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The essential target of academics and the industrial sector is the innovation of an industrial ecology approach. Worldwide, cigarette butts (CBs) comprise the most predominant form of litter that spreads into the ecosystem and inland. In the meantime, oil is spilled into marine life from various activities and transportation. The result is a complex oil–water composition in a high concentration that causes severe hazards to the environment and to aquatic life. In this regard, the current investigation focuses on obtaining hydrophobic cellulose acetate from CBs for use as a filter media. The filter is applied in marine oil spill separation as a win–win industrial ecology technique. Initially, the separated CB residuals were prepared by successive washing. Subsequently, the obtained cellulose acetate fibers were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Furthermore, the new CB-based filters were used in the separation/adsorption of marine oil wastewater spill. Subsequently, a group of experiments were conducted. The results showed that the cleanup efficiency could be up to 99% in terms of chemical oxygen demand (COD). Moreover, the products were recovered by washing with hot water for further use, which showed high removal activity that reached 95% after successive uses. In comparison to commercial oil sorption materials, the results were promising as the RP-C18 cartridge revealed a maximum oil removal of 90%. Such preliminary data on a cellulose acetate filter scheme are a good indicator in the development of an oil spill facility, being a suitable candidate for controlling oil wastewater effluent streams. [ABSTRACT FROM AUTHOR]

The marine environment is a vast, complex and assorted ecosystem. This ecosystem plays an essential role in the functioning of the earth. It contains a wide range of living and non-living components. It facilitates nutrient cycling, habitat formation, world climate regulation. Unfortunately, marine pollution is a serious environmental threat that badly impacts on marine life and ecosystems. Among the verities of pollutant, oil is one of the most detrimental to the marine life and human. In this review, the impact of oil pollution, different sources of oil pollution, composition of oil, fate of oil pollution and different methods of oil clean up were covered. [ABSTRACT FROM AUTHOR]

Janus nanoparticles have aroused the interest of scholars because of their highly efficient emulsification of spilled oils in wastewater. In this work, interfacially active Janus hollow glass microparticles (J-HGMPs) of asymmetric wettability were designed and synthesized in order to achieve more efficient separation of emulsified oil droplets from oily wastewater. Surface characteristic techniques such as FTIR, SEM, zeta potential and contact angle measurements had been employed to assess the amphiphilic surface properties of J-HGMPs. The oil removal/recovery performance of J-HGMPs in different oil–water systems and their interfacial activities were studied. As a particulate emulsifier, J-HGMPs could remove/recover > 96% oil from oil–water mixed phase. The results showed that J-HGMPs had strong interfacial activities and anchored firmly at oil/water interfaces. This high adsorption energy was also evaluated and verified via the calculation of Gibbs free energy. Overall, this study provided a novel and low-cost oil recovery method via a convenient buoyancy force that could be effectively applied in the treatment of oil spills while achieving the goal of benign and green environmental protection. [ABSTRACT FROM AUTHOR]

The offshore oil industry in Atlantic Canada necessitates a greater understanding of the potential impacts of oil exposure and spill response measures on cold‐water marine species. We used a standardized scoring index to characterize sublethal developmental impacts of physically and chemically dispersed crude oil in early life stages of Atlantic cod (Gadus morhua) and assessed intraspecific variation in the response among cod families. Cod (origin: Scotian Shelf, Canada) were laboratory‐crossed to produce embryos from five specific families, which were subsequently exposed prehatch to gradient dilutions of a water‐accommodated fraction (WAF) and a chemically enhanced WAF (CEWAF; prepared with Corexit 9500A) for 24 h. Postexposure, live embryos were transferred into filtered seawater and monitored to hatch; then, all live fish had sublethal endpoints assessed using the blue‐sac disease (BSD) severity index. In both WAF and CEWAF groups, increasing exposure concentrations (measured as total petroleum hydrocarbons) resulted in an increased incidence of BSD symptoms (impaired swimming ability, increased degree of spinal curvature, yolk‐sac edemas) in cod across all families. This positive concentration‐dependent increase in BSD was similar between physically (WAF) versus chemically (CEWAF) dispersed oil exposures, indicating that dispersant addition does not exacerbate the effect of crude oil on BSD incidence in cod. Sensitivity varied between families, with some families having less BSD than others with increasing exposure concentrations. To our knowledge, our study is the first to demonstrate the occurrence in fishes of intraspecific variation among families in sublethal responses to oil and dispersant exposure. Our results suggest that sublethal effects of crude oil exposure will not be uniformly observed across cod populations and that sensitivity depends on genetic background. Environ Toxicol Chem 2022;41:1967–1976. © 2022 SETAC [ABSTRACT FROM AUTHOR]

Oil spills in open waters pose a significant threat to marine life. The application of dispersant as an oil-spill response is a promising approach to minimize the environmental burden caused by these accidental events. Dispersants have been accepted and applied by many countries around the world as a countermeasure in responding to oil spills due to their great success and advancements in recent years. This review covers different approaches for design and development of chemical formulas of oil dispersants with the aim to improve dispersing efficiencies, followed by formulating non-chemical dispersants, which are more environmentally friendly approaches. The encouraging properties motivate scientific communities to research and develop these non-chemical-based dispersants. In general, this review intends to offer a multi-perspective overall picture of progress made in recent years to develop and apply different dispersants suitable for combating oil spills. [ABSTRACT FROM AUTHOR]

The use of chemical dispersants is one of the most widely used methods for responding to oil spills. The most important characteristic of dispersants is their effectiveness. The dispersant effectiveness is a measure of how well the dispersant breaks up and stabilizes the oil into the water column. In this paper, we studied the dispersing ability of three proprietary dispersants with respect to light and heavy crude oils of Usinsk and Nagornoye fields with a density of 0.816 g/cm³ and 0.896 g/cm³, respectively. The dispersant effectiveness was determined using a Baffled Flask Test; dispersant was applied to the oil slick, mixed, and the concentration of oil in a sample taken from the water column was measured using UV-Visible spectrophotometry. A modification of the standard technique is proposed to minimize the error of the method for the heavy crude oil by eliminating the error associated with inaccuracy of dosing. For this purpose, oil of the Nagornoye field was added to the tested systems not "by volume", but "by weight". It was provided better convergence of the experimental results. The standard deviation in the case of dosing of oil "by volume" exceeded 10% and varied from 11.87% to 13.59%. The introduction of oil "by weight" was much lower and varied from 5.66% to 6.30%. Studied dispersants have a higher dispersing ability for the less dense oil of the Usinsk field. [ABSTRACT FROM AUTHOR]

Thousands of oil spill incidents regrettably have occurred on a daily basis around the globe. Oil spills are a form of pollution that poses major catastrophic threats to marine ecosystems. Oil spill incidents commonly occur in the middle of the ocean, and the process to remove the oil becomes a great challenge. Absorbents, due to their good oil-absorbing characteristics, are becoming more popular nowadays as one of the effective oil spill clean-up methods. Among the many types of oil absorbents, plant fibers were also being studied to remove the oil spills from the sea surface. This paper reviews factors leading to oil spills, the detrimental effect of the oil spill on the environment, the oil spill removal methods, and the application of plant fibers as oil absorbent material. The paper also will highlight the latest development on the utilization of kenaf core fibers as oil-absorbent material and the use of oil absorbed kenaf core fibers as fuel briquette by taking advantage the high calorific value of the oil spill. [ABSTRACT FROM AUTHOR]

An oil spill was simulated in a basin connected to the sea, which presents inside the National Institute of Oceanography and Fisheries. Two available natural fibrous materials were used after modification as sorbent materials for the treatment of oil spills. Sorption capacities of LCLA and PFLA onto crude oil were preliminarily examined in the laboratory before applying in the field. An amount of LCLA and PFLA were wrapped in a polyester circular pad. Cylindrical-shaped acrylic vessels, with perforated sides, were fixed with cork sheets to keep them floating on the water surface. 1.1 mm thickness of light crude oil was spilled inside the acrylic vessels. LCLA and PFLA containing pads were then dipped into an oil layer floating on seawater. Pads were laid into the interface between oil and seawater for 30 min (one pad per each vessel). Sorption capacities were measured as 11.0 and 9.8 as gram oil per gram of sorbent for LCLA and PFLA, respectively. These results were close to the sorption capacities produced in the laboratory using the same oil and sorbent materials indicating that the tested sorbents have a cheerful application in the real field. [ABSTRACT FROM AUTHOR]

Aims: This study aimed to isolate and identify hydrocarbon-utilising bacteria from oil-polluted sites and to develop a microbial consortium for use in pilot trial and commercial scale bioremediation treatment systems in the future. Methodology and results: Ten hydrocarbon-utilising bacterial strains were isolated using enrichment culture technique from oil-polluted sites using crude oil as sole carbon source. The strains were tentatively identified on the basis of colony morphology, microscopic examination and biochemical characteristics. The growth of each strain was assessed by growing the bacteria in mineral salt medium amended with diesel oil as sole carbon source. The isolates exhibited differences in growth with the order of biomass production being Enterobacter sp. (OD620=1.283)> Bacillus subtilis subsp. subtilis (OD620=1.245) > Aerococcus sp. (OD620=1.100) > Bacillus firmus (OD620=0.970) > Corynebacterium sp. (OD620=0.886) > Bacillus lentus (OD620=0.743) > Micrococcus luteus (OD620=0.656) > Bacillus subtilis (OD620=0.367) > Bacillus cereus (OD620=0.110) > Kocuria flavus (OD620=0.065). Conclusion, significance and impact of study: This study is a prerequisite for the design of future full-scale bioremediation treatment of oil-polluted sites using hydrocarbon-utilising bacteria. An efficient consortium was developed comprising the best three hydrocarbon-utilising strains, which include Enterobacter sp., Bacillus subtilis subsp. subtilis and Aerococcus sp. This efficient microbial consortium is suggested to be used in future to rehabilitate oil-polluted sites in Sudan. [ABSTRACT FROM AUTHOR]

Nowadays, although dispersants have been widely applied for emergency response to oil spills, they are potentially hazardous to the marine ecosystem. Therefore, it is necessary to evaluate dispersants' toxicity in a practical and integrated way before their large-scale application. Here, we compared the acute toxicity of five chemical dispersants (concentrate RS-I, conventional RS-I, HLD-501, Fuken-2, and Weipu) to three species (a microalgae Platymonas helgolandica, a mollusk Ruditapes philippinarum, and a luminescent bacterium Acinetobacter sp. Tox2) which represent different trophic levels. Our results showed that (1) conventional RS-I was slightly toxic to all the three test organisms; (2) concentrate RS-I and Weipu were slightly toxic to R. philippinarum, but were not toxic to the other two test species; (3) Fuken-2 and HLD-501 exhibited no acute toxicity to the three test organisms. Our results could provide information on toxicity data derived from multiple test organisms for the use of these five dispersants in the future. [ABSTRACT FROM AUTHOR]

The devastating effects of oil spills on the ecosystems must be minimized by looking for effective solutions which offer a fast response to them. This work aimed at characterizing the oil-absorption capacity of flexible low-density open-cell foams based on polyolefins with different levels of tortuosity by comparing it to the one displayed by a commercial flexible open-cell polyurethane foam. The results showed that the tortuosity played a critical role in this property, absorbing the open-cell foams with low tortuosity up to 3 times more oil than the ones with high tortuosity. Oil absorptions as considerable as 43 g of oil per gram of foam were obtained, absorbing these foams up to 3.76 times more oil than the open-cell PU foam used as the reference. The hydrophobic character of these foams has also been characterized obtaining negligible water absorptions for the open-cell polyolefin-based materials, showing besides excellent oil–water selectivity. Finally, the reusability of the foams has been analyzed by using two methodologies: mechanical tests at low strain rates and by performing successive oil-absorption tests. The results indicated that open-cell EVA-based foams can be reused at least 50 times, whereas the open-cell LDPE-based foams tended to collapse. This study has proven that open-cell EVA-based foams with low tortuosity can be a potential alternative to be used in oil spill remediation. [ABSTRACT FROM AUTHOR]

Concerns on the timing and processes associated with petroleum degradation were raised after the use of Corexit during the Deepwater Horizon oil spill. There is a lack of understanding of the removal of oil associated with flocculate materials to the sediment. Mesocosm studies employing coastal and open-ocean seawater from the Gulf of Mexico were undertaken to examine changes in oil concentration and composition with time. The water accommodated fractions (WAF) and chemically enhanced WAF (CEWAF) produced using Macondo surrogate oil and Corexit were followed over 3–4 days in controlled environmental conditions. Environmental half-lives of estimated oil equivalents (EOE), polycyclic aromatic hydrocarbons (PAH), n-alkanes (C10-C35), isoprenoids pristane and phytane, and total petroleum hydrocarbons (TPH) were determined. EOE and PAH concentrations decreased exponentially following first-order decay rate kinetics. WAF, CEWAF and DCEWAF (a 10X CEWAF dilution) treatments half-lives ranged from 0.9 to 3.2 days for EOE and 0.5 to 3.3 days for PAH, agreeing with estimates from previous mesocosm and field studies. The aliphatic half-lives for CEWAF and DECWAF treatments ranged from 0.8 to 2.0 days, but no half-life for WAF could be calculated as concentrations were below the detection limits. Biodegradation occurred in all treatments based on the temporal decrease of the nC17/pristane and nC18/phytane ratios. The heterogeneity observed in all treatments was likely due to the hydrophobicity of oil and weathering processes occurring at different rates and times. The presence of dispersant did not dramatically change the half-lives of oil. Comparing degradation of oil alone as well as with dispersant present is critical to determine the fate and transport of these materials in the ocean. [ABSTRACT FROM AUTHOR]

The baffled flasks were used to simulate regular wave and breaking wave at different oscillation intensities to study the effects of wave strength, reaction time, and dispersant on the submergence of oil spill. It was found that the wave strength has the greatest impact on submerging rate and submergence stability of Liaohe crude oil and Fuel 180. The characteristics of the impacts of the wave strength and dispersant content are that there are thresholds, below which the impacts are not obvious; their coupling effects are obvious only when both the wave strength and the dispersant content exceed their threshold; the impacts can accumulate over time and have the maximum value; the submerging rate reaches maximum at 30 min for Liaohe crude oil and 60 min for Fuel 180; the submerging rate will decrease after the time of the maximum impact. Based on the experimental results, it is proposed that the submerging model should have different forms based on the thresholds of conditions and different phases of the time, which need more work to be determined for different oils. [ABSTRACT FROM AUTHOR]

An effective solution to separate oil and water is urgently needed owing to the increasingly serious problem of oil pollution. Numerous studies have been done to endow ordinary materials with extreme wettability for oil/water separation. Unfortunately, most of these materials cannot work in harsh environments, resulting in the low stability and practicability in practice. Herein, a facile method was proposed to fabricate superhydrophilic and underwater superoleophobic mesh by immersing ordinary mesh in a mixture of sulfuric acid (H2SO4) and chromium trioxide (CrO3). After immersing for just 1 min, the mesh was endowed with superhydrophilicity (CA = 0°) and underwater superoleophobicity (hexane CA = 151°, SA = 14°). Increasing the immersion time to 3 min, the prepared mesh exhibited better superoleophobicity. A separation device was developed based on the prepared mesh and the separation efficiencies for diverse oil/water mixtures containing acid, alkaline, salt and hot water were above 95%. The device retained a high efficiency after being reused for 20 times and the prepared mesh maintained superoleophobicity after immersing underwater for 72 h and abrasion test of 100 cycles. This oil/water separation method is easy-to-use, inexpensive, power-free and it can be used to separate caustic oil/water mixtures. [ABSTRACT FROM AUTHOR]

The role of advanced technologies in the remediation of oil spilled environment was investigated. Oil spill remediation technologies for the clean-up of soil and groundwater contamination from petroleum industry activities have advanced considerably over the past decade. This has been the result of increasing regulatory pressures in many parts of the world, mounting liability exposure, changing public perceptions, and the drive towards enhanced remediation in terms of cost effectiveness, health and environmental concerns, operation and maintenance requirement, applicability and efficiency. This paper examined the state of remedial technologies for petroleum industry applications in ex-situ and in-situ conditions, and used an effective score drawn from research to develop a decision matrix for selection evaluation. Ex-situ technologies involve excavation and treatment of contaminated soil. These include methods such as pyrolysis, solvent extraction, oxidation/reduction, and bioremediation, designed to remediate the soil to acceptable standards. In-situ technologies involve alteration of sub-surface flow, pressure, chemical or biological regimes to achieve containment, redirection, removal or destruction of contaminants. They include soil vapour extraction, bioventing, bio-sparging, and the use of horizontal wells and semi-passive barrier systems. A decision matrix was then developed using Microsoft Excel to aid decision making. This was developed using an effective research score allocated to each evaluation criterion and weighted using the ratio of this effective score to the total score by hundred percent. The optimal remedial approach depends on the highest ranked score as computed and documented in the MS-excel spreadsheet. From the analyses shown in the ex-situ decision matrix, advanced bioremediation was found to the best placed technique with a weighted score of 7.048 and the highest rank of 1, while wet oxidation was found to be the least impressive technique with a weighted score of 2.022. [ABSTRACT FROM AUTHOR]

The ecological and economic importance of fish act as a brake on the development of chemical dispersants as operational instruments following oil spills. Although a valuable and consistent body of knowledge exists, its use in spill response is limited. The objective of the present study was to increase current knowledge base to facilitate the translation of published data into information of operational value. Thus we investigated the dose–response relationship between dispersant‐treated oil exposure and ecologically relevant consequences by combining laboratory and field experiments. Effects were examined over almost a year using juveniles of the slowly growing, commercially important European sea bass (Dicentrarchus labrax). A reliable interpretation of biomarker responses requires a complete knowledge of the factors likely to affect them. Interpopulational variability is of particular importance in environmental impact assessment because biomarker responses from a population collected in an impacted area are classically compared with those collected in a clean site. Our study revealed no effect of the exposure to dispersant‐treated oil on fish hypoxia tolerance and temperature susceptibility at 1 and 11 mo post exposure. Similarly, no effect of the exposure was observed on the ability of the fish to cope with environmental contingencies in the field, regardless of the dose tested. Thus we feel confident to suggest that a 48‐h exposure to chemically treated oil does not affect the ability of sea bass to cope with mild environmental contingencies. Finally, investigation of interpopulation variability revealed large differences in both hypoxia tolerance and temperature susceptibility among the 2 populations tested, suggesting that this variability may blur the interpretation of population comparisons as classically practiced in impact assessment. Environ Toxicol Chem 2019;38:210–221. © 2018 SETAC [ABSTRACT FROM AUTHOR]

Following the Deepwater Horizon oil spill, eastern oyster (Crassostrea virginica) reefs in the northern Gulf of Mexico were exposed to oil and various associated clean-up activities that may have compromised oyster reef health. Included in the exposure was oil, dispersant, and in some locales, atypical salinity regimes. Oil and dispersants can be detrimental to oysters and the effects of salinity depend on the level. In addition to these extrinsic factors, genetic diversity of oyster populations may help the oysters respond to stressors, as demonstrated in other systems. We used a 3×3×2 factorial design to experimentally examine the effects of oil/dispersed oil, intraspecific genetic diversity, and salinity on juvenile (ca. 25 mm shell height) oyster survivorship and growth during a 21-d exposure in a closed, recirculating system. The genetic effect was weak overall, oil and dispersed oil negatively affected juvenile oyster survivorship, and low salinity mitigated mortality in oil and dispersed oil treatments. Survivorship was about 40% greater in low-salinity than in mesohaline water for both oil and dispersed oil treatments, bringing survivorship in low salinity oil-only treatments to a similar level with low salinity controls (no oil). Oyster growth was minimal after 21 d but appeared to be negatively affected by oil and dispersed oil, and had a significant interaction with salinity. Our results may be informative for future decisions regarding oil spill response activities and suggest that a pulse of low salinity water may be a viable short-term mitigation option for oysters if filtration characteristics, exposure time, and water temperatures are all considered, in addition to weighing the costs and benefits of this type of response on other organisms and habitats. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Chemical dispersants can be a useful tool to mitigate oil spills. This study examined potential risks to sensitive estuarine species by comparing the toxicity of two dispersants (Corexit® EC9500A and Finasol® OSR 52) individually and in chemically enhanced water-accommodated fractions (CEWAFs) of Louisiana Sweet Crude oil. Acute toxicity thresholds and sublethal biomarker responses were determined in seven species (sheepshead minnow, grass shrimp, mysid, amphipod, polychaete, hard clam, mud snail). Comparing median lethal (LC50) values for the dispersants, Finasol was generally more toxic than Corexit and had greater sublethal toxicity (impaired embryonic hatching, increased lipid peroxidation, decreased acetylcholinesterase activity). The nominal concentration-based mean LC50 for all species tested with Corexit was 150.31 mg/L compared with 43.27 mg/L with Finasol. Comparing the toxicity of the CEWAFs using the nominal concentrations (% CEWAF), Corexit-CEWAFs appeared more toxic than Finasol-CEWAFs; however, when LC50 values were calculated using measured hydrocarbon concentrations, the Finasol-CEWAFs were more toxic. There was greater dispersion efficiency leading to greater hydrocarbon concentrations measured in the Corexit-CEWAF solutions than in equivalent Finasol-CEWAF solutions. The measured concentration-based mean LC50 values for all species tested with Corexit-CEWAF were 261.96 mg/L total extractable hydrocarbons (TEH) and 2.95 mg/L total polycyclic aromatic hydrocarbons (PAH), whereas the mean LC50 values for all species tested with Finasol-CEWAF were 23.19 mg/L TEH and 0.49 mg/L total PAH. Larval life stages were generally more sensitive to dispersants and dispersed oil than adult life stages within a species. These results will help to inform management decisions regarding the use of oil-spill dispersants. [ABSTRACT FROM AUTHOR]

Oil spills over seawater and dye pollutants in water cause economic and environmental damage every year. Among various methods to deal oil spill problems, the use of porous materials has been proven as an effective strategy. In recent years, graphene-based porous sorbents have been synthesized to address the shortcomings associated with conventional sorbents such as their low uptake capacity, slow sorption rate, and non-recyclability. This article reviews the research undertaken to control oil spillage using three-dimensional (3D) graphene-based materials. The use of these materials for removal of dyes and miscellaneous environmental pollutants from water is explored and the application of various multifunctional 3D oil sorbents synthesized by surface modification technique is presented. The future prospects and limitations of these materials as sorbents are also discussed. [ABSTRACT FROM AUTHOR]

Oil pollution brings great challenge to environmental protection. Utilising oil-water separation device to separate and recycle oils is an environment-friendly approach to dispose mixtures containing oils. Pouring-type gravity-driven oil-water separation method based on extremely wettable materials is an interesting area of research because of its high separation velocity, selectivity and purity. However, the presence of water bridge results in low separation efficiency. Herein, the authors first synthesised a facile etching method and a dipcoating method to fabricate contrary extreme wettability sponges including superhydrophilic-underwater-superoleophobic (SHI-U-SOO) sponge and superhydrophobic-superoleophilic (SHO-SOI) sponge. Accordingly, they designed a three-way oil-water separation system whose left and right bottom tubes were installed with the SHI-U-SOO sponge and the SHO-SOI sponge, respectively. Water and oil separately flow out from the left and right tubes, thereby eliminating the water bridge and increasing separation efficiency, and still having ideal separation selectivity and separation purity. The developed three-way oil-water separation system has promising application prospects in disposing oil spills, oil leakage from factories and industrial effluents. [ABSTRACT FROM AUTHOR]

Oil spillage accidents can cause severe short-term effects to marine organisms and may lead to devastating long-term impact to marine environments. This study determined the influence of water accommodated fractions (WAFs) of diesel oil, chemically enhanced WAFs (CEWAFs) of diesel oil and oil dispersant (IPAC-OCD) to the toxicity of green algae, Tetraselmis chuii, and marine diatom, Chaetocheros calcitrans. Both the phytoplankton species were exposed to different concentrations of WAFs, CEWAFs and dispersant (0%, 5%, 10%, 20%, 40%, 80%). All of the toxicants significantly reduced the growth of phytoplankton, however, the level of response varied by solution and species. The dispersant has the highest impact among all the chemicals studied. The dispersant is very highly toxic to C. calcitrans, but still practically non-toxic to T. chuii. Even though, WAFs have higher impact to T. chuii than C. calcitrans, the chemicals are practically non-toxic to both phytoplankton species and, moreover, in short-term exposure, low concentration of WAFs may stimulate the growth of C. calcitrans. However, the mixture of diesel oil WAFs and dispersant cause synergistic toxicity to C. calcitrans that increases the WAFs toxicity. This finding implies that the dispersant application to mitigate the oil spills may negatively impact the marine phytoplankton. [ABSTRACT FROM AUTHOR]

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 [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. Environ Toxicol Chem 2014;33:107-114. © 2013 SETAC [ABSTRACT FROM AUTHOR]

This review covers selected 2012 articles on the biological effects of pollutants and human physical disturbances on marine and estuarine plants, animals, ecosystems and habitats. The review, based largely on journal articles, covers field and laboratory measurement activities (bioaccumulation of contaminants, field assessment surveys, toxicity testing and biomarkers) as well as pollution issues of current interest including endocrine disrupters, emerging contaminants, wastewater discharges, dredging and disposal, etc. Special emphasis is placed on effects of oil spills and marine debris due in part to the 2010 Deepwater Horizon oil blowout in the Gulf of Mexico and the 2011 Japanese tsunami. Several topical areas reviewed in the past (ballast water and ocean acidification) were dropped this year. The focus of this review is on effects, not pollutant fate and transport. There is considerable overlap across subject areas (e.g. some bioaccumulation papers may be cited in other topical categories). Please use keyword searching of the text to locate related but distributed papers. Use this review only as a guide and please consult the original papers before citing them. [ABSTRACT FROM AUTHOR]

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Oil-Spill Dispersant (OSD) reduces interfacial tensions of oil and water turning oil spill into droplets that makes crude oil easier to be degraded by hydrocarbonoclastic bacteria such as Pseudomonas aeruginosa. The purpose of this study is to assess the effect of dispersant utilization (solvent-based and water-based) related its performance efficiency in the presence of Pseudomonas aeruginosa. The research was carrried out in laboratory, varying Dispersant-Oil Ratio (DOR) into 3 levels (1:8, 1:20, 1:25) and carbon source adaptation into 3 levels (0%, 1%, 2%). The total number of samples prepared was 84, consist of 21 samples without Pseudomonas aeruginosa addition and 63 samples with Pseudomonas aeruginosa addition. Total petroleum hydrocarbon (TPH) is measured using gravimetric method to determine the biodegradation of crude oil. Also measured are pH of samples with Pseudomonas aeruginosa addition and COD (Chemical Oxygen Demand) value of samples with dispersants. Data were evaluated using ANOVA. The result shows Pseudomonas aeruginosa has the ability to degrades crude oil despite the presence of dispersant, whereas the use of water-based dispersant showed better biodegradation ability than solvent-based OSD usage. Dispersant effectiveness of solvent-based and water-based is 33% and biodegradation by Pseudomonas aeruginosa achieved 25% in 72 hours. [ABSTRACT FROM AUTHOR]

Chemical dispersion is one of the most cost-effective options to remediate oil spill at open sea. Identifying significant factors that determine in situ droplet size distributions facilitates mechanistic understanding of dispersant effectiveness. In this work, in situ dispersed oil droplet size distributions were characterized during testing of chemical dispersant effectiveness of two dispersants (Corexit 9500 and SPC 1000) on two oils [Medium South American (MESA) and Alaska North Slope (ANS)] under three wave conditions (regular nonbreaking, spilling breaking, and plunging breaking waves) in an experimental wave tank. Results showed that physical dispersion generated monomodal lognormal oil droplet size distributions of larger median diameters, whereas chemical dispersion produced bi- or trimodal lognormal oil droplet size distributions of smaller median diameters over a wider range. Factorial analysis of variance (ANOVA) followed by Tukey's paired comparison statistical data analysis indicated that the volume mean diameters of dispersed oil droplets were reduced by 36 μm (from 122 to 86 μm) by plunging breaking conditions. Volume mean diameters were decreased by 92 μm (from 153 to 61 μm) and 37 μm (from 153 to 116 μm), respectively, by Corexit 9500 and SPC 1000. These results are useful in optimizing operational guidelines for dispersant use, and providing input for modeling transport, fate, and biological effects of dispersed oil. [ABSTRACT FROM AUTHOR]

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 hydrodynamic conditions close to the mixing, transport, and dilution effects found in the natural environment. To this end, we have designed and constructed an experimental wave tank system capable of generating waves of different energy levels, ranging from regular nonbreaking waves to plunging breakers. The hydrodynamics of these wave conditions were characterized using an autocorrelation function method applied to in situ velocity measurements. We report here an investigation of the effectiveness of two chemical dispersants (Corexit 9500 and SPC 1000) on two crude oils (weathered MESA and fresh ANS) under three different wave conditions in the wave tank operated in batch mode. Corexit 9500 dispersed approximately 75% of the weathered MESA and more than 90% of the fresh ANS crude, and SPC 1000 dispersed about 53 and 64%, respectively. Under control conditions (absence of chemical dispersant), only 10 to 20% of the crude oils were dispersed. Quantitative relationships were established between dispersant effectiveness and energy dissipation rate under the different simulated wave conditions. These relationships are essential for the development of accurate predictive models on dispersant effectiveness and operational guidelines for dispersant use. [ABSTRACT FROM AUTHOR]

This paper describes recent advances in microscopic analysis for quantitative measurement of oil droplets. Integration of a microscope with bright-field and ultraviolet epi-fluorescence illumination (excitation wavelengths 340-380 nm; emission wavelengths 400-430 nm) fitted with a computer-controlled motorized stage, a high resolution digital camera, and new image-analysis software, enables automatic acquisition of multiple images and facilitates efficient counting and sizing of oil droplets. Laboratory experiments were conducted with this system to investigate the size distribution of chemically dispersed oil droplets and oil-mineral aggregates in baffled flasks that have been developed for testing chemical dispersant effectiveness. Image acquisition and data processing methods were developed to illustrate the size distribution of chemically dispersed oil droplets, as a function of energy dissipation rate in the baffled flasks, and the time-dependent change of the morphology and size distribution of oil-mineral aggregates. As a quantitative analytical tool, epi-fluorescence microscopy shows promise for application in research on oil spill response technologies, such as evaluating the effectiveness of chemical dispersant and characterizing the natural interaction between oil and mineral fines and other suspended particulate matters. [ABSTRACT FROM AUTHOR]

The evaluation of dispersant effectiveness used for oil spills is commonly done using tests conducted in laboratory flasks. We used a Hot Wire Anemometer (HWA) to characterize mixing dynamics in the Swirling Flask (SF) and the Baffled Flask (BF), the latter is being considered by the EPA to replace the prior to test dispersant effectiveness in the laboratory. Five rotation speeds of the orbital shaker carrying the flasks were considered, Ω = 50, 100, 150, 175 and 200 rpm. The radial and azimuthal water speeds were measured for each Ω. It was found that the flow in the SF is, in general, two-dimensional changing from horizontal at low Ω to axi-symmetric at high Ω. The flow in the BF appeared to be three-dimensional at all rotation speeds. This indicates that the BF is more suitable for representing the (inherently) 3-D flow at sea. In the SF, the speeds and energy dissipation rates ɛ increased gradually as the rotation speed increased. Those in the BF increased sharply at rotation speeds greater than 150 rpm. At 200 rpm, the Kolmogorov scale (i.e., size of smallest eddies) was about 250 and 50 μm in the SF and BF, respectively. Noting that the observed droplet sizes of dispersed oils range from 50 to 400 μm (hence most of it is less than 250 μm), one concludes that the mixing in the SF (even at 200 rpm) is not representative of the vigorous mixing occurring at sea. [ABSTRACT FROM AUTHOR]

A facile method for synthesis of environmentally friendly magnetite nanomaterials (MNMs) was applied using hydrophobic biocomponents as capping and stabilizing agents. The biocomponents were extracted from Matricaria aurea (MAE) and Ochradenus baccatus (OBE) and used for the surface modification of MNMs to increase their dispersion efficiency on the collection of heavy crude oil spills. Synthesized MNM samples (MAE-MNMs and OBE-MNMs) were verified using thermogravimetric analysis; Fourier-transform infrared spectroscopy; transmission electron microscopy; dynamic light scattering, and vibrating-sample magnetometry. The application of these nanomaterials in the collection of oil spill showed that the MAE-MNMs and OBE-MNMs successfully collected 95% and 91% of the oil spill, respectively. These results support the potential use of these materials as eco-friendly composites for the successful collection of oil spills that might occur during offshore operations. [ABSTRACT FROM AUTHOR]