scholarly journals Multilevel responses of adult zebrafish to crude and chemically dispersed oil exposure

2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Ada Esteban-Sánchez ◽  
Sarah Johann ◽  
Dennis Bilbao ◽  
Ailette Prieto ◽  
Henner Hollert ◽  
...  
Keyword(s):  
Oil Spills ◽  
Fold Increase ◽  
Fish Mortality ◽  
Activity Levels ◽  
Adult Zebrafish ◽  
Biological Organization ◽  
Response Strategies ◽  
Chemical Dispersant ◽  
Dispersed Oil ◽  
Water Accommodated Fractions

Abstract Background The application of chemical dispersants is a common remediation strategy when accidental oil spills occur in aquatic environments. Breaking down the oil slick into small droplets, dispersants facilitate the increase of particulate and dissolved oil compounds, enhancing the bioavailability of toxic oil constituents. The aim of the present work was to explore the effects of water accommodated fractions (WAF) of a naphthenic North Sea crude oil produced with and without the addition of the chemical dispersant FINASOL OSR 52 to adult zebrafish exposed for 3 and 21 d. Fish were exposed to environmentally relevant concentrations of 5% and 25% WAFOIL (1:200) and to 5% WAFOIL+D (dispersant–oil ratio 1:10) in a semi-static exposure setup. Results The chemically dispersed WAF presented a 20-fold increase of target polycyclic aromatic hydrocarbons (PAHs) in the water phase compared to the corresponding treatment without dispersant and was the only treatment resulting in markedly bioaccumulation of PAHs in carcass after 21 d compared to the control. Furthermore, only 5% WAFOIL+D caused fish mortality. In general, the undispersed oil treatments did not lead to significant effects compared to control, while the dispersed oil induced significant alterations at gene transcription and enzyme activity levels. Significant up-regulation of biotransformation and oxidative stress response genes (cyp1a, gstp1, sod1 and gpx1a) was recorded in the livers. For the same group, a significant increment in EROD activity was detected in liver along with significant increased GST and CAT activities in gills. The addition of the chemical dispersant also reduced brain AChE activity and showed a potential genotoxic effect as indicated by the increased frequency of micronuclei in erythrocytes after 21 d of exposure. Conclusions The results demonstrate that the addition of chemical dispersants accentuates the effect of toxic compounds present in oil as it increases PAH bioavailability resulting in diverse alterations on different levels of biological organization in zebrafish. Furthermore, the study emphasizes the importance to combine multilevel endpoints for a reliable risk assessment due to high variable biomarker responses. The present results of dispersant impact on oil toxicity can support decision making for oil spill response strategies.

scholarly journals Effects of Chemical Dispersant on the Surface Properties of Kaolin and Aggregation with Spilled Oil

2021 ◽  
Author(s):  
Wenxin Li ◽  
Yue Yu ◽  
Deqi Xiong ◽  
Zhixin Qi ◽  
Sinan Fu ◽  
...  
Keyword(s):  
Crude Oil ◽  
Surface Properties ◽  
Oil Spills ◽  
Size Ratio ◽  
Small Scale ◽  
Oil Droplets ◽  
Mineral Aggregate ◽  
Chemical Dispersant ◽  
Dispersed Oil ◽  
Spilled Oil

Abstract After oil spills occur, dispersed oil droplets can collide with suspended particles in the water column to form the oil-mineral aggregate (OMA) and settle to the seafloor. However, only a few studies have concerned the effect of chemical dispersant on this process. In this paper, the mechanism by which dispersant affects the surface properties of kaolin as well as the viscosity and oil-seawater interfacial tension (IFTow) of Roncador crude oil were separately investigated by small scale tests. The results indicated that the presence of dispersant impairs the zeta potential and enhances the hydrophobicity of kaolin. The viscosity of Roncador crude oil rose slightly as the dosage of dispersant increased while IFTow decreased significantly. Furthermore, the oil dispersion and OMA formation at different dispersant-to-oil ratio (DOR) were evaluated in a wave tank. When DOR was less than 1:40, the oil enhancement of dispersant was not significant. In comparison, it began to contribute when DOR was over 1:40 and the effect became more pronounced with the increasing DOR. The adhesion between oil droplets and kaolin was inhibited with the increasing DOR. The size ratio between oil droplets and particles is the significant factor for OMA formation. The closer the oil-mineral size ratio is to 1, the more difficultly the OMA forms.

scholarly journals Estimating the Usefulness of Chemical Dispersant to Treat Surface Spills of Oil Sands Products

2018 ◽  
Vol 6 (4) ◽  
pp. 128 ◽  
Author(s):  
Thomas King ◽  
Brian Robinson ◽  
Scott Ryan ◽  
Kenneth Lee ◽  
Michel Boufadel ◽  
...  
Keyword(s):  
Oil Sands ◽  
Oil Spills ◽  
Breaking Waves ◽  
Oil Viscosity ◽  
Chemical Dispersant ◽  
Dispersed Oil ◽  
Initial Release ◽  
Order Of Magnitude ◽  
Chemically Dispersed Oil ◽  
The Impact

This study examines the use of chemical dispersant to treat an oil spill after the initial release. The natural and chemically enhanced dispersion of four oil products (dilbit, dilynbit, synbit and conventional crude) were investigated in a wave tank. Experiments were conducted in spring and summer to capture the impact of temperature, and the conditions in the tank were of breaking waves with a wave height of 0.4 m. The results showed that natural dispersion effectiveness (DE) was less than 10%. But the application of dispersant increased the DE by an order of magnitude with a statistically significant level (p < 0.05). Season (spring versus summer) had an effect on chemical DE of all oils, except for the conventional oil. Thus, the DE of dilbit products is highly dependent on the season/temperature. A model was fitted to the DE as a function of oil viscosity for the chemically dispersed oil, and the correlation was found to be very good. The model was then combined with a previous model compiled by the author predicting oil viscosity as a function of time, to produce a model that predicts the DE as function of time. Such a relation could be used for responders tackling oil spills.

Proline utilization in Saccharomyces cerevisiae: analysis of the cloned PUT2 gene

1983 ◽  
Vol 3 (10) ◽  
pp. 1846-1856
Author(s):  
M C Brandriss
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Recombinant Dna ◽  
Fold Increase ◽  
Activity Levels ◽  
Mrna Levels ◽  
S1 Nuclease ◽  
Proline Utilization ◽  
Cloned Gene ◽  
His3 Gene ◽  
Specific Mrna

The PUT2 gene was isolated on a 6.5-kilobase insert of a recombinant DNA plasmid by functional complementation of a put2 (delta 1-pyrroline-5-carboxylate dehydrogenase-deficient) mutation in Saccharomyces cerevisiae. Its identity was confirmed by a gene disruption technique in which the chromosomal PUT2+ gene was replaced by plasmid DNA carrying the put2 gene into which the S. cerevisiae HIS3+ gene had been inserted. The cloned PUT2 gene was used to probe specific mRNA levels: full induction of the PUT2 gene resulted in a 15-fold increase over the uninduced level. The PUT2-specific mRNA was approximately 2 kilobases in length and was used in S1 nuclease protection experiments to locate the gene to a 3-kilobase HindIII fragment. When delta 1-pyrroline-5-carboxylate dehydrogenase activity levels were measured in strains carrying the original plasmid, as well as in subclones, similar induction ratios were found as compared with enzyme levels in haploid yeast strains. Effects due to increased copy number or position were also seen. The cloned gene on a 2 mu-containing vector was used to map the PUT2 gene to chromosome VIII.

scholarly journals Development of an Algorithm for Chemically Dispersed Oil Spills

2020 ◽  
Vol 7 ◽  
Author(s):  
Merv F. Fingas ◽  
Kaan Yetilmezsoy ◽  
Majid Bahramian
Keyword(s):  
Wind Speed ◽  
Water Column ◽  
Oil Spills ◽  
Regression Equations ◽  
Oil Viscosity ◽  
Mixing Depth ◽  
Chemical Dispersion ◽  
Closed Form Solutions ◽  
Dispersed Oil ◽  
Chemically Dispersed Oil

An algorithm utilizing four basic processes was described for chemical oil spill dispersion. Initial dispersion was calculated using a modified Delvigne equation adjusted to chemical dispersion, then the dispersion was distributed over the mixing depth, as predicted by the wave height. Then the droplets rise to the surface according to Stokes’ law. Oil on the surface, from the rising oil and that undispersed, is re-dispersed. The droplets in the water column are subject to coalescence as governed by the Smoluchowski equation. A loss is invoked to account for the production of small droplets that rise slowly and are not re-integrated with the main surface slick. The droplets become less dispersible as time proceeds because of increased viscosity through weathering, and by increased droplet size by coalescence. These droplets rise faster as time progresses because of the increased size. Closed form solutions were provided to allow practical limits of dispersibility given inputs of oil viscosity and wind speed. Discrete solutions were given to calculate the amount of oil in the water column at specified points of time. Regression equations were provided to estimate oil in the water column at a given time with the wind speed and oil viscosity. The models indicated that the most important factor related to the amount of dispersion, was the mixing depth of the sea as predicted from wind speed. The second most important factor was the viscosity of the starting oil. The algorithm predicted the maximum viscosity that would be dispersed given wind conditions. Simplified prediction equations were created using regression.

EFFECTIVENESS, BEHAVIOR, AND TOXICITY OF DISPERSANTS

1983 ◽  
Vol 1983 (1) ◽  
pp. 65-71 ◽  
Author(s):  
Donald Mackay ◽  
Peter G. Wells
Keyword(s):  
Water Column ◽  
Oil Spills ◽  
Current Status ◽  
Dispersed Oil ◽  
Chemical Studies ◽  
Key Issues ◽  
Oil Emulsions ◽  
Dispersant Effectiveness ◽  
Individual Hydrocarbons ◽  
Physical And Chemical

ABSTRACT Three key issues must be addressed when deciding on the desirability of using chemical dispersants for mitigating the adverse effects of oil spills: (1) how effective a given dosage of dispersant will be on a given oil slick; (2) how the dispersed oil and dispersant diffuse into the water column, dissolve, volatilize, degrade, and interact with suspended and bottom sediments; and (3) what effects the dissolved and particulate oil and dispersant will have on water column and benthic biota. It is essential that the first two areas (physical and chemical studies) relate closely to the third (biological aspects) in order that bioassay exposure (in terms of concentration of dispersant, classes of and individual hydrocarbons, and duration) addressing the toxicity issue be realistic. Here, we review the current status of a research program which addresses these issues. Under the program, attempts are being made to quantify dispersant effectiveness (including consideration of effectiveness testing using the Mackay-Nadeau-Steelman system for oils which have evaporated and/or formed water-in-oil emulsions to various extents), water column diffusion, and partitioning of specific hydrocarbons among water, oil, and suspended sediment as well as into the atmosphere. A procedure is described which has been used to quantify the acute toxicity of dispersants to copepods and which is being extended to apply also to the toxic contributions of dissolved and particulate oil. Hopefully, by assembling quantitative expressions for effectiveness, behavior, and toxicity, those situations in which dispersion is desirable can be better identified.

Recent Results from Oil Spill Response Research

1991 ◽  
Vol 1991 (1) ◽  
pp. 673-676
Author(s):  
Edward Tennyson
Keyword(s):  
Oil Spill ◽  
Oil Spills ◽  
Management Service ◽  
Research Projects ◽  
Response Strategies ◽  
Yield Information ◽  
Environmental Test ◽  
Oil Spill Response ◽  
Spilled Oil

ABSTRACT Recent large oil spills from tankers have reaffirmed the need for continuing technology assessment and research to improve oil-spill response capabilities. The Minerals Management Service (MMS) remains a lead agency in conducting these studies. This paper discusses MMS concerns, as reinforced by the acceleration of its research program in 1990. It briefly assesses the current state-of-the-art technology for major aspects of spill response, including remote sensing, open-ocean containment, recovery, in-situ burning, chemical treating agents, beach-line cleanup, and oil behavior. The paper reports on specific research projects that have begun to yield information that will improve detection and at-sea equipment performance. The first detection project, for which MMS has patent pending, involves the use of shipboard navigational radar to track slicks at relatively long range. The second project involves the use of conventional containment and cleanup in a downwind mode, which is contrary to the traditional procedures. The paper also discusses current research projects, including the development of an airborne, laser-assisted fluorosensor that can determine whether apparent slicks contain oil. Additional projects involve the development of improved strategies for responding to oil in broken-ice conditions, for gaining an improved understanding of the fate and behavior of spilled oil as it affects response strategies, and for reopening and operating the oil and hazardous materials simulated environmental test tank (OHMSETT) facility in Leonardo, New Jersey. Recent progress on the development of safe and environmentally acceptable strategies to burn spilled oil in-situ is also discussed. The OHMSETT facility is necessary for testing prospective improvements in chemical treating agents and to develop standard procedures for testing and evaluating response equipment.

OIL SPILL CLEANUP WITH DISPERSANTS: A BOOMED OIL SPILL EXPERIMENT

1981 ◽  
Vol 1981 (1) ◽  
pp. 263-268
Author(s):  
Joseph Buckley ◽  
David Green ◽  
Blair Humphrey
Keyword(s):  
Water Column ◽  
Oil Spill ◽  
Oil Spills ◽  
Sea Water ◽  
Visual Observation ◽  
Oil Droplets ◽  
Oil Boom ◽  
Dispersed Oil ◽  
Vertical Density ◽  
Oil Spill Cleanup

ABSTRACT Three experimental oil spills of 200, 400, and 200 litres (l) were conducted in October, 1978, in a semiprotected coastal area on Canada's west coast. The surface slicks were restrained with a Bennett inshore oil boom. The spilled oil was chemically dispersed using Corexit 9527, applied as a 10-percent solution in sea water and sprayed from a boat. The dispersed oil was monitored fluorometrically for some hours. Surface and dispersed oil were sampled for chemical analysis. The highest recorded concentration of dispersed oil was 1 part per million (ppm). After a short time (30 minutes), concentrations around 0.05 ppm were normal, decreasing to background within 5 hours. The concentrations were low compared to those expected for complete dispersion which, as visual observation confirmed, was not achieved. The dispersed oil did not mix deeper into the water column with the passage of time, in contrast to predicted behaviour and in spite of the lack of a significant vertical density gradient in the sea water. This was attributed to the buoyancy of the dispersed oil droplets and the limited vertical turbulence in the coastal locale of the experiment. The integrated quantity of oil in the water column decreased more rapidly than either the mean oil concentration of the cloud or the maximum concentration indicating that some of the dispersed oil was rising back to the surface. The surfacing of dispersed oil was confirmed visually during the experiment. The mixing action of the spray boat and breaker boards apparently created large oil droplets that did not form a stable dispersion. Horizontal diffusion of the dispersed oil was initially more rapid than expected, but the rate of spreading did not increase with time as predicted. The results imply that the scale of diffusion was larger than the scale of turbulence which again can be attributed to the locale of the experiment.

DEVELOPMENT AND APPLICATION OF DTox: A QUANTITATIVE DATABASE OF THE TOXICITY OF DISPERSANTS AND CHEMICALLY DISPERSED OIL

2014 ◽  
Vol 2014 (1) ◽  
pp. 733-746 ◽  
Author(s):  
Adriana C. Bejarano ◽  
Valerie Chu ◽  
Jeff Dahlin ◽  
Jim Farr
Keyword(s):  
Oil Spill ◽  
Oil Spills ◽  
Biological Effects ◽  
Life Stage ◽  
Data Repository ◽  
Toxicity Data ◽  
Dispersed Oil ◽  
Chemically Dispersed Oil ◽  
Data Source ◽  
High Concentrations

ABSTRACT The Deepwater Horizon oil spill revived discussions on the use of dispersants as an oil spill countermeasure. One of the greatest concerns regarding the use of dispersants deals with potential exposure of water column organisms to high concentrations of oil. While toxicity data on dispersants and physically and chemically dispersed oil have been generated for decades under controlled laboratory conditions, the practical use of this information has been limited by the lack of a centralized data repository. As a result, the Dispersant and Chemically Dispersed Oil Toxicity Database (DTox) was created to address that shared need of unrestricted and rapid access to toxicity data. DTox is a quantitative database that gathers existing toxicity data through a careful review and compilation of data extracted from the peer-review and gray literature. Through a rigorously evaluation of the quality of each data source, this database contains pertinent information including species scientific name, life stage tested, dispersant name, exposure type, oil weathering stage, exposure duration, etc. More importantly, this database contains effects concentrations reported on measured or nominal basis. Within the database, each data source is assigned an applicability score based on their relevance to oil spills. Key criteria in the determination of source applicability include exposure type, reported effects concentrations, and reported analytical chemistry. Information in DTox has been further integrated into a user-friendly tool that allows for on-the-fly data searches and data plotting in the form of Species Sensitivity Distributions. To date, +400 papers have been evaluated for potential inclusion into the database, and data extracted from +170 sources. Despite inherent limitations, existing toxicity data are of great value to the oil spill scientific community. Although toxicity data will never be enough to answer all toxicity questions regarding the use of dispersants, this centralized data repository can help inform decisions on dispersant use and can help identify data needs and gaps. The ultimate goal of this tool is its contribution to a better understanding of the biological effects of dispersants and oil in the aquatic environment.

Optimizing Offshore Combat of Oil Spills – Development of New Booms and Helicopter Based Application of Dispersants

2003 ◽  
Vol 2003 (1) ◽  
pp. 1279-1284
Author(s):  
Tharald M. Brekne ◽  
Sigmund Holmemo ◽  
Geir M. Skeie
Keyword(s):  
Oil Spill ◽  
Oil Spills ◽  
New Technology ◽  
Geographic Location ◽  
Chemical Dispersant ◽  
Offshore Installations ◽  
The Status ◽  
Oil Spill Response ◽  
Robust Systems ◽  
Norwegian Continental Shelf

ABSTRACT There is an increasing focus on offshore combat of oil spills on the Norwegian Continental Shelf (NCS). One result of this focus is a change from field specific to area specific contingency, moving from many medium sized oil spill combat vessels, to fewer and more robust systems and vessels. An important element in the emerging configuration is the use of helicopter based chemical dispersant systems, permanently located on offshore installations. An increasing diversity, of oil types being produced, configuration of installations, water depths and geographic location, are all factors that require a robust, mobile and flexible oil spill response. The Norwegian Clean Seas Association for Operating Companies (NOFO) has recently initiated development of new technology, as projects under NOFO's Research & Development Programme. Three of these projects address the development of improved heavy offshore booms, applying new principles for containment of oil, and a heavy duty skimmer optimized for mobility. A fourth project addresses the development of a system for helicopter based application of chemical dispersants, optimized for offshore storage and maintenance. This paper presents the status for and experience from these projects, as well as the plan for testing and verification of this new technology.

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