the flow assurance community. Such understanding can ultimately provide new insight and hydrate management guidelines to diminish the safety risks due to hydrate formation and accumulation in deepwater flowlines and facilities. The transportability of hydrates in pipelines is a function of the operating parameters, such as temperature, pressure, fluid mixture velocity, liquid loading, and fluid system characteristics. Specifically, the hydrate formation rate and plugging onset characteristics can be significantly different for water continuous, oil continuous, and partially dispersed systems. The latter is defined as a system containing oil/gas/water, where the water is present both as a free phase and partially dispersed in the oil phase (i.e., entrained water in the oil). Since hydrate formation from oil dispersed in water systems and partially dispersed water systems is an area which is poorly understood, this thesis aims to address some key questions in these systems. Selected experiments have been performed at the University of Tulsa flowloop to study the hydrate formation and plugging characteristics for the partially dispersed water/oil/gas systems as well as systems where the oil is completely dispersed

Heme Oxygenase-1 Protects Corexit 9500A-Induced Respiratory Epithelial Injury across Species

PubMed Central

Oliva, Octavio M.; Karki, Suman; Surolia, Ranu; Wang, Zheng; Watson, R. Douglas; Thannickal, Victor J.; Powell, Mickie; Watts, Stephen; Kulkarni, Tejaswini; Batra, Hitesh; Bolisetty, Subhashini; Agarwal, Anupam; Antony, Veena B.

2015-01-01

The effects of Corexit 9500A (CE) on respiratory epithelial surfaces of terrestrial mammals and marine animals are largely unknown. This study investigated the role of CE-induced heme oxygenase-1 (HO-1), a cytoprotective enzyme with anti-apoptotic and antioxidant activity, in human bronchial airway epithelium and the gills of exposed aquatic animals. We evaluated CE-mediated alterations in human airway epithelial cells, mice lungs and gills from zebrafish and blue crabs. Our results demonstrated that CE induced an increase in gill epithelial edema and human epithelial monolayer permeability, suggesting an acute injury caused by CE exposure. CE induced the expression of HO-1 as well as C-reactive protein (CRP) and NADPH oxidase 4 (NOX4), which are associated with ROS production. Importantly, CE induced caspase-3 activation and subsequent apoptosis of epithelial cells. The expression of the intercellular junctional proteins, such as tight junction proteins occludin, zonula occludens (ZO-1), ZO-2 and adherens junctional proteins E-cadherin and Focal Adhesion Kinase (FAK), were remarkably inhibited by CE, suggesting that these proteins are involved in CE-induced increased permeability and subsequent apoptosis. The cytoskeletal protein F-actin was also disrupted by CE. Treatment with carbon monoxide releasing molecule-2 (CORM-2) significantly inhibited CE-induced ROS production, while the addition of HO-1 inhibitor, significantly increased CE-induced ROS production and apoptosis, suggesting a protective role of HO-1 or its reaction product, CO, in CE-induced apoptosis. Using HO-1 knockout mice, we further demonstrated that HO-1 protected against CE-induced inflammation and cellular apoptosis and corrected CE-mediated inhibition of E-cadherin and FAK. These observations suggest that CE activates CRP and NOX4-mediated ROS production, alters permeability by inhibition of junctional proteins, and leads to caspase-3 dependent apoptosis of epithelial cells, while HO-1 and its

Dispersive micro solid phase extraction (DMSPE) using polymer anion exchange (PAX) as the sorbent followed by UPLC-MS/MS for the rapid determination of four bisphenols in commercial edible oils.

PubMed

Xian, Yanping; Wu, Yuluan; Dong, Hao; Guo, Xindong; Wang, Bin; Wang, Li

2017-09-29

The present work presents a novel and rapid analytical method for the simultaneous analysis of bisphenol A (BPA), bisphenol B (BPB), bisphenol F (BPF) and bisphenol S (BPS) in edible oil based on dispersive micro solid phase extraction (DMSPE) for the first time followed by isotope dilution-ultra high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). The edible oil sample was dispersed by n-hexane and extracted with ammoniated methanol-water solution. Then the target analytes were dispersedly absorbed using the polymer anion exchange (PAX) as the sorbent and eluted by acidic methanol. After that, four bisphenols were separated on a C18 column by gradient elution with methanol and 0.05% ammonium hydroxide in water as mobile phase, detected by MS/MS under multiple reactions monitoring (MRM) mode and quantified by internal standard method. The PAX amounts, adsorption time, concentrations of formic acid in the elution solvent and volume of elution solvent for the DMSPE technique were optimized. The limit of detection and quantitation (LOD and LOQ), matrix effect, recovery and precision of the developed method were investigated. Results indicated that BPS and the rest three bisphenols displayed excellent linearity in the concentration ranges of 0.1-50μg/L and 0.5-250μg/L, respectively, with correlation coefficients (R 2 ) all larger than 0.998. Achieved MLODs (S/N=3) varied between 0.1-0.4μg/kg for all bisphenols. The mean recoveries at three spiked levels in edible oil were in the range of 87.3-108%. Intra-day precision (n=6) and inter-day precision (n=5) were <9% and <11%, respectively. This method is of rapid-and-simple pretreatment, accurate and sensitive, and suitable for the simultaneous determination of bisphenols in edible oil. Copyright © 2017. Published by Elsevier B.V.

Ecological impacts of the Deepwater Horizon oil spill: implications for immunotoxicity

EPA Science Inventory

Summary of major Federal and multi-stake holder research efforts in response to the DWH spill, including laboratory oil dispersant testing, estimation of oil release rates and oil fate calculations, subsea monitoring, and post-spill assessments. Impacts from shoreline oiling, wil...

Effect of residual oil saturation on hydrodynamic properties of porous media

NASA Astrophysics Data System (ADS)

Zhang, Junjie; Zheng, Xilai; Chen, Lei; Sun, Yunwei

2014-07-01

To understand the effect of residual oil on hydraulic properties and solute dispersive behavior of porous media, miscible displacement column experiments were conducted using two petroleum products (diesel and engine oil) and a sandy soil. The effective water permeability, effective water-filled porosity, and dispersivity were investigated in two-fluid systems of water and oil as a function of residual oil saturation (ROS). At the end of each experiment, the distribution of ending ROS along the sand column was determined by the method of petroleum ether extraction-ultraviolet spectrophotometry. Darcy’s Law was used to determine permeability, while breakthrough curves (BTCs) of a tracer, Cl-, were used to calibrate effective porosity and dispersivity. The experimental results indicate that the maximum saturated zone residual saturation of diesel and engine oil in this study are 16.0% and 45.7%, respectively. Cl- is found to have no sorption on the solid matrix. Generated BTCs are sigmoid in shape with no evidence of tailing. The effective porosity of sand is inversely proportional to ROS. For the same level of ROS, the magnitude of reduction in effective porosity by diesel is close to that by engine oil. The relative permeability of sand to water saturation decreases with increasing amount of trapped oil, and the slope of the relative permeability-saturation curve for water is larger at higher water saturations, indicating that oil first occupies larger pores, which have the most contribution to the conductivity of the water. In addition, the reduction rate of relative permeability by diesel is greater than that by engine oil. The dispersivity increases with increasing ROS, suggesting that the blockage of pore spaces by immobile oil globules may enhance local velocity variations and increase the tortuosity of aqueous-phase flow paths.

Effects of Surface-Engineered Nanoparticle-Based Dispersants for Marine Oil Spills on the Model Organism Artemia franciscana

PubMed Central

2015-01-01

Fine particles are under active consideration as alternatives to chemical dispersants for large-scale petroleum spills. Fine carbon particles with engineered surface chemistry have been shown to stabilize oil-in-water emulsions, but the environmental impacts of large-scale particle introduction to the marine environment are unknown. Here we study the impact of surface-engineered carbon-black materials on brine shrimp (Artemia franciscana) as a model marine microcrustacean. Mortality was characterized at 50–1000 mg/L, and levels of heat shock protein 70 (hsp70) were characterized at sublethal particle concentrations (25–50 mg/L). Functionalized carbon black (CB) nanoparticles were found to be nontoxic at all concentrations, while hydrophobic (annealed) and as-produced CB induced adverse effects at high concentrations. CB was also shown to adsorb benzene, a model hydrocarbon representing the more soluble and toxic low-molecular weight aromatic fraction of petroleum, but the extent of adsorption was insufficient to mitigate benzene toxicity to Artemia in coexposure experiments. At lower benzene concentrations (25–75 mg/L), coexposure with annealed and as-produced CB increased hsp70 protein levels. This study suggests that surface functionalization for increased hydrophilicity can not only improve the performance of CB-based dispersants but also reduce their adverse environmental impacts on marine organisms. PMID:24823274

Photochemical Production of Aldehydes and Ketones from Petroleum Films on Seawater

NASA Astrophysics Data System (ADS)

Tarr, M. A.; Rebet, K.; Monin, L.; Bastian, G.

2016-02-01

While numerous reports have demonstrated that sunlight results in oxygenation of petroleum in environmental systems, few details are available regarding the specific mechanisms of these reactions. Previous studies have not been able to identify specific chemicals formed when oil is subjected to photochemical transformation. In this study, we have utilized several petroleum samples to investigate the formation of aldehyde and ketone photoproducts. These samples included oil from the MC252 well (source of the Deepwater Horizon spill), surrogate oil provided by BP to represent the MC252 oil, and residual fuel oil (NIST 2717a). Thin films of oil ( 100 μm) were placed over water and irradiated with a solar simulator for the equivalent of 1.5-12 days. After irradiation, the water was carefully separated from the oil and derivatized with 2,4-dinitrophenylhydrazine, a selective derivatization agent for aldehydes and ketones. The derivatized material was then analyzed by HPLC. Additional analysis by electrospray MS was also performed, and absorbance and fluorescence spectra of the underivatized aqueous phase were recorded. For all oils, exposure to sunlight resulted in release of aldehydes and ketones to the aqueous phase. The amount of released photoproducts was proportional to the length of solar exposure, but no production was seen for dark controls. Despite some similarities, the pattern of product formation varied from oil to oil. Addition of dispersant (Corexit 9500a or 9527a) resulted in larger amounts of aldehydes and ketones detected in the aqueous phase after solar irradiation of the oil. Electrospray mass spectrometry was utilized in an attempt to provide structural information about the aldehydes and ketones formed. Results of this study demonstrate that aldehydes and ketones are important photoproducts resulting from solar irradiation of oil on water. These products will affect the transport and bioavailability of oil spilled in aquatic systems.

Deep-sea oil plume enriches psychrophilic oil-degrading bacteria

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hazen, T.C.; Dubinsky, E.A.; DeSantis, T.Z.

The biological effects and expected fate of the vast amount of oil in the Gulf of Mexico from the Deepwater Horizon blowout are unknown owing to the depth and magnitude of this event. Here, we report that the dispersed hydrocarbon plume stimulated deep-sea indigenous {gamma}-Proteobacteria that are closely related to known petroleum degraders. Hydrocarbon-degrading genes coincided with the concentration of various oil contaminants. Changes in hydrocarbon composition with distance from the source and incubation experiments with environmental isolates demonstrated faster-than-expected hydrocarbon biodegradation rates at 5 C. Based on these results, the potential exists for intrinsic bioremediation of the oil plumemore » in the deep-water column without substantial oxygen drawdown.« less

Improving environmental assessments by integrating Species Sensitivity Distributions into environmental modeling: examples with two hypothetical oil spills.

PubMed

Bejarano, Adriana C; Mearns, Alan J

2015-04-15

A three dimensional (3D) trajectory model was used to simulate oil mass balance and environmental concentrations of two 795,000 L hypothetical oil spills modeled under physical and chemical dispersion scenarios. Species Sensitivity Distributions (SSD) for Total Hydrocarbon Concentrations (THCs) were developed, and Hazard Concentrations (HC) used as levels of concern. Potential consequences to entrained water column organisms were characterized by comparing model outputs with SSDs, and obtaining the proportion of species affected (PSA) and areas with oil concentrations exceeding HC5s (Area ⩾ HC5). Under the physically-dispersed oil scenario ⩽ 77% of the oil remains on the water surface and strands on shorelines, while with the chemically-dispersed oil scenario ⩽ 67% of the oil is entrained in the water column. For every 10% increase in chemical dispersion effectiveness, the average PSA and Area ⩾ HC5 increases (range: 0.01-0.06 and 0.50-2.9 km(2), respectively), while shoreline oiling decreases (⩽ 2919 L/km). Integrating SSDs into modeling may improve understanding of scales of potential impacts to water column organisms, while providing net environmental benefit comparison of oil spill response options. Copyright © 2015 Elsevier Ltd. All rights reserved.

A Microscopic View of Oil Slick Break-Up and Emulsion Formation in Breaking Waves

NASA Astrophysics Data System (ADS)

Law, J.; Shahrokhi, H.; Shaw, J. M.

1996-11-01

The hydrodynamic behaviour of oil spills in breaking waves determines the appropriateness and effectiveness of remedial measures during clean-up operations. Oil slicks either disperse as fine drops or form water in oil emulsions when exposed to breaking waves. However, there is little agreement with respect to the controlling variables or mechanisms for emulsification or dispersion and predictions are unreliable. For example, predicted energy dissipation rates in breaking waves are too low to account for the drop sizes encountered experimentally[1]. In this paper, we assess the impact of hydrodynamics and physical properties on the formation of dispersions or emulsions. The maximum stable drop size for dispersions arising from oil slicks and water in oil emulsions are shown to be controlled by Raleigh-Taylor instability or the prevalent local shear stress. Data from four experimental studies[2-5], with a broad range of physical properties were fitted quantitatively. As high shear events are intermittent, stable water in oil emulsions can be formed by dispersion inversion near the water air interface or by water entrained by gas bubbles passing through oil slicks. 1) Li & Garrett, 19th AMOP, Calgary AB, 1, 185-198 (1996). 2) Lin et al., Report CG-D-54-78, U.S. Coast Guard, Washington D.C. (1978). 3) Buist, MASc Thesis, University of Toronto (1979). 4) Wallace et al., 9th AMOP, Edmonton AB, 2, 421-429, June 10-12 (1986). 5) Ross Environmental Research Ltd., Ottawa ON, Report EE-96, (1987).

Detection of Oil in Water Column: Sensor Design

DTIC Science & Technology

2013-02-01

rivers , and initiating dispersant application or oil recovery operations. Challenges in detecting oil within the water column include poor...facility and along transects in the Delaware River . However, all readings were at background, even when there was visible oil on the water surface...levels for extremely high CDOM rich rivers . Detection of Oil in Water Column: Sensor Design 14 UNCLAS//Public | CG-926 RDC | Fitzpatrick, et al

Settling of dilbit-derived oil-mineral aggregates (OMAs) & transport parameters for oil spill modelling.

PubMed

O'Laughlin, Casey M; Law, Brent A; Zions, Vanessa S; King, Thomas L; Robinson, Brian; Wu, Yongsheng

2017-11-15

The size and settling velocity of oil-mineral aggregates (OMAs) derived from diluted bitumen are primary constituents in predictive models for evaluating the potential fate of oil spilled in the aquatic environment. A series of low sediment concentration (15mg·L -1 ), colder water (<10°C) wave tank experiments designed to measure variability in these parameters in naturally-formed OMAs in response the presence or absence of chemical dispersant are discussed. Corresponding lab experiments revealed settling velocities of artificially formed OMAs on the order of 0.1-0.4mm·s -1 . High-resolution imagery of settling particles were analyzed for particle size, density and settling velocity. In situ formation of OMAs in the wave tank was unsuccessful. Possible effects of chemical dispersant on natural sediment flocculation, the size of suspended oil droplets and clearance rates of suspended particles are discussed. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Detergent-dispersant additives based on high-molecular-weight alkylphenols

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kulieva, K.N.; Namazova, I.I.; Ismailova, N.D.

1988-09-01

This article describes the synthesis and investigation of Mannich bases produced for alkylphenols, obtained in turn from ethylene oligomers. These oligomers are the still bottoms from distillation products of high-temperature oligomerization of ethylene in the presence of triethylaluminum. Two narrow cuts obtained from the distillation of oligomer fraction were used to study the influence of ethylene oligomer molecular weight on the properties of the additives. The additives were blended in DS-11 oil to evaluate their detergency-dispersancy and other properties. Comparison blends were made with succinimide additives based on the same ethylene oligomers. The Mannich bases give improvements in the oxidationmore » resistance, anticorrosion properties, and detergency-dispersancy of the DS-11 diesel oil.« less

Influence of propylene glycol on aqueous silica dispersions and particle-stabilized emulsions.

PubMed

Binks, Bernard P; Fletcher, Paul D I; Thompson, Michael A; Elliott, Russell P

2013-05-14

We have studied the influence of adding propylene glycol to both aqueous dispersions of fumed silica nanoparticles and emulsions of paraffin liquid and water stabilized by the same particles. In the absence of oil, aerating mixtures of aqueous propylene glycol and particles yields either stable dispersions, aqueous foams, climbing particle films, or liquid marbles depending on the glycol content and particle hydrophobicity. The presence of glycol in water promotes particles to behave as if they are more hydrophilic. Calculations of their contact angle at the air-aqueous propylene glycol surface are in agreement with these findings. In the presence of oil, particle-stabilized emulsions invert from water-in-oil to oil-in-water upon increasing either the inherent hydrophilicity of the particles or the glycol content in the aqueous phase. Stable multiple emulsions occur around phase inversion in systems of low glycol content, and completely stable, waterless oil-in-propylene glycol emulsions can also be prepared. Accounting for the surface energies at the respective interfaces allows estimation of the contact angle at the oil-polar phase interface; reasonable agreement between measured and calculated phase inversion conditions is found assuming no glycol adsorption on particle surfaces.

A Sugar-Based Gelator for Marine Oil-Spill Recovery.

PubMed

Vibhute, Amol M; Muvvala, Venkatanarayana; Sureshan, Kana M

2016-06-27

Marine oil spills constitute an environmental disaster with severe adverse effects on the economy and ecosystem. Phase-selective organogelators (PSOGs), molecules that can congeal oil selectively from oil-water mixtures, have been proposed to be useful for oil-spill recovery. However, a major drawback lies in the mode of application of the PSOG to an oil spill spread over a large area. The proposed method of using carrier solvents is impractical for various reasons. Direct application of the PSOG as a solid, although it would be ideal, is unknown, presumably owing to poor dispersion of the solid through the oil. We have designed five cheap and easy-to-make glucose-derived PSOGs that disperse in the oil phase uniformly when applied as a fine powder. These gelators were shown to selectively congeal many oils, including crude oil, from oil-water mixtures to form stable gels, which is an essential property for efficient oil-spill recovery. We have demonstrated that these PSOGs can be applied aerially as a solid powder onto a mixture of crude oil and sea water and the congealed oil can then be scooped out. Our innovative mode of application and low cost of the PSOG offers a practical solution to oil-spill recovery. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Functionalized Carbon Nanotubes in Modified Plant Oil Composites.

NASA Astrophysics Data System (ADS)

McAninch, Ian M.; Wool, Richard P.

2007-03-01

Carbon nanotubes (CNTs) with their impressive mechanical properties are ideal reinforcement material. Acrylated epoxidized soy oil (AESO) has been previously shown to have favorable interactions with carbon nanotubes; however a mixture of aggregates and dispersed tubes were found even at low CNT concentrations. In order to prevent re-aggregation, the CNTs were functionalized with a 10 carbon long aliphatic chain. These aliphatic chains are similar to the fatty acids that make up soy oil. Functionalization was verified using XPS and IR spectroscopy. These functionalized CNTs were dispersed by mechanical shear mixing into AESO both with and without styrene as a comonomer. No large aggregates were observed in the liquid, uncured, samples or in the final cured composites. Dispersion in the solid composites was verified using optical and electron microscopy. Better dispersion also resulted in improved mechanical properties.

Flotation mechanisms of molybdenite fines by neutral oils

NASA Astrophysics Data System (ADS)

Lin, Qing-quan; Gu, Guo-hua; Wang, Hui; Liu, You-cai; Fu, Jian-gang; Wang, Chong-qing

2018-01-01

The flotation mechanisms of molybdenite fines by neutral oils were investigated through microflotation test, turbidity measurements, infrared spectroscopy, and interfacial interaction calculations. The results of the flotation test show that at pH 2-11, the floatability of molybdenite fines in the presence of transformer oil is markedly better than that in the presence of kerosene and diesel oil. The addition of transformer oil, which enhances the floatability of molybdenite fines, promotes the aggregation of molybdenite particles. Fourier transform infrared measurements illustrate that physical interaction dominates the adsorption mechanism of neutral oil on molybdenite. Interfacial interaction calculations indicate that hydrophobic attraction is the crucial force that acts among the oil collector, water, and molybdenite. Strong hydrophobic attraction between the oily collector and water provides the strong dispersion capability of the collector in water. Furthermore, the dispersion capability of the collector, not the interaction strength between the oily collectors and molybdenite, has a highly significant role in the flotation system of molybdenite fines. Our findings provide insights into the mechanism of molybdenite flotation.

Flow behavior of N2 huff and puff process for enhanced oil recovery in tight oil reservoirs.

PubMed

Lu, Teng; Li, Zhaomin; Li, Jian; Hou, Dawei; Zhang, Dingyong

2017-11-16

In the present work, the potential of N 2 huff and puff process to enhance the recovery of tight oil reservoir was evaluated. N 2 huff and puff experiments were performed in micromodels and cores to investigate the flow behaviors of different cycles. The results showed that, in the first cycle, N 2 was dispersed in the oil, forming the foamy oil flow. In the second cycle, the dispersed gas bubbles gradually coalesced into the continuous gas phase. In the third cycle, N 2 was produced in the form of continuous gas phase. The results from the coreflood tests showed that, the primary recovery was only 5.32%, while the recoveries for the three N 2 huff and puff cycles were 15.1%, 8.53% and 3.22%, respectively.The recovery and the pressure gradient in the first cycle were high. With the increase of huff and puff cycles, and the oil recovery and the pressure gradient rapidly decreased. The oil recovery of N 2 huff and puff has been found to increase as the N 2 injection pressure and the soaking time increased. These results showed that, the properly designed and controlled N 2 huff and puff process can lead to enhanced recovery of tight oil reservoirs.

The deepwater horizon oil spill coast guard cohort study: A cross-sectional study of acute respiratory health symptoms.

PubMed

Alexander, Melannie; Engel, Lawrence S; Olaiya, Nathan; Wang, Li; Barrett, John; Weems, Laura; Schwartz, Erica G; Rusiecki, Jennifer A

2018-04-01

Over 8500 United States Coast Guard (USCG) personnel were deployed in response to the Deepwater Horizon (DWH) oil spill; however, human respiratory effects as a result of spill-related exposures are relatively unknown. USCG personnel who responded to the DWH oil spill were queried via survey on exposures to crude oil and oil dispersant, and acute respiratory symptoms experienced during deployment. Adjusted log binomial regressions were used to calculate prevalence ratios (PRs) and 95% confidence intervals (CI), investigating the associations between oil spill exposures and respiratory symptoms. 4855 USCG personnel completed the survey. More than half (54.6%) and almost one-fourth (22.0%) of responders were exposed to crude oil and oil dispersants, respectively. Coughing was the most prevalent symptom (19.4%), followed by shortness of breath (5.5%), and wheezing (3.6%). Adjusted analyses showed an exposure-response relationship between increasing deployment duration and likelihood of coughing, shortness of breath, and wheezing in the pre-capping period. A similar pattern was observed in the post-capping period for coughing and wheezing. Adjusted analyses revealed increased PRs for coughing (PR=1.92), shortness of breath (PR=2.60), and wheezing (PR=2.68) for any oil exposure. Increasing frequency of inhalation of oil was associated with increased likelihood of all three respiratory symptoms. A similar pattern was observed for contact with oil dispersants for coughing and shortness of breath. The combination of both oil and oil dispersants presented associations that were much greater in magnitude than oil alone for coughing (PR=2.72), shortness of breath (PR=4.65), and wheezing (PR=5.06). Results from the present study suggested strong relationships between oil and oil dispersant exposures and acute respiratory symptoms among disaster responders. Future prospective studies will be needed to confirm these findings. Copyright © 2017 Elsevier Inc. All rights reserved.

Development of oil product toxicity benchmarks using SSDs

EPA Science Inventory

Determining the sensitivity of a diversity of species to spilled oil and chemically dispersed oil continues to be a significant challenge in spill response and impact assessment. We developed species sensitivity distributions (SSDs) of acute toxicity values using standardized te...

Development of alginate microspheres containing thyme essential oil using ionic gelation.

PubMed

Benavides, Sergio; Cortés, Pablo; Parada, Javier; Franco, Wendy

2016-08-01

Essential oils are a good antimicrobial and antioxidant agent alternative in human or animal feed. However, their direct use has several disadvantages such as volatilization or oxidation. The development of essential oil microspheres may help to avoid these problems. The objective of the present research was to microencapsulate thyme essential oil by generating emulsions with different dispersion degrees. The emulsions were encapsulated in calcium-alginate microspheres by ionic gelation. The microspheres were evaluated regarding size, shape, encapsulation efficiency, loading capacity and antimicrobial properties. The results indicate that encapsulation efficiency and loading capacity are dependent on concentration and degree of dispersion. The best encapsulation conditions were obtained at 2% v/v of thyme essential oil with a high dispersion degree (18,000rpm/5min), which was achieved with an efficiency of 85%. Finally, the microspheres obtained showed significant antimicrobial effect, especially in gram-positive bacteria. Copyright © 2016 Elsevier Ltd. All rights reserved.

Simultaneous determination of six synthetic phenolic antioxidants in edible oils using dispersive liquid-liquid microextraction followed by high-performance liquid chromatography with diode array detection.

PubMed

Xu, Shuangjiao; Liu, Liangliang; Wang, Yanqin; Zhou, Dayun; Kuang, Meng; Fang, Dan; Yang, Weihua; Wei, Shoujun; Xiao, Aiping; Ma, Lei

2016-08-01

A simple, rapid, organic-solvent- and sample-saving pretreatment technique, called dispersive liquid-liquid microextraction, was developed for the determination of six synthetic phenolic antioxidants from edible oils before high-performance liquid chromatography with diode array detection. The entire procedure was composed of a two-step microextraction and a centrifugal process and could be finished in about 5 min, only consuming only 25 mg of sample and 1 mL of the organic solvent for each extraction. The influences of several important parameters on the microextraction efficiency were thoroughly investigated. Recovery assays for oil samples were spiked at three concentration levels, 50, 100 and 200 mg/kg, and provided recoveries in the 86.3-102.5% range with a relative standard deviation below 3.5%. The intra-day and inter-day precisions for the analysis were less than 3.8%. The proposed method was successfully applied for the determination of synthetic phenolic antioxidants in different oil samples, and satisfactory results were obtained. Thus, the developed method represents a viable alternative for the quality control of synthetic phenolic antioxidant concentrations in edible oils. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Simultaneous Determination of Perfluorinated Compounds in Edible Oil by Gel-Permeation Chromatography Combined with Dispersive Solid-Phase Extraction and Liquid Chromatography-Tandem Mass Spectrometry.

PubMed

Yang, Lili; Jin, Fen; Zhang, Peng; Zhang, Yanxin; Wang, Jian; Shao, Hua; Jin, Maojun; Wang, Shanshan; Zheng, Lufei; Wang, Jing

2015-09-30

A simple analytical method was developed for the simultaneous analysis of 18 perfluorinated compounds (PFCs) in edible oil. The target compounds were extracted by acetonitrile, purified by gel permeation chromatography (GPC) and dispersive solid-phase extraction (DSPE) using graphitized carbon black (GCB) and octadecyl (C18), and analyzed by liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ES-MS/MS) in negative ion mode. Recovery studies were performed at three fortification levels. The average recoveries of all target PFCs ranged from 60 to 129%, with an acceptable relative standard deviation (RSD) (1-20%, n = 3). The method detection limits (MDLs) ranged from 0.004 to 0.4 μg/kg, which was significantly improved compared with the existing liquid-liquid extraction and cleanup method. The method was successfully applied for the analysis of all target PFCs in edible oil samples collected from markets in Beijing, China, and the results revealed that C6-C10 perfluorocarboxylic acid (PFCAs) and C7 perfluorosulfonic acid PFSAs were the major PFCs detected in oil samples.

Novel insight into the role of heterotrophic dinoflagellates in the fate of crude oil in the sea.

PubMed

Almeda, Rodrigo; Connelly, Tara L; Buskey, Edward J

2014-12-19

Although planktonic protozoans are likely to interact with dispersed crude oil after a spill, protozoan-mediated processes affecting crude oil pollution in the sea are still not well known. Here, we present the first evidence of ingestion and defecation of physically or chemically dispersed crude oil droplets (1-86 μm in diameter) by heterotrophic dinoflagellates, major components of marine planktonic food webs. At a crude oil concentration commonly found after an oil spill (1 μL L(-1)), the heterotrophic dinoflagellates Noctiluca scintillans and Gyrodinium spirale grew and ingested ~0.37 μg-oil μg-C(dino)(-1) d(-1), which could represent ~17% to 100% of dispersed oil in surface waters when heterotrophic dinoflagellates are abundant or bloom. Egestion of faecal pellets containing crude oil by heterotrophic dinoflagellates could contribute to the sinking and flux of toxic petroleum hydrocarbons in coastal waters. Our study indicates that crude oil ingestion by heterotrophic dinoflagellates is a noteworthy route by which petroleum enters marine food webs and a previously overlooked biological process influencing the fate of crude oil in the sea after spills.

Photoenhanced toxicity of oil to larval fish - abstract

EPA Science Inventory

Photoenhanced toxicity is the increase in the toxicity of a chemical in the presence of ultraviolet light (UV), compared to toxicity elicited under conditions of minimal UV. A variety of oil products, weathered and chemically dispersed oils, and specific polycyclic aromatic compo...

Development and Practical Application of Petroleum and Dispersant Interspecies Correlation Models for Aquatic Species

EPA Science Inventory

Assessing the acute toxicity of physically and chemically dispersed oil following an oil spill has generally relied on existing toxicological data for a relatively limited number of aquatic species. Recognition of differences in species sensitivities to contaminants has facilitat...

The biodegradation of crude oil in the deep ocean.

PubMed

Prince, Roger C; Nash, Gordon W; Hill, Stephen J

2016-10-15

Oil biodegradation at a simulated depth of 1500m was studied in a high-pressure apparatus at 5°C, using natural seawater with its indigenous microbes, and 3ppm of an oil with dispersant added at a dispersant:oil ratio of 1:15. Biodegradation of the detectable hydrocarbons was prompt and extensive (>70% in 35days), although slower by about a third than under otherwise identical conditions equivalent to the surface. The apparent half-life of biodegradation of the total detectable hydrocarbons at 15MPa was 16days (compared to 13days at atmospheric pressure), although some compounds, such as the four-ring aromatic chrysene, were degraded rather more slowly. Copyright © 2016 Elsevier Ltd. All rights reserved.

Mathematical modelling of oil spill fate and transport in the marine environment incorporating biodegradation kinetics of oil droplets

NASA Astrophysics Data System (ADS)

Spanoudaki, Katerina

2016-04-01

Oil biodegradation by native bacteria is one of the most important natural processes that can attenuate the environmental impacts of marine oil spills. However, very few numerical models of oil spill fate and transport include biodegradation kinetics of spilled oil. Furthermore, in models where biodegradation is included amongst the oil transformation processes simulated, it is mostly represented as a first order decay process neglecting the effect of several important parameters that can limit biodegradation rate, such as oil composition and oil droplets-water interface. To this end, the open source numerical model MEDSKIL-II, which simulates oil spill fate and transport in the marine environment, has been modified to include biodegradation kinetics of oil droplets dispersed in the water column. MEDSLIK-II predicts the transport and weathering of oil spills following a Lagrangian approach for the solution of the advection-diffusion equation. Transport is governed by the 3D sea currents and wave field provided by ocean circulation models. In addition to advective and diffusive displacements, the model simulates several physical and chemical processes that transform the oil (evaporation, emulsification, dispersion in the water column, adhesion to coast). The fate algorithms employed in MEDSLIK-II consider the oil as a uniform substance whose properties change as the slick weathers, an approach that can lead to reduced accuracy, especially in the estimation of oil evaporation and biodegradation. Therefore MEDSLIK-II has been modified by adopting the "pseudo-component" approach for simulating weathering processes. Spilled oil is modelled as a relatively small number of discrete, non-interacting components (pseudo-components). Chemicals in the oil mixture are grouped by physical-chemical properties and the resulting pseudo-component behaves as if it were a single substance with characteristics typical of the chemical group. The fate (evaporation, dispersion

Assessing weathered Endicott oil biodegradation in brackish water.

PubMed

Personna, Yves Robert; King, Thomas; Boufadel, Michel C; Zhang, Shuangyi; Kustka, Adam

2014-09-15

We evaluated the biodegradability of physically (WAF) and chemically (CEWAF) dispersed oil in brackish water (salinity ∼6.5 g/L), and the influence of nutrient availability (low nutrient-LN: background water vs. high nutrient-HN: addition of 100 mg NO3-N/L and 10mg PO4-P/L to background water) on oil biodegradation rates at 15±0.5 °C for 42 days. No oil removal occurred in WAF compared with CEWAF: 24% in HN and 14% in LN within two weeks. The oil biodegradation concerned mainly alkanes as confirmed by GC/MS analyses. Higher O2 consumption (10.30 mg L(-1) day(-1)) and CO2 production (3.89 mg CL(-1) day(-1)) were measured in HN compared with LN (O2: 2.79 mg L(-1) day(-1), CO2:0.18 mg CL(-1) day(-1)). Estimated biomass of hydrocarbon degraders and heterotrophic bacteria was at least an order of magnitude larger in HN than in LN. Combining dispersants with nutrients could enhance oil biodegradation and help improve oil spill mitigation responses. Copyright © 2014 Elsevier Ltd. All rights reserved.

30 CFR 254.27 - What information must I include in the “Dispersant use plan” appendix?

Code of Federal Regulations, 2014 CFR

2014-07-01

... ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL-SPILL RESPONSE REQUIREMENTS FOR FACILITIES LOCATED SEAWARD OF THE COAST LINE Oil-Spill Response Plans for Outer Continental Shelf Facilities § 254.27 What... location of the dispersants and other chemical or biological products which you might use on the oils...

30 CFR 254.27 - What information must I include in the “Dispersant use plan” appendix?

Code of Federal Regulations, 2013 CFR

2013-07-01

... ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL-SPILL RESPONSE REQUIREMENTS FOR FACILITIES LOCATED SEAWARD OF THE COAST LINE Oil-Spill Response Plans for Outer Continental Shelf Facilities § 254.27 What... location of the dispersants and other chemical or biological products which you might use on the oils...

30 CFR 254.27 - What information must I include in the “Dispersant use plan” appendix?

Code of Federal Regulations, 2010 CFR

2010-07-01

..., DEPARTMENT OF THE INTERIOR OFFSHORE OIL-SPILL RESPONSE REQUIREMENTS FOR FACILITIES LOCATED SEAWARD OF THE COAST LINE Oil-Spill Response Plans for Outer Continental Shelf Facilities § 254.27 What information... of the dispersants and other chemical or biological products which you might use on the oils handled...

30 CFR 254.27 - What information must I include in the “Dispersant use plan” appendix?

Code of Federal Regulations, 2012 CFR

2012-07-01

... ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL-SPILL RESPONSE REQUIREMENTS FOR FACILITIES LOCATED SEAWARD OF THE COAST LINE Oil-Spill Response Plans for Outer Continental Shelf Facilities § 254.27 What... location of the dispersants and other chemical or biological products which you might use on the oils...

An Experiment on the Dispersion of Light

ERIC Educational Resources Information Center

Thompson, Frank

2012-01-01

A simplified theoretical explanation of dispersion in dielectric materials has been given and experiments have been carried out on two liquids, namely, distilled water and sunflower oil. The appendix contains a detailed description of the construction of a homemade spectrometer and hollow prism and an assessment of its suitability for the above…

Novel insight into the role of heterotrophic dinoflagellates in the fate of crude oil in the sea

PubMed Central

Almeda, Rodrigo; Connelly, Tara L.; Buskey, Edward J.

2014-01-01

Although planktonic protozoans are likely to interact with dispersed crude oil after a spill, protozoan-mediated processes affecting crude oil pollution in the sea are still not well known. Here, we present the first evidence of ingestion and defecation of physically or chemically dispersed crude oil droplets (1–86 μm in diameter) by heterotrophic dinoflagellates, major components of marine planktonic food webs. At a crude oil concentration commonly found after an oil spill (1 μL L−1), the heterotrophic dinoflagellates Noctiluca scintillans and Gyrodinium spirale grew and ingested ~0.37 μg-oil μg-Cdino−1 d−1, which could represent ~17% to 100% of dispersed oil in surface waters when heterotrophic dinoflagellates are abundant or bloom. Egestion of faecal pellets containing crude oil by heterotrophic dinoflagellates could contribute to the sinking and flux of toxic petroleum hydrocarbons in coastal waters. Our study indicates that crude oil ingestion by heterotrophic dinoflagellates is a noteworthy route by which petroleum enters marine food webs and a previously overlooked biological process influencing the fate of crude oil in the sea after spills. PMID:25523528

Gelled oil particles: a new approach to encapsulate a hydrophobic metallophthalocyanine.

PubMed

Siqueira-Moura, Marigilson P; Franceschi-Messant, Sophie; Blanzat, Muriel; Ré, Maria Inês; Perez, Emile; Rico-Lattes, Isabelle; Lattes, Armand; Tedesco, Antonio C

2013-07-01

Chloroaluminum phthalocyanine (ClAlPc) is a promising sensitizer molecule for photodynamic therapy, but its hydrophobicity makes it difficult to formulate. In this study, we have efficiently encapsulated ClAlPc into gelled soybean oil particles dispersed in water. 12-Hydroxystearic acid (HSA) and polyethyleneimine (PEI) were the gelling and stabilizing agents, respectively. The preparation process involved hot emulsification above the gelation temperature (Tgel), followed by cooling to room temperature, which gave a colloidal dispersion of gelled particles of oil in aqueous medium. The gelled particles containing ClAlPc had a medium diameter of 280 nm, homogeneous size distribution (polydispersity index ≈0.3) and large positive zeta potential (about +50 mV) and showed a spherical morphology. The gelled oil particle formulations exhibited good physical stability over a 6-month period. ClAlPc interfered with the HSA self-assembly only slightly, and decreased the gelation temperature to a small extent; however it did not affect gelation process of the oil droplets. The amounts of PEI and HSA employed during the preparation allowed us to control particle size and the dispersion stability, a phenomenon that results from complex electrostatic interactions between the positively charged PEI and the negatively charged HSA fibers present on the gelled particles surface. In summary, by using the right ClAlPc, HSA, and PEI proportions, we prepared very stable dispersions of gelled soybean oil particles with excellent ClAlPc encapsulation efficiency. The obtained colloidal formulation of gelled oil particles loaded with ClAlPc shall be very useful for photodynamic therapy protocols. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

An improved dispersive solid-phase extraction clean-up method for the gas chromatography-negative chemical ionisation tandem mass spectrometric determination of multiclass pesticide residues in edible oils.

PubMed

Deme, Pragney; Azmeera, Tirupathi; Prabhavathi Devi, B L A; Jonnalagadda, Padmaja R; Prasad, R B N; Vijaya Sarathi, U V R

2014-01-01

An improved sample preparation using dispersive solid-phase extraction clean-up was proposed for the trace level determination of 35 multiclass pesticide residues (organochlorine, organophosphorus and synthetic pyrethroids) in edible oils. Quantification of the analytes was carried out by gas chromatography-mass spectrometry in negative chemical ionisation mode (GC-NCI-MS/MS). The limit of detection and limit of quantification of residues were in the range of 0.01-1ng/g and 0.05-2ng/g, respectively. The analytes showed recoveries between 62% and 110%, and the matrix effect was observed to be less than 25% for most of the pesticides. Crude edible oil samples showed endosulfan isomers, p,p'-DDD, α-cypermethrin, chlorpyrifos, and diazinon residues in the range of 0.56-2.14ng/g. However, no pesticide residues in the detection range of the method were observed in refined oils. Copyright © 2013 Elsevier Ltd. All rights reserved.

Anomalous dispersion due to hydrocarbons: The secret of reservoir geophysics?

USGS Publications Warehouse

Brown, R.L.

2009-01-01

When P- and S-waves travel through porous sandstone saturated with hydrocarbons, a bit of magic happens to make the velocities of these waves more frequency-dependent (dispersive) than when the formation is saturated with brine. This article explores the utility of the anomalous dispersion in finding more oil and gas, as well as giving a possible explanation about the effect of hydrocarbons upon the capillary forces in the formation. ?? 2009 Society of Exploration Geophysicists.

Ecological Impacts during the Deepwater Horizon Oil Spill

EPA Science Inventory

The Deepwater Horizon (DWH) oil spill was the largest spill and response effort in United States history. Nearly 800 million L of oil was spilled in the Gulf of Mexico, and nearly 7 million L of chemical dispersants were applied in at the ocean surface and subsea1. The DWH spill ...

The influence of agitation on oil substrate dispersion and oxygen transfer in Pseudomonas aeruginosa USM-AR2 fermentation producing rhamnolipid in a stirred tank bioreactor.

PubMed

Nur Asshifa, M N; Zambry, Nor Syafirah; Salwa, M S; Yahya, Ahmad R M

2017-07-01

Water-immiscible substrate, diesel, was supplied as the main substrate in the fermentation of Pseudomonas aeruginosa USM-AR2 producing rhamnolipid biosurfactant, in a stirred tank bioreactor. In addition to the typical gas-aqueous system, this system includes gas-hydrocarbon-aqueous phases and the presence of surfactant (rhamnolipid) in the fermentation broth. The effect of diesel dispersion on volumetric oxygen transfer coefficient, k L a, and thus oxygen transfer, was evaluated at different agitations of 400, 500 and 600 rpm. The oxygen transfer in this oil-water-surfactant system was shown to be affected by different oil dispersion at those agitation rates. The highest diesel dispersion was obtained at 500 rpm or impeller tip speed of 1.31 m/s, compared to 400 and 600 rpm, which led to the highest k L a, growth and rhamnolipid production by P. aeruginosa USM-AR2. This showed the highest substrate mixing and homogenization at this agitation speed that led to the efficient substrate utilization by the cells. The oxygen uptake rate of P. aeruginosa USM-AR2 was 5.55 mmol/L/h, which showed that even the lowest k L a (48.21 h -1 ) and hence OTR (57.71 mmol/L/h) obtained at 400 rpm was sufficient to fulfill the oxygen demand of the cells. The effect of rhamnolipid concentration on k L a showed that k L a increased as rhamnolipid concentration increased to 0.6 g/L before reaching a plateau. This trend was similar for all agitation rates of 400, 500 and 600 rpm, which might be due to the increase in the resistance to oxygen transfer (k L decrease) and the increase in the specific interfacial area (a).

Possibility of wax control techniques in Indonesian oil fields

NASA Astrophysics Data System (ADS)

Abdurrahman, M.; Ferizal, F. H.; Husna, U. Z.; Pangaribuan, L.

2018-03-01

Wax is one of the common problem which can reduce the oil production, especially for the reservoir with high paraffin content case. When the temperature of crude oil is lower than pour point, wax molecules can begin rapidly precipitated. The impacts of this problem are the clogging of production equipment, sealing off the pores in the reservoir, and decreasing production flow rate. In order to solve the wax problem, several methods have been applied in some oil fields in the world. For example, chemical methods in Jiangsu field (China) and Mumbai High field (India), hot water in Mangala field (India), magnetic method in Daqing field (China), water-dispersible in Bakken basin (US), and microbial in Jidong field (China). In general, the various crude oils present in the Indonesia contain wax content between 10%-39% and pour point of 22°C-49°C. Hot water and chemical method are commonly used to solve wax problems in Indonesian oil fields. However, the primary solution is magnetic method, and the secondary solution is water dispersible.

Low-VOC wood floor varnishes from waterborne oil-modified urethanes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ingle, D.M.; Petschke, G.H.

Varnishes protect wood flooring and enhance its beauty. Varnish compositions have varied from drying oils and alkyds to more durable systems (moisture-cured urethanes, oil-modified urethanes, epoxies and UV-curable coatings). Some chemistries are better suited for professional or factory applied situations. Oils, alkyds and oil-modified urethanes (OMU) are suitable for onsite professional application or even refinish application by homeowners (DIY market). These materials traditionally have been high in VOC. Recently, waterborne (WB) systems (such as polyurethane dispersions) with greatly reduced VOC have been used; high costs and relatively poor durability are drawbacks. A new generation of high performance waterborne oil-modified urethanemore » is now available with extended shelf-stability required for contractor and consumer markets. Formulated varnishes are coming onto the market that offer performance similar to conventional OMU, but with significant reductions in VOC. For example, a typical formulation for a conventional solvent-borne oil-modified urethane can be supplied at 1.6 lb/gal (less water). This represents a VOC reduction of 70-75% at equal application coating weight. Furthermore, waterborne oil-modified urethane offers advantages over polyurethane dispersions in performance areas such as durability and mar resistance.« less

Characteristics and oil sorption effectiveness of kapok fibre, sugarcane bagasse and rice husks: oil removal suitability matrix.

PubMed

Ali, Norizan; El-Harbawi, Mohanad; Jabal, Ayman Abo; Yin, Chun-Yang

2012-01-01

The characteristics and water/oil sorption effectiveness ofkapok fibre, sugarcane bagasse and rice husks have been compared. The three biomass types were subjected to field emission scanning electron microscopy-energy dispersive X-ray spectroscopy and surface tension analyses for liquid-air and oil-water systems were conducted. Both kapok fibre and sugarcane bagasse exhibit excellent oil sorption capabilities for diesel, crude, new engine and used engine oils as their oil sorption capacities all exceed 10 g/g. The synthetic sorbent exhibits oil sorption capacities comparable with sugarcane bagasse, while rice husks exhibit the lowest oil sorption capacities among all the sorbents. Kapok fibre shows overwhelmingly high oil-to-water sorption (O/W) ratios ranging from 19.35 to 201.53 while sugarcane bagasse, rice husks and synthetic sorbent have significantly lower O/W ratios (0.76-2.69). This suggests that kapok fibre is a highly effective oil sorbent even in well-mixed oil-water media. An oil sorbent suitability matrix is proposed to aid stakeholders in evaluating customized oil removal usage of the natural sorbents.

A green deep eutectic solvent dispersive liquid-liquid micro-extraction (DES-DLLME) for the UHPLC-PDA determination of oxyprenylated phenylpropanoids in olive, soy, peanuts, corn, and sunflower oil.

PubMed

Ferrone, Vincenzo; Genovese, Salvatore; Carlucci, Maura; Tiecco, Matteo; Germani, Raimondo; Preziuso, Francesca; Epifano, Francesco; Carlucci, Giuseppe; Taddeo, Vito Alessandro

2018-04-15

A green dispersive liquid-liquid microextraction (DLLME) using deep eutectic solvent (DES) as the extracting solvent has been developed and applied for the simultaneous quantification of ferulic acid, umbelliferone, boropinic acid, 7-isopentenyloxycoumarin, 4'-geranyloxyferulic acid (GOFA), and auraptene in some vegetable oils using ultra high performance liquid chromatography (UHPLC) with photodiode array detection (PDA). All parameters in the extraction step, including selection and loading of both extracting and dispersing solvents, amount of both extractant and disperser solvent were investigated and optimized. PhAA/TMG DES achieved higher recovery and enrichment factor compared to other DESs. The validated method showed good linearity with correlation coefficients, r 2 >0.9990 for all the analytes. Furthermore, this is the first time that eco-friendly solvents are used for the extraction of oxyprenylated phenylpropanoids and the corresponding extract analyzed with ultra high performance liquid chromatography with photodiode array detection. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Potential of Graphene as an Adsorbent for Five Pesticides from Different Classes in Rape Oil Samples Using Dispersive Solid-Phase Extraction.

PubMed

Madej, Katarzyna; Janiga, Katarzyna; Piekoszewski, Wojciech

2018-01-01

Isolation conditions for five pesticides (metazachlor, tebuconazole, λ -cyhalothrin, chlorpyrifos, and deltamethrin) from rape oil samples were examined using the dispersive solid-phase graphene extraction technique. To determine the optimal extraction conditions, a number of experimental factors (amount of graphene, amount of salt, type and volume of the desorbing solvent, desorption time with and without sonication energy, and temperature during desorption) were studied. The compounds of interest were separated and detected by an HPLC-UV employing a Kinetex XB-C18 column and a mobile phase consisting of acetonitrile and water flowing in a gradient mode. The optimized extraction conditions were: the amount of graphene 15 mg, desorbing solvent (acetonitrile) 5 mL, time desorption 10 min at 40°C, and amount of NaCl 1 g. The detection limit for metazachlor, tebuconazole, λ -cyhalothrin, and chlorpyrifos was 62.5 ng·g -1 , and for deltamethrin, it was 500 ng·g -1 . The obtained results lead to the conclusion that graphene may be successfully used for the isolation of the five pesticides from rape oil. However, their determination at low concentration levels, as they occur in real oil samples, requires the employment of appropriately highly sensitive analytical methods, as well as a more suitable graphene form (e.g., magnetically modified graphene).

Assessment Of Chemical Dispersant Effectiveness In A Wave Tank Under Regular Non-Breaking And Breaking Wave Conditions

EPA Science Inventory

Current chemical dispersant effectiveness tests for product selection are commonly performed with bench-scale testing apparatus. However, for the assessment of oil dispersant effectiveness under real sea state conditions, test protocols are required to have hydrodynamic conditio...

Interaction of oil and mineral fines on shorelines: review and assessment.

PubMed

Owens, Edward H; Lee, Kenneth

2003-01-01

The interaction of fine mineral particles with stranded oil in an aqueous medium reduces the adhesion of the oil to solid surfaces, such as sediments or bedrock. The net result is the formation of stable, micron-sized, oil droplets that disperse into the water column. In turn, the increase in surface area makes the oil more available for biodegradation. This interaction, referred to as oil-mineral aggregate (OMA) formation, can explain how oiled shorelines are cleaned naturally in the absence of wave action in very sheltered coastal environments. OMA formation also plays an important role in the efficacy of shoreline treatment techniques, such as physical mixing and sediment relocation that move oiled sediments into the zone of wave action to promote the interaction between oil and mineral fines. Successful application of these shoreline treatment options has been demonstrated at two spill events (the Tampa Bay response in Florida and the Sea Empress operation in Wales) and at a controlled oil spill experiment in the field (the 1997 Svalbard ITOSS program). Sediment relocation harnesses the hydraulic action of waves so that the processes of fine-particle interaction and physical abrasion usually occur in tandem on open coasts. There has been no evidence of significant detrimental side-effects of residual oil in pelagic or benthic environments associated with the use of these treatment options to enhance rates of dispersion and oil biodegradation.

Centrifugal Pump Effect on Average Particle Diameter of Oil-Water Emulsion

NASA Astrophysics Data System (ADS)

Morozova, A.; Eskin, A.

2017-11-01

In this paper we review the process of oil-water emulsion particles fragmentation in a turbulent flow created by a centrifugal pump. We examined the influence of time necessary for oil-water emulsion preparation on the particle size of oil products and the dependence of a centrifugal pump emulsifying capacity on the initial emulsion dispersion. The investigated emulsion contained the brand fuel oil M-100 and tap water; it was sprayed with a nozzle in a gas-water flare. After preparation of the emulsion, the centrifugal pump was turned on and the emulsion samples were taken before and after the pump passing in 15, 30 and 45 minutes of spraying. To determine the effect the centrifugal pump has on the dispersion of the oil-water emulsion, the mean particle diameter of the emulsion particles was determined by the optical and microscopic method before and after the pump passing. A dispersion analysis of the particles contained in the emulsion was carried out by a laser diffraction analyzer. By analyzing the pictures of the emulsion samples, it was determined that after the centrifugal pump operation a particle size of oil products decreases. This result is also confirmed by the distribution of the obtained analyzer where the content of fine particles with a diameter less than 10 μm increased from 12% to 23%. In case of increasing emulsion preparation time, a particle size of petroleum products also decreases.

Chemical and Phase Composition of Powders Obtained by Electroerosion Dispersion from WC - Co Alloys

NASA Astrophysics Data System (ADS)

Putintseva, M. N.

2004-03-01

The dependence of the chemical and phase composition of dispersed powders on the mode and medium of electroerosion dispersion and the content of cobalt in the initial alloy is considered. It is shown that the dissociation of carbon from tungsten carbide occurs even in dispersion in liquid hydrocarbon-bearing media (kerosene and industrial oils). The phase composition is primarily determined by the dispersion medium and the content of cobalt in the initial alloy. Compound tungsten-cobalt carbides and even a Co7W6 intermetallic are determined in all the powders.

Dispersive microextraction based on water-coated Fe₃O₄ followed by gas chromatography-mass spectrometry for determination of 3-monochloropropane-1,2-diol in edible oils.

PubMed

Zhao, Qin; Wei, Fang; Xiao, Neng; Yu, Qiong-Wei; Yuan, Bi-Feng; Feng, Yu-Qi

2012-06-01

In the present work, we developed a novel dispersive microextraction technique by combining the advantages of liquid-phase microextraction (LPME) and magnetic solid-phase extraction (MSPE). In this method, trace amount of water directly absorbed on bare Fe₃O₄ to form water-coated Fe₃O₄ (W-Fe₃O₄) and rapid extraction can be achieved while W-Fe₃O₄ dispersed in the sample solution. The analyte adsorbed W-Fe₃O₄ can be easily collected and isolated from sample solution by application of a magnet. It was worth noting that in the proposed method water was used as extractant and Fe₃O₄ served as the supporter and retriever of water. The performance of the method was evaluated by extraction of 3-monochloropropane-1,2-diol (3-MCPD) from edible oils. The extracted 3-MCPD was then derived by a silylanization reagent (1-trimethylsilylimidazole) before gas chromatography-mass spectrometry (GC-MS) analysis. Several parameters that affected the extraction and derivatization efficiency were investigated. Our results showed that the limit of detection for 3-MCPD was 1.1 ng/g. The recoveries in spiked oil samples were in the range of 70.0-104.9% with the RSDs less than 5.6% (intra-day) and 6.4% (inter-day). Taken together, the simple, rapid and cost-effective method developed in current study, offers a potential application for the extraction and preconcentration of hydrophilic analytes from complex fatty samples. Copyright © 2012 Elsevier B.V. All rights reserved.

Comparative risk assessment of spill response options for a deepwater oil well blowout: Part III. Stakeholder engagement.

PubMed

Walker, Ann Hayward; Scholz, Debra; McPeek, Melinda; French-McCay, Deborah; Rowe, Jill; Bock, Michael; Robinson, Hilary; Wenning, Richard

2018-05-25

This paper describes oil spill stakeholder engagement in a recent comparative risk assessment (CRA) project that examined the tradeoffs associated with a hypothetical offshore well blowout in the Gulf of Mexico, with a specific focus on subsea dispersant injection (SSDI) at the wellhead. SSDI is a new technology deployed during the Deepwater Horizon (DWH) oil spill response. Oil spill stakeholders include decision makers, who will consider whether to integrate SSDI into future tradeoff decisions. This CRA considered the tradeoffs associated with three sets of response strategies: (1) no intervention; (2) mechanical recovery, in-situ burning, and surface dispersants; and, (3) SSDI in addition to responses in (2). For context, the paper begins with a historical review of U.S. policy and engagement with oil spill stakeholders regarding dispersants. Stakeholder activities throughout the project involved decision-maker representatives and their advisors to inform the approach and consider CRA utility in future oil spill preparedness. Copyright © 2018 Elsevier Ltd. All rights reserved.

Development of airborne oil thickness measurements.

PubMed

Brown, Carl E; Fingas, Mervin F

2003-01-01

A laboratory sensor has now been developed to measure the absolute thickness of oil on water slicks. This prototype oil slick thickness measurement system is known as the laser-ultrasonic remote sensing of oil thickness (LURSOT) sensor. This laser opto-acoustic sensor is the initial step in the ultimate goal of providing an airborne sensor with the ability to remotely measure oil-on-water slick thickness. The LURSOT sensor employs three lasers to produce and measure the time-of-flight of ultrasonic waves in oil and hence provide a direct measurement of oil slick thickness. The successful application of this technology to the measurement of oil slick thickness will benefit the scientific community as a whole by providing information about the dynamics of oil slick spreading and the spill responder by providing a measurement of the effectiveness of spill countermeasures such as dispersant application and in situ burning. This paper will provide a review of early developments and discuss the current state-of-the-art in the field of oil slick thickness measurement.

Exposure of European sea bass (Dicentrarchus labrax) to chemically dispersed oil has a chronic residual effect on hypoxia tolerance but not aerobic scope.

PubMed

Zhang, Yangfan; Mauduit, Florian; Farrell, Anthony P; Chabot, Denis; Ollivier, Hélène; Rio-Cabello, Adrien; Le Floch, Stéphane; Claireaux, Guy

2017-10-01

We tested the hypothesis that the chronic residual effects of an acute exposure of European sea bass (Dicentrarchus labrax) to chemically dispersed crude oil is manifest in indices of hypoxic performance rather than aerobic performance. Sea bass were pre-screened with a hypoxia challenge test to establish their incipient lethal oxygen saturation (ILOS), but on discovering a wide breadth for individual ILOS values (2.6-11.0% O 2 saturation), fish were subsequently subdivided into either hypoxia sensitive (HS) or hypoxia tolerant (HT) phenotypes, traits that were shown to be experimentally repeatable. The HT phenotype had a lower ILOS and critical oxygen saturation (O 2crit ) compared with the HS phenotype and switched to glycolytic metabolism at a lower dissolved oxygen, even though both phenotypes accumulated lactate and glucose to the same plasma concentrations at ILOS. As initially hypothesized, and regardless of the phenotype considered, we found no residual effect of oil on any of the indices of aerobic performance. Contrary to our hypothesis, however, oil exposure had no residual effect on any of the indices of hypoxic performance in the HS phenotype. In the HT phenotype, on the other hand, oil exposure had residual effects as illustrated by the impaired repeatability of hypoxia tolerance and also by the 24% increase in O 2crit , the 40% increase in scope for oxygen deficit, the 17% increase in factorial scope for oxygen deficit and the 57% increase in accumulated oxygen deficit. Thus, sea bass with a HT phenotype remained chronically impaired for a minimum of 167days following an acute 24-h oil exposure while the HS phenotypes did not. We reasoned that impaired oxygen extraction at gill due to oil exposure activates glycolytic metabolism at a higher dissolved oxygen, conferring on the HT phenotype an inferior hypoxia resistance that might eventually compromise their ability to survive hypoxic episodes. Crown Copyright © 2017. Published by Elsevier B.V. All

Oil and Hazardous Materials Spill Response Technology Development, Strategic Plan

DTIC Science & Technology

2012-05-01

the pollutant can be recovered, burned, or dispersed . Objectives:  Develop the means to divert and contain sinking and suspended oils in order to...Research and Development Center 1 Chelsea Street New London, CT 06320 10. Work Unit No. (TRAIS) 11. Contract or Grant No. 12...similar analysis of prevention efforts should be carried out in the future. 17. Key Words oil, hazardous material, oil spill, pollution

Flow separation characteristics of unstable dispersions

NASA Astrophysics Data System (ADS)

Voulgaropoulos, Victor; Zhai, Lusheng; Angeli, Panagiota

2016-11-01

Drops of a low viscosity oil are introduced through a multi-capillary inlet during the flow of water in a horizontal pipe. The flow rates of the continuous water phase are kept in the turbulent region while the droplets are injected at similar flow rates (with oil fractions ranging from 0.15 to 0.60). The acrylic pipe (ID of 37mm) is approximately 7m long. Measurements are conducted at three different axial locations to illustrate how the flow structures are formed and develop along the pipe. Initial observations are made on the flow patterns through high-speed imaging. Stratification is observed for the flow rates studied, indicating that the turbulent dispersive forces are lower than the gravity ones. These results are complemented with a tomography system acquiring measurements at the same locations and giving the cross-sectional hold-up. The coalescence dynamics are strong in the dense-packed drop layer and thus measurements with a dual-conductance probe are conducted to capture any drop size changes. It is found that the drop size variations depend on the spatial configuration of the drops, the initial drop size along with the continuous and dispersed phase velocities. Project funded under Chevron Energy Technology.

Removal of oil and oil sheen from produced water by pressure-assisted ozonation and sand filtration.

PubMed

Cha, Zhixiong; Lin, Cheng-Fang; Cheng, Chia-Jung; Andy Hong, P K

2010-01-01

Ever increasing energy demand worldwide necessitates energy supply, inevitably leading to an increasing volume of process waters containing hydrocarbon contaminants. Among them, dispersed and dissolved oils in produced water need to be removed adequately in order to reuse or avoid surface sheen from coastal discharge. We have recently developed a new ozonation technique coupled with sand filtration to quickly remove oil from process water and prevent oil sheen. The technique incorporates rapid, successive cycles of compression and decompression during ozonation. Gas bubbles expanding from small to large sizes occur that provide ample reactive zones at the gas-liquid interface, resulting in heightened chemical conversions-notably the conversion of hydrophobic hydrocarbon molecules into hydrophilic ones. This study examined the removal of hydrocarbons and sheen according to treatment parameters and configurations, as assessed by changes in turbidity, COD, BOD, and sheen presence following treatment. When a synthetic produced water containing 120ppm of oil (about 100ppm of dispersed and 20ppm of soluble oil at a total COD of 320mgL(-1)) was subjected to 10 pressure cycles (reaching 1.0MPa; 20s each) of ozonation and sand filtration at 6cmmin(-1) and then repeated by 20 cycles of ozonation and sand filtration, it resulted in removal of oil to 20ppm as water-soluble organic acids, decrease of turbidity from 200 to 2NTU, and complete sequestration of surface sheen. The new technique offers a treatment alternative for produced water and likely other tailings waters, promoting safe discharge to the environment and beneficial uses of the water. 2009 Elsevier Ltd. All rights reserved.