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At present, the wide application of surfactants in various fields such as detergents, foam and emulsion stabilizers, fluorogens, hydrophobizers, corrosion inhibitors makes their synthesis considered one of the urgent issues. In the article, the results of the study of oil collecting and oil dispersing properties of the quaternary ammonium salt formed by triethanolamine (TEA) of heptanoic acid, which is a monobasic carbonic acid, in distilled, drinking, and seawater contaminated with Balakhani oil are given. The surface activity property of the products of different concentrations of this complex was calculated using a tensiometer, and the element content was calculated using the calculation method. The complex formed by heptanoic acid with TEA shows high surface activity by reducing the surface tension from 71.98 mN/m to 26.3 mN/m at that boundary. In the quaternary ammonium salt of heptanoic acid with TEA, the mass fraction of carbon is 55.9%, the mass fraction of hydrogen is 10.5%, the mass fraction of oxygen is 28.6%, and the mass fraction of nitrogen is 5%. The complex of heptanoic acid and TEA exhibits the ability to accumulate oil in seawater, both in the pure and 5% percent form of the reagent. Solutions of various concentrations of the complex formed by heptanoic acid with triethanolamine are well soluble in ethyl and isopropyl alcohols. [ABSTRACT FROM AUTHOR]

In the article, the results of the study of the quaternary ammonium salt formed by hexadecanoic acid, a monobasic carbonic acid, with monoethanolamine, in laboratory conditions, in distilled, drinking, and sea waters contaminated with Balakhani oil with different degrees of mineralization, are given. The surface activity property of the products of different concentrations of this complex was studied using a tensiometer, the element composition was calculated by calculation, and the composition and structure were confirmed by infrared spectroscopy. The result of investigating the composition of the complexes formed by hexadecanoic acid with monoethanolamine by infrared spectroscopy proves that the reaction proceeds according to the scheme indicated in the article. As a result of the research, it was determined that the mass share of carbon in the salt obtained on the basis of hexadecanoic acid and monoethanolamine is 68%, the share of hydrogen is 12.6%, the share of oxygen is 15%, and the share of nitrogen is 4.4%. The salt obtained on the basis of hexadecanoic acid and monoethanolamine shows high surface activity by reducing the surface tension at the water-air interface from 71.98 mN/m to 30.9 mN/m. The synthesized reagent has strong oil-collecting and oil-dispersing properties. With the application of this complex, it is possible to remove thin layers of oil from the water surface. The obtained complex is well soluble in ethyl and isopropyl alcohols. [ABSTRACT FROM AUTHOR]

BACKGROUND: Suspension concentrate (SC) is one of the most widely used formulations for agricultural plant protection. With the rapid development of unmanned aerial vehicle (UAV) plant protection, the problems of spray drift, droplet rebound and poor wettability in the application of SC from UAVs have attracted wide attention. Although some tank‐mix adjuvants have been used to enhance dosage delivery for UAV, their effects and mechanisms are not fully clear, and few formulations are specifically designed for UAV. RESULTS: The type and concentration of tank‐mix adjuvant affect the dosage delivery of SC. MO501 can significantly reduce DV<100μm, and inhibit droplet rebound on peanut leaves at concentrations ≥0.5%. Silwet 408 can achieve complete wetting and superspreading after adding ≥0.2% concentrations, but only ≥0.5% can inhibit rebound. XL‐70 shows excellent regulation ability even at low concentration, and 0.2% concentration can simultaneously suppress impact and promote spreading. Besides, the formulation oil dispersion (OD) can significantly reduce the driftable fine fraction and inhibit rebound at dilution ratios of ≤250‐fold, thus enhancing dosage delivery. CONCLUSION: SC is prone to rebound on hydrophobic leaf surfaces and shows poor wetting and spreading properties. Appropriate types and concentrations of tank‐mix adjuvants and formulation improvement are two effective strategies for improving the dosage delivery of pesticides, whereas the addition of inappropriate adjuvants may cause potential risks instead. These findings provide guidance for the rational selection of tank‐mix adjuvants and potential applications of OD for UAV plant protection. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

In the presented thesis, various physical indicators of quaternary ammonium salts formed by cis9-octadecene and octadecanoic acid with triethanolamine (TEA) were determined, and their structures were identified by IR spectroscopy. The surface-active property of this substance was checked by tensiometer using solutions of different concentration of the reagent at the water-air boundary. Also, the specific electrical conductivity of aqueous solutions of the obtained substance with different concentrations was studied using a conductometer. The oil-accumulating and oil-dispersing ability of the synthesized substance was studied on the surface of waters with different levels of mineralization, and the oil-accumulating and oil-dispersing abilities were studied. Oil accumulation and oil dispersing ability depends on oil layer thickness, water hardness, ions in water, oil density and hydrocarbon chain length, etc. the influence of factors has been studied. A comparative study of the properties of quaternary ammonium salts formed by cis 9-octadecene and octadecenoic acids with triethanolamine shows that the quaternary ammonium salt formed by octadecanoic acid with TEA shows greater surface activity properties than the quaternary ammonium salt formed by cis 9-octadecene with TEA, both salts are antimicrobial property, high electrical conductivity property, good oil collecting reagent property. [ABSTRACT FROM AUTHOR]

Oil–air lubrication has proven to be very effective for high-speed bearings because the oil supply in the form of droplets can be precisely controlled. This work uses optical interferometry to study the mechanism of lubricating film formation in rolling point contact with oil droplet lubrication. The effect of a double oil drop pair, where two oil droplets are positioned in mirror images about the central axis of the lubricated track, is examined. The process by which pairs of oil droplets approach and lubricate a bearing contact is analysed. This study also covers the effect of multiple oil droplets supplied in a tailored or a random dispersion pattern. Additionally, the effects of oil viscosity, entrainment velocity, and droplet distribution on starvation are also investigated. [ABSTRACT FROM AUTHOR]

Ionic liquid (IL) surfactants were prepared from 1-bromododecane and ethanolamines (2-dimethyl- and 2-diethylethanolamines) in an equimolar ratio to reveal how their oil-collecting and dispersing ability is influenced by the structure of the alkyl fragment. The surface activity of the substances synthesized was studied tensiometrically, and the electrical conductivity, conductometrically. The effect exerted on the colloid-chemical parameters of the surfactants by the replacement of the methyl fragment in the head group by the ethyl fragment is described. The relative oil-collecting and oil-dispersing ability of these substances was evaluated under laboratory conditions by the example of a thin oil film on the surface of waters with different levels of mineralization. [ABSTRACT FROM AUTHOR]

The unreasonable use of chemical pesticides has caused serious damage to crops and the ecological environment. The botanical pesticide matrine has attracted attention as an environmentally friendly pesticide. Compared with traditional spraying methods, unmanned aerial vehicle (UAV) spraying has the advantages of safety, rapidity, uniform droplets, low dosages, and no terrain or crop restrictions. In this study, matrine OD was prepared according to the application requirements of flight prevention preparations using three different emulsifiers. The stability, wettability, particle size and distribution, and spraying performance of matrine OD were studied. The results indicated that when the amount of emulsifier was 8%, the three types of matrine OD had good stability. The stability, wettability, particle size and distribution, and spray performance of the suspension prepared using emulsifier VO/03 were better than the other two emulsifiers. Therefore, matrine OD prepared using 8% VO/03 could be used for ultra-low-volume sprays and aerial applications. In this study, we provide a theoretical basis and technical guidance to develop pesticide formulations for aerial applications. [ABSTRACT FROM AUTHOR]

[Objectives] To determine the effectiveness of a dispersible oil suspension of Lecanicillium lecanni for the control of Aphis gossypii. [Methods] The toxicity of the suspension to A. gossypii was determined by the impregnation method and its effectiveness in a greenhouse by the five-point sampling method. The effect of temperature and humidity on its toxicity was determined by conducting trials under controlled temperature and humidity. [Results] Two dispersible oil suspensions of L. lecanni (1and 2) were found to be the most toxic after 120 h with LC50 values of 1.21 x 105 cfu/mL and 2.08 x 105 cfu/mL, respectively. There was a significant difference in the concentrations of the two formulations on the 14th day after application in the field. The best protection was provided by 4 x 106 cfu/mL and 2 x 106 cfu/mL of formulation 1, which had a lethality of 97.89% and 97.87%, respectively. There were also differences in the optimal temperatures for the two formulations. The optimal temperatures for Formulation 1were 25 °C and 28 °C, at which the adjusted mortality rates on the 5th day of 96.34% and 94.09%, respectively. The optimum temperature for Formulation 2 was 28 °C, at which the highest corrected mortality rate was 93.03%. There was no significant difference between the two formulations under the same relative humidity conditions; the optimum relative humidity was 67% of higher 5 days after treatment at which mortality was > 90%. Mortality for both treatments was around 70% at a relative humidity of about 30%. [Conclusion] Dispersible oil suspensions of L. lecanni are highly toxic to A. gossypii and ambient temperature and humidity have little effect on their toxicity to this pest. Such dispersible oil suspensions therefore appear to be a useful fungal insecticide for controlling A. gossypii populations. [ABSTRACT FROM AUTHOR]

Large amounts of waste cooking oil from residential areas can cause adverse effect on the environment if not disposed properly. Fungi have a higher tolerance to hydrocarbon toxicity due to their physiology and adaptation to the environment. Consequently, they can be employed in bioremediation to reduce waste oils release to the environment. This work aims to bio-remove and biodegrade the waste cooking oil using a newly isolated strain Aspergillus flavus USM-AR1, in stirred tank reactor (STR). The strain showed remarkable removal activity of waste cooking oil. The removal efficiency of waste cooking oil reached 97% on day 3 of cultivation. This was attained when the culture was agitated at 400 rpm, maintaining the Reynold's number of that obtained in the shake flask culture. Fortuitously, the best dispersion of waste cooking oil was also obtained at 400 rpm. The highest cell surface hydrophobicity (MATH) at 76.42% was observed at day 3 of cultivation. The maximum biosurfactant and emulsification activity occurred at day 2 of cultivation, which were 43 mm and 44%, respectively. Cell surface hydrophobicity and biosurfactant produced by strain Aspergillus flavus USM-AR1 played an important role in bio-removal of waste cooking oil, making this strain a prospective candidate for treating waste cooking oil. [ABSTRACT FROM AUTHOR]

Ships that transport oil or derivatives on the Lower Amazon River waterway are at a considerably high risk of suffering spills, with severe environmental and socioeconomic consequences. The present study is aimed at modeling and simulating the oil dispersion and magnitude of these accidents in terms of the vulnerability of biological resources, considering two oil types most often transported by medium-sized tankers in the region (S500 and S10). The study method was as follows: (a) secondary data were collected from local species, and the coastal sensitivity index (CSI) was calculated, obtained from Brazil's Letters of Environmental Sensitivity to Oil Spill (Cartas de Sensibilidade Ambiental ao Derramamento de Óleo (SAO)); (b) ship traffic information was obtained from Brazil's Statistical Yearbook of Waterway (Anuário Estatístico Aquaviário (ANTAQ)); (c) modeling and numerical simulation of oil spills in water were performed, in order to investigate dispersion scenarios (SisBaHia); (d) three numerical scenarios of oil plume dispersion (in May and November) were integrated to assess species vulnerability in three zones of environmental interest (I, II, and III). Some species identified in zone II were considered to be the most vulnerable (fish, plankton, aquatic mammals, amphibians, aquatic invertebrates, trees, and plants), with the mammal Sotalia fluviatilis being at risk of extinction (Gervais & Deville, 1853). The simulated scenarios showed that contingency plans should have a minimum response time of 3 h and a maximum response time of 72 h to prevent the oil plumes from dispersing as far as 170 km longitudinally, depending on the zone, season, and tidal phase. Thus, a total of 62 sites of biological resources were identified in the literature recorded from 2016. Considering them, 324 species of flora and fauna were recorded, distributed in the following seven groups: (i) 49 tree and plant species, (ii) 37 amphibian species, (iii) 2 aquatic invertebrate species, (iv) 23 invertebrate species, (v) 1 aquatic mammal species, (vi) 95 fish species, and (vii) 117 planktonic species. A failure to respond to these accidents would impact immense intact aquatic areas and ecosystems, with unpredictable consequences for local biodiversity conservation. [ABSTRACT FROM AUTHOR]

Oil–air lubrication has proven to be very effective for high-speed bearings because the oil supply in the form of droplets can be precisely controlled. This work uses optical interferometry to study the mechanism of lubricating film formation in rolling point contact with oil droplet lubrication. The effect of a double oil drop pair, where two oil droplets are positioned in mirror images about the central axis of the lubricated track, is examined. The process by which pairs of oil droplets approach and lubricate a bearing contact is analysed. This study also covers the effect of multiple oil droplets supplied in a tailored or a random dispersion pattern. Additionally, the effects of oil viscosity, entrainment velocity, and droplet distribution on starvation are also investigated.

In some applications, including the interaction of surfactants with petroleum products, the use of magnetic surfactants is a good idea for collecting the oil leaked from ships on seawater; however, the high use of these materials in various industries has resulted in environmental pollution. In this paper, first, by adding Iron (III) chloride hexahydrate (FeCl3(H2O)6), Nickel(II) chloride hexahydrate (NiCl2(H2O)6), Cobalt (II) chloride hexahydrate (CoCl2(H2O)6), surfactants of magnetic cetyltrimethylammonium bromide and dodecyltrimethylammonium bromide were prepared. Then, for the first time, with the help of these salts, the natural surfactant extracted from the Licorice roots has been magnetized as an environmentally friendly surfactant. Next, the surface properties of these materials were examined and the performances of magnetic and non-magnetic samples were compared. Ultimately, a mixture of synthetic and natural magnetic surfactants was used to disperse the oil, and the emulsion produced was collected by the magnet, and its performance was compared with the mixture of natural and synthetic non-magnetic surfactants. [ABSTRACT FROM AUTHOR]

The unreasonable use of chemical pesticides has caused serious damage to crops and the ecological environment. The botanical pesticide matrine has attracted attention as an environmentally friendly pesticide. Compared with traditional spraying methods, unmanned aerial vehicle (UAV) spraying has the advantages of safety, rapidity, uniform droplets, low dosages, and no terrain or crop restrictions. In this study, matrine OD was prepared according to the application requirements of flight prevention preparations using three different emulsifiers. The stability, wettability, particle size and distribution, and spraying performance of matrine OD were studied. The results indicated that when the amount of emulsifier was 8%, the three types of matrine OD had good stability. The stability, wettability, particle size and distribution, and spray performance of the suspension prepared using emulsifier VO/03 were better than the other two emulsifiers. Therefore, matrine OD prepared using 8% VO/03 could be used for ultra-low-volume sprays and aerial applications. In this study, we provide a theoretical basis and technical guidance to develop pesticide formulations for aerial applications.

Aiming the production of lipopeptides biosurfactants (BioS), we isolated a new strain identified as Bacillus subtilis ZNI5 from a hydrocarbon contaminated soil. Lipopeptides purification by anionic exchange chromatography and identification by Reverse Phase High Performance Liquid Chromatography–Mass Spectrometry (RP-HPLC–MS) permitted the selection of different homologues divided into four families. The first family corresponds to Surfactin isoforms with molecular weights of 1007, 1021 and 1035 Da; the second family correspond to Iturin isoforms with molecular weights of 1028, 1042 and 1056 Da; the third family correspond to a single isoform called Licheniformin with molecular weight of 1410 and the fourth family correspond to newly identified isoforms named Inesfactin with molecular weights of 973 and 987 Da. Regarding the functional properties of the ZNI5 BioS, it was characterized as a powerful surface-active agent that decreases the Surface Tension of water from 72 mN/m to about 32 mN/m with a CMC value of 350 mg/L more efficient than chemical surfactants (Triton X100; CTAB and SDS). Moreover, it has the capacity to disperse oil to about 80 mm at a concentration of 800 mg/L showing close efficiencies to the listed chemical surfactants. In addition, the physic–chemical characterization of the surface activities of ZNI5 BioS showed great thermal, pH and salts activity and stability enabling its use in the bioremediation fields and for diverse industrial applications. [ABSTRACT FROM AUTHOR]

Oil dispersion, a crucial process in oil transport, involves the detachment of oil droplets from slicks and their introduction into the water column, influencing subsequent oil migration and transformation. This study examines oil dispersion, considering characteristics, stability, and mechanisms, while evaluating the impact of dispersants and salinity. Results show the significant role of surfactant type in dispersants on oil dispersion characteristics, with anionic surfactants exhibiting higher sensitivity to salinity changes compared to nonionic surfactants. The dispersion efficiency varies with salinity, with anionic surfactants performing better in low salinity (<20‰) and nonionic surfactants showing superior performance at 30–35‰ salinities. Rheological analysis illustrates the breakup and coalescence of oil droplets within the shear rates of breaking waves. An increase in interfacial film rigidity impedes the coalescence of oil droplets, contributing to the dynamic stability of the oil-water hybrid system. The use of GM-2, a nonionic dispersant, results in the formation of a solid-like interface, characterized by increased elastic modulus, notably at 20‰ salinity. However, stable droplet size distribution (DSD) at 35‰ salinity for 60 h suggests droplets can remain dispersed in seawater. The enhancement of stability of oil dispersion is interpreted as the result of two mechanisms: stabilizing DSD and developing the strength of viscoelastic interfacial film. These findings offer insights into oil dispersion dynamics, highlighting the importance of surfactant selection and salinity in governing dispersion behavior, and elucidating mechanisms underlying dispersion stability. [Display omitted] • The combined effects of dispersant and salinity on oil dispersion are assessed. • Surfactant types dictate in a large part the droplet size distribution of oil. • Anionic surfactants are more sensitive to the salinity of aquatic environment. • An increase in interfacial film rigidity impedes coalescence of oil droplets. • The salinity of 35‰ is favorable for the stability of oil dispersion. [ABSTRACT FROM AUTHOR]

Over the latest decades, oil marine pollution has posed a vital threat for global ocean health, since spillages of any scale are related to environmental, social and financial impacts. The worldwide increase in oil and gas demand, and the parallel rise in oil and gas production, exploiting particularly coastal and offshore marine deposits, have significantly increased the risk of accidental oil release to the sea. In the present study, an operational oil spill model was applied to test the oil dispersive properties and to reveal the relative magnitude of weathering processes, after an accidental oil spill release along the main tanker transportation route in the North Aegean Sea. Numerical simulations were implemented using the OpenOil transport and fate numerical model, a subclass of the OpenDrift open-source trajectory framework. This model integrates algorithms with several physical processes, such as oil entrainment, vertical mixing, oil resurfacing and oil emulsification. The oil dispersion model was coupled to real-time met-ocean forecasts received from NOAA-GFS and CMEMS. Present simulation results have focused on the impact of turbulent kinetic energy, induced by the background flow field, on the horizontal spreading of particles, as well as on the evolution of oil mass balance and oil mass properties. [ABSTRACT FROM AUTHOR]

As a reflective display technology, electrowetting displays (EWDs) have the advantages of paper-like display, low power consumption, fast response, and full color, but the aperture ratio of EWDs is seriously affected by oil dispersion and charge trapping. In order to improve the aperture ratio and optimize the display performance of EWDs, a combined pulse driving waveform with rising gradient design was proposed. First, an initial driving voltage was established by the threshold voltage of oil film rupture (Vth). And then, a rising gradient was designed to prevent oil from dispersing. At last, the oil splitting and movement were controlled to achieve the target aperture combined with the pulse waveform. Experimental results showed that the oil dispersion of EWDs can be effectively improved by using the proposed driving waveform, the aperture ratio of EWDs was increased by 3.16%, and the stability was increased by 71.43%.

The dispersion of oil droplets in rivers was numerically investigated for uniform flow in a hypothetical wide river with a depth of 3.0 m. The river hydrodynamics profile was used in conjunction with the VDROP model to produce the oil droplet size distribution (DSD), whereas the NEMO3D model was used to track the movement of the oil droplets. Results suggest that the gradient of eddy diffusivity significantly affected the upward-normal (i.e., quasi-vertical) transport of the droplets, and caused them to mix rapidly through the depth. We also found that an increase in buoyancy resulted in a decrease in the streamwise variance and spreading coefficient. Oil droplets broke up due to the relatively large energy dissipation rates in the river at approximately 1.0 m below the surface and deeper. The droplet breakup varies DSD in the river water column, which may subsequently affect other chemo-physical processes (e.g., oil-particle aggregation). The breakup efficiency is affected by a system-dependent parameter Kb , which reflects the uncertainty of a system. The steady-state DSD was bimodal for the case Kb=0.05 , whereas it was unimodal for larger Kb values (i.e., Kb=1.0 and 0.25), respectively. More small-sized droplets were generated and persisted in the deep-water column with larger Kb values. The droplet breakup also enhanced the streamwise spreading of the plume. The effect of droplet entrainment on oil dispersion was studied by assuming constant entrainment probabilities of surface oil droplets. The oil DSD varied with different droplet entrainment probabilities, and the number of oil droplets generated in the water column decreased significantly with a decrease in the entrainment probability of the oil droplets. [ABSTRACT FROM AUTHOR]

Over the latest decades, oil marine pollution has posed a vital threat for global ocean health, since spillages of any scale are related to environmental, social and financial impacts. The worldwide increase in oil and gas demand, and the parallel rise in oil and gas production, exploiting particularly coastal and offshore marine deposits, have significantly increased the risk of accidental oil release to the sea. In the present study, an operational oil spill model was applied to test the oil dispersive properties and to reveal the relative magnitude of weathering processes, after an accidental oil spill release along the main tanker transportation route in the North Aegean Sea. Numerical simulations were implemented using the OpenOil transport and fate numerical model, a subclass of the OpenDrift open-source trajectory framework. This model integrates algorithms with several physical processes, such as oil entrainment, vertical mixing, oil resurfacing and oil emulsification. The oil dispersion model was coupled to real-time met-ocean forecasts received from NOAA-GFS and CMEMS. Present simulation results have focused on the impact of turbulent kinetic energy, induced by the background flow field, on the horizontal spreading of particles, as well as on the evolution of oil mass balance and oil mass properties.

Oil dispersion under a deep-water plunging breaker of height 0.15 m was studied by coupling the Lagrangian particle tracking code (NEMO3D) with the population balance model (VDROP). The wave hydrodynamics obtained in Part I (Cui et al. in Environ Fluid Mech 2020 (in press)) was used as input. It was observed that droplet inertia and major forces on droplets significantly impacted the transport of oil droplets under wave conditions, and neglecting it caused less entrainment into the water column and horizontal spread of oil plume. For droplets less than 400 microns, the droplet size distribution (DSD) tended to follow a power-law distribution with an exponent close to − 2.3, which was consistent with earlier experimental observations by Delvigne and Sweeney (Oil Chem Pollut 4(4):281–310, 1988). The distribution of large size droplets evolved with time and showed agreement with a power-law distribution having an exponent of − 9.7 about 20 s after the passage of the wave train. Reducing the interfacial tension enhanced droplets breakup and increased the exponent of power-law distribution to − 6.1 for droplets smaller than 400 microns. It was also found that neglecting the vertical gradient of eddy diffusivity led to the accumulation of oil droplets in low eddy diffusivity regions at the bottom part of the wave breaker. The investigation herein could be used to obtain design values for breakers that could be used in oil spill models to predict the oil droplet size distribution. [ABSTRACT FROM AUTHOR]

In order to clarify the effect of different thickeners on the stability of oil suspension system with mineral oil as dispersion medium, 12.5% oxadiargyl + pyrazosulfuron-ethyl oil dispersion was used as the research object. The effects of three types of thickeners (including organic bentonite, organic polymer and gaseous silica) and organic bentonite used with other two types of thickeners on the physical stabilities of oil dispersions were studied by rheology and multiple light scattering methods. The results showed that the flow characteristic index (n) of all samples were less than 1, which was a pseudoplastic fluid with thixotropic properties. Except the combination of organic bentonite and organic polymer Atlox Rheostrux 100, the system was more in line with the Casson equation. While other samples were more in line with the Herschel-Bulkley equation. Organic bentonite has a relatively good performance to increase the stability of the system when used alone. Two kinds of organic polymer thickeners, including Atlox Rheostrux 100 and Atlox Rheostrux 200, had different performance. Atlox Rheostrux 100 had more significsant effect than that of Atlox Rheostrux 200, which might result from their different molecular structures. Two gaseous silica thickeners exhibited little effect, because they can’t form hydrogen bonds effectively. When organic bentonite used with other two types of thickeners, organic bentonite and organic polymer combination can improve the performance. Particularly, organic bentonite 869 and Atlox Rheostrux 100 combination was better than others, wich suspension system had high viscosity and good thixotropy, and excellent physical stability. However, organic bentonite 869 and hydrophobic silica R974 combination had no improvement. The results showed that both rheological and multiple light scattering can characterize the physical stability of the oil dispersion, and the novel orgainc polymer thickener and organic bentonite have synergistic effect, combination reasonable can greatly improve the stability of the oil dispersion. [ABSTRACT FROM AUTHOR]

Abstract Biosurfactants possess diverse chemical properties and provide important characteristics to the producing microorganisms, which can act as surface-actives and emulsifiers of hydrocarbon and others water insoluble substances. Most of them are lipopeptides synthetized by Bacillus. This study evaluated the biosurfactant production by strains of Bacillus previously obtained from liquid residues of sugar-alcohol industry. The bacterial isolates LBPMA: BSC, BSD, J1, J2 and L1 were cultivated in medium that induces production of biosurfactants (Landy medium). During 48 h of incubation, at intervals of 12 h, the total contents of proteins, reducing carbohydrates and surfactant activity of the filtrated growth media free of cells were evaluated. The results showed that these strains use glucose as a source of carbon, energy and for synthesis of surfactant. In this medium (24 h), the best producer of biosurfactant was the strain LBPMA-J2, molecularly identified as Bacillus thuringiensis. Once the supernatant free of cells of this microorganism disperses the oil phase in the water, this strain has potential for being utilized on bioremediation processes.

One simple, efficient, reliable, and inexpensive method to protect the inner surface of slim tubes prior to exposure to corrosion is to apply a dispersed oil fraction through a nozzle and a mixing valve to prepare a mixture of air and oil applied on the texture in a suitable form. The problem, in particular, is in transporting the oil micro particles to the distal end of the lean tube. The method also has an ecological effect, since other known "soaking" methods of oil application onto the inner surface of slim tubes require long and laborious cleaning methods with higher oil consumption. This method was experimentally verified by measurement and modal simulation in Ansys CFX 19.1 software. The results indicate the possibilities of using the method in practice. However, there are a few rules and recommendations to follow when applying this solution strategy. [ABSTRACT FROM AUTHOR]

The formulation of mycopesticides may require a physical separation of conidia from the substrate and subsequent drying. In the present study, Beauveria bassiana conidia produced by solid-state fermentation were harvested either through a dry or washing protocol. Washed conidia were used to design a water-dispersible granule (WG) formulation, whereas sieved conidia were mixed with an emulsifiable oil to achieve an oil-based formulation (OD). Potential harmful effects caused by the formulation type on the storage stability and insecticidal activity against Hypothenemus hampei were assessed. As expected, the time for initial conidial germination to drop 50% (GT50) in all treatments was deeply influenced by storage temperatures, which varied from over 180 days at 4 °C to less than 90 days at 35°C. In all four tested temperatures, GT50s for unformulated dry conidia were significantly higher than for those formulated as WG, and the latter was similar to conidia formulated as OD in the two highest temperatures. Residual water content in the OD formulation (1,600 vs. 340 ppm) had a negative influence on conidial survival under storage, whereas WG granules immediately dried after the washing protocol showed conidial germination similar to granules exposed to a slower dehydration regime. Mortality of H. hampei adults exposed to different concentrations of B. bassiana formulated as WG was slightly lower (10-15%) than either the OD or the unformulated conidia. In brief, we have demonstrated that formulation type and their moisture level can affect the storage stability and insecticidal activity of B. bassiana conidia toward the coffee berry borer. Of particular importance, we have shown that drying oils prior to formulation could improve the storage of mycopesticides, an approach that may find industrial applications. [ABSTRACT FROM AUTHOR]

Group and elemental compositions and structures of hydrocarbon dispersions in super-viscous oil resulting from steam and heat exposure at 140-190°C and 3-6 atm in the presence of hexane and benzene are established using simplified models of terrigenous and carbonate reservoirs. A relationship between the composition and structure of the oil dispersions after steam-heat action and a temperature dependence of viscosity are established. Solvate shells of increased thickness around complex structural unit nuclei and a greater proportion of dispersion medium are distinctive features of the low-viscosity displaced oil. Studies show that the dispersion medium impacts greatly the formation and properties of the oil dispersion. Benzene in the displacing agent decreases the degree of dispersion of the system and the viscosity of the displaced oil. [ABSTRACT FROM AUTHOR]

The primary objective of the Consortium for the Molecular Engineering of Dispersant Systems (C-MEDS) was to understand the molecular basis of dispersant systems, the way the components of dispersants act in breaking oil into small drops by studying in detail the processes at the interface of oil and water. As a consequence of such improved understanding, it was also an objective to design alternative concepts in oil dispersion, taking into account natural processes occurring in ocean environments. The development of new environmentally benign dispersants was always an underlying focus of research efforts. [ABSTRACT FROM AUTHOR]

We introduce a model for the dynamics of oil in suspension, appropriate for shallow waters, including the nearshore environment. This model is capable of oil mass conservation and does so by evolving the oil on the sea surface as well as the oil in the subsurface. The shallower portion of the continental shelf poses compounding unique modeling challenges. Many of these relate to the complex nature of advection and dispersion of oil in an environment in which wind, waves, as well as currents all play a role, as does the complex bathymetry and the nearshore geography. In this study we present an overview of the model as well as derive the most fundamental of processes, namely, the shallow water advectiion and dispersion processes. With regard to this basic transport, we superate several fundamental challenges associated with creating a transport model for oil and other buoyant pollutants, capable of capturing the dynamics at the large spatio-temporal scales demanded by environmental and hazard mitigation studies. Some of the strategies are related to dimension reduction and upscaling, and leave discussion of these to companion papers. Here we focus on wave-filtering, ensemble and depth-averaging. Integral to the model is the proposal of an ocean dynamics model that is consistent with the transport. This ocean dynamics model is detailed here. The ocean/oil transport model is applied to a couple of physically-inspired oil-spill problems in demonstrate its specialized capabilities.

Knowledge of the droplet size distribution (DSD) of spilled oil is essential for the accurate prediction of oil transport, dissolution, and biodegradation. Breaking waves play important roles in oil droplet formation in oceanic environments. To understand the effects of breaking waves on oil DSD, oil spill experiments were designed and performed in a large-scale wave tank. A plunging breaker with a height of about 0.4 m was produced using the dispersive focusing method within the tank. Oil placed within the breaker resulted in a DSD that was measured using a shadowgraph camera and found to fit a Gaussian distribution (µ = 1.2 mm, σ2 = 0.29 mm2). For droplets smaller than 1500 µm, the number-based DSD matched the DS1988 correlation [1], which gives N(d) ~ d-2.3, but this was N(d) ~ d-9.7 for droplets larger than 1500 µm. An order of magnitude investigation revealed that a Gaussian volume-based DSD results in a number-based DSD that may be approximated by d-b (with b ≈ 2) for small diameters (relative to the mean), which explains the occurrence of the DS1988 correlation. With the measured wave hydrodynamics, the VDROP model was adopted to simulate the DSD, which closely matched the observed DSD. The present results reduce the empiricism of the DS1988 correlation.

This study evaluated the applicability of eight types of biomarkers namely, adamantanes, diamantanes, sesquiterpanes, steranes, terpanes, TA-steranes, MA-steranes, and alkylated PAHs, to characterize chemically dispersed oil (CDO) after the 60-day weathering. The stability of diagnostic ratios of the selected biomarkers was evaluated and summarized. The results indicated that the concentrations of biomarkers with low molecular weight, such as adamantanes, diamantanes, and sesquiterpanes, in CDO were markedly affected by weathering and the associated diagnostic ratios were changed extensively. Most of the alkylated PAHs were degraded during weathering as well. These biomarkers thus were not recommended for characterizing CDO. The majority of the terpanes, steranes, TA-steranes, and MA-steranes could be used for weathered CDO fingerprinting due to the relatively stable diagnostic ratios. The findings could help to identify applicable biomarkers for fingerprinting of weathered dispersed oil. [ABSTRACT FROM AUTHOR]

To evaluate the degree and rate of absorption of orally administered dose of Ca, Mg and Fe in oil and water dispersion mineral prescriptions in comparison with mineral raw material mixing powder, plasma and liver Ca, Mg and Fe concentrations and pharmacokinetic profiles of plasma and liver Ca, Mg and Fe concentration-time were observed after administration of oil and water dispersion mineral prescriptions and mineral raw material powder. Ca, Mg and Fe contents in plasms and liver homogenate were measured by using inductively coupled plasma mass spectrometry (ICP-MS). The time course of plasma Ca concentrations indicates that AUC and Cmax of plasma Ca following oil dispersion prescription could be the most great compared with water dispersion prescription and raw material mixing powder, suggesting that Ca in oil dispersion prescription is more bioavailable from gastrointestinal tract than that in water dispersion prescription and raw material mixing powder and absorption rate of Ca in Oil dispersion prescription is more rapid than that in Water dispersion prescription and Raw material mixing powder. The time to reach peak of plasma Mg after administration of Oil dispersion prescription is less than that after administration of Water Dispersion prescription and Raw Material Mixing Powder suggesting that absorption rate of Mg in Oil dispersion prescription may be more rapid compared with other two prescriptions. The liver Ca, Mg and Fe levels in early time period following administration of these three prescriptions increase rapidly, and then decrease, suggesting that Ca, Mg and Fe absorbed in these three prescriptions are contributed to liver tissue at the beginning and then rc-contributed in body. [ABSTRACT FROM AUTHOR]

One simple, efficient, reliable, and inexpensive method to protect the inner surface of slim tubes prior to exposure to corrosion is to apply a dispersed oil fraction through a nozzle and a mixing valve to prepare a mixture of air and oil applied on the texture in a suitable form. The problem, in particular, is in transporting the oil micro particles to the distal end of the lean tube. The method also has an ecological effect, since other known “soaking” methods of oil application onto the inner surface of slim tubes require long and laborious cleaning methods with higher oil consumption. This method was experimentally verified by measurement and modal simulation in Ansys CFX 19.1 software. The results indicate the possibilities of using the method in practice. However, there are a few rules and recommendations to follow when applying this solution strategy.

Crude oil that is inadvertently spilled in the marine environment can interact with suspended sediment to form oil-mineral aggregates (OMA). Researchers have identified OMA formation as a natural method of oil dispersion, and have sought ways to enhance this process for oil spill remediation. Currently there is a lack of understanding of how the weathering of oil will affect the formation of OMA due to a lack of published data on this relationship. Based on literature, we identified two conflicting hypotheses: OMA formation 1) increases with weathering as a result of increased asphaltene and polar compound content; or 2) decreases with weathering as a result of increased viscosity. While it is indeed true that the viscosity and the relative amount of polar compounds will increase with weathering, their net effects on OMA formation is unclear. Controlled laboratory experiments were carried out to systematically test these two conflicting hypotheses. Experimental results using light, intermediate, and heavy crude oils, each at five weathering stages, show a decrease in OMA formation as oil weathers. [ABSTRACT FROM AUTHOR]

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 (4.1–5.6 mg 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 (0.08 mg 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. [ABSTRACT FROM AUTHOR]

Biosurfactant production optimization by Candida tropicalis UCP0996 was studied combining central composite rotational design (CCRD) and response surface methodology (RSM). The factors selected for optimization of the culture conditions were sugarcane molasses, corn steep liquor, waste frying oil concentrations and inoculum size. The response variables were surface tension and biosurfactant yield. All factors studied were important within the ranges investigated. The two empirical forecast models developed through RSM were found to be adequate for describing biosurfactant production with regard to surface tension (R² = 0.99833) and biosurfactant yield (R² = 0.98927) and a very strong, negative, linear correlation was found between the two response variables studied (r = -0.95). The maximum reduction in surface tension and the highest biosurfactant yield were 29.98 mNm-1 and 4.19 gL-1, respectively, which were simultaneously obtained under the optimum conditions of 2.5% waste frying oil, 2.5%, corn steep liquor, 2.5% molasses, and 2% inoculum size. To validate the efficiency of the statistically optimized variables, biosurfactant production was also carried out in 2 and 50 L bioreactors, with yields of 5.87 and 7.36 gL-1, respectively. Finally, the biosurfactant was applied in motor oil dispersion, reaching up to 75% dispersion. Results demonstrated that the CCRD was suitable for identifying the optimumproduction conditions and that the new biosurfactant is a promising dispersant for application in the oil industry. [ABSTRACT FROM AUTHOR]

ELUMIS® is a new liquid maize herbicide containing mesotrione for control of annual millets and dicotyledonous weeds and nicosulfuron for control of grasses. Field testing on efficacy and crop tolerance of ELUMIS in maize was conducted in Europe in the maritime, south-eastern and north-eastern EPPO climate zone from 2007 to 2010. Essential innovation as compared to common tankmixtures of the sole ingredients of ELUMIS is the formulation technology for easy handling: The oil dispersion is the first formulation combining a triketone and a sulfonylurea. Uptake studies using 14C-labelled active ingredients revealed for both mesotrione and nicosulfuron a faster foliar uptake from the ELUMIS formulation than from single a. i. formulations or a tankmixture. 1.5 l/ha ELUMIS applied from early to late post-emergence control a broad spectrum of broadleaved weeds and grasses including perennials such as Lolium perenne and Agropyron repens. Comparative tests on various maize varieties revealed good crop tolerance in nearly all maize hybrids currently grown in Central Europe. In Central Europe on loamy soils with a pH above 6 the potential for a rotational crop injury is neglible for all main crops sensitive to mesotrione. ELUMIS primarily offers foliar activity; if required it can be combined with residual partners such as S-metolachlor (in DUAL® GOLD or GARDO® GOLD) or terbuthylazine (also in GARDO® GOLD) to achieve apart from foliar also a satisfactory duration of activity on those grasses and dicotyledonous weeds germinating after application. Apart from this, tankmixtures of ELUMIS and other herbicides for broadleaved weed control enhance the reliability of efficacy on difficult to control species, e. g. Polygonum aviculare.

Abamectin was developed as an insecticide, nematocide and acaricide for use on a varietyof agricultural and horticultural crops. The products with this active ingredient can befound on the market mostly formulated as emulsifiable concentrate (EC). Usually producersrecommend using the EC formulation of abamectin together with some kind of adjuvants(natural oils) to improve efficacy of the active ingredient. To overcome the efficacy problemwe tried to formulate the active ingredient abamectin as oil dispersion (OD). Oil dispersion,preferably based on naturally derived oils could improve pesticide efficacy. This type of pesticideformulation contains oil instead of water as in classical suspension concentrate andtypically has better retention and coverage. In the case of abamectin, in this investigationsoybean oil was used with the mixture of different nonionic emulsifiers. Content of abamecetinin formulation was 1.8 %. The developed formulation was tested for few importantparameters. The obtained physicochemical properties for the above mentioned formulationhave shown that it is stable and could be used in plant protection.

Adsorption of suspended particles to the interface of surfactant-dispersed oil droplets can alter emulsion phase and sedimentation behavior. This work examines the effects of model mineral aggregates (silica nanoparticle aggregates or SNAs) on the behavior of oil (octane)–water emulsions prepared using sodium bis(2-ethylhexyl) sulfosuccinate (DOSS). Experiments were conducted at different SNA hydrophobicities in deionized and synthetic seawater (SSW), and at 0.5 mM and 2.5 mM DOSS. SNAs were characterized by thermogravimetric analysis (TGA) and dynamic light scattering (DLS), and the emulsions were examined by optical and cryogenic scanning electron microscopy. In deionized water, oil-in-water emulsions were formed with DOSS and the SNAs did not adhere to the droplets or alter emulsion behavior. In SSW, water-in-oil emulsions were formed with DOSS and SNA–DOSS binding through cation bridging led to phase inversion to oil-in-water emulsions. Droplet oil-mineral aggregates (OMAs) were observed for hydrophilic SNAs, while hydrophobic SNAs yielded quickly sedimenting agglomerated OMAs. [ABSTRACT FROM AUTHOR]

In African cacao-producing countries, control of cacao black pod disease caused by Phytophthora megakarya is a priority. Introducing biological control agents as part of a P. megakarya control strategy is highly desirable, especially in a perspective of pesticide reduction. Trichoderma species are among the most used biological control agents. In Cameroon, Trichodermaasperellum formulated in wettable powder has produced positive effects against this disease. However, with this type of formulation, shelf-life and persistence of conidia on pods are limited. Our study therefore sought to develop a new T. asperellum formulation that would be more effective and better suited to the conditions of field application by small-scale producers in Cameroon. We selected a soybean oil-based oil dispersion, in which the half-life of the conidia reached 22.5 weeks, versus 5 weeks in aqueous suspension. Tested on detached pods, the formulation completely inhibited the development of the disease. When sprayed in the field on cacao clones highly sensitive to P. megakarya, the formulation resulted in 90% protection of treated pods after 1 week, and 50% after 3.2 weeks. The formulations exercised a measurable effect for up to 7 weeks, versus 2 weeks in the case of an aqueous conidial suspension and 5 weeks for that of a conventional fungicide (Kocide). Trichodermaasperellum formulated in oil dispersion has therefore great potential for the control of cacao black pod disease with less recourse to synthetic fungicides. Moreover, this formulation is well adapted to the types of sprayers used by small-scale cacao producers in Cameroon. [ABSTRACT FROM AUTHOR]

Combating the pollution with hydrocarbons includes preventive methods but also intervention methods. In present worldwide, are used five methods to combat the pollution with hydrocarbons. Using either of these methods involve a number of factors such as: weather limit conditions, technical features of intervention equipment, boundary conditions on the state of the pollutant and a number of advantages and disadvantages depending on the type of method chosen. [ABSTRACT FROM AUTHOR]

Abstract: Oil–suspended particulate matter aggregation (OSA) has been recognized by the oil spill remediation community to effectively enhance the cleansing of spilled oil in the marine environment. While studies have investigated the application of mineral fines as an effective method to facilitate oil dispersion, decision-makers still lack information on the role of mixing energy in OSA formation and its significance to oil dispersion in real spills. This work studied the effect of level and duration of mixing energy on OSA formation using the standard reference material 1941b and Arabian light crude oil. The results showed that dispersed small oil droplets increased with an increase of both the level and duration of mixing energy to form multi-droplet OSAs. The sizes of the dispersed droplets varied between 5 and 10μm under different conditions studied. The maximum oil trapping efficiency increased from 23% to 33%, the oil to sediment ratio increased from 0.30 to 0.43goil/g sediment, and the required shaking time decreased from 2.3 to 1.1h as the shaking rate increased from 2.0 to 2.3Hz. Based on the size measurement results, a breakage effect on the formed OSAs and sediment flocs was confirmed under high mixing energy level. [Copyright &y& Elsevier]

Highlights: [•] OSA formation reaches equilibrium (24–47% of E max) within 5h after the spill. [•] The oil-to-sediment ratio reaches 0.24–0.68 within 5h following the oil spill. [•] Solid and single-droplet OSAs are dominant under low mixing energy. [•] Increase of sediment concentration and mixing energy enhances OSA formation. [•] The OSA size increased with the shaking time. [Copyright &y& Elsevier]

Abstract: The present study investigated the impact of subchronic exposure of the water accommodated fraction (WAF) of light Arabian crude oil, dispersed oil and dispersant on the gills of the juvenile brown spotted grouper (Epinephelus chlorostigma), observing several histopathological lesions at different time points and different concentrations. Significant alterations, compared to the control groups (p < 0.05), in four health categories (circulatory, proliferative, degenerative and inflammatory) were identified. Evaluations of histopathological lesions in gill tissue were carried out following 3, 6, 9, 12, 15, 18 and 21 days of exposure. The main lesions observed were circulatory (lamellar aneurysms, vasodilatation and hemorrhage), degenerative (edema, lifting of lamellar and filamentary epithelium and epithelium necrosis), proliferative (hypertrophy and hyperplasia of epithelial, mucous and chloride cells, fusion of adjacent lamellae), and inflammatory (lymphocytic infiltration). These results provide a tool for evaluating reclamation initiatives, such as the use of dispersants, and lead to better risk evaluations and environmental health in natural and reclaimed systems. [Copyright &y& Elsevier]

The application of modified-bentonite-enhanced oil dispersion in water and oil-mineral aggregate (OMA) formation was studied in the laboratory. The effect of modification on the surface properties of bentonite was characterized. The hydrophobicity and surface electric properties of bentonite were significantly improved by attaching cetyltrimethyl ammonium bromide to its surface. The results showed that surface properties of bentonite played an important role in OMA formation. Spherical droplets of OMAs were formed with natural bentonite and elongated solid OMAs and flake OMAs were formed with modified bentonite as observed by fluorescence microscopy. The effects of shaking time, oil concentration and mineral content were also studied. It was suggested that oil concentration and mineral content were critical factors and OMA formed rapidly with both types of bentonite. Modified bentonite had better performance on OMA formation than hydrophilic natural bentonite. [ABSTRACT FROM AUTHOR]

Abstract: We evaluated the potential contribution of oil droplets to the toxicity of dispersed oil to first feeding fish larvae. Atlantic cod larvae were exposed to five concentrations of either artificially weathered (200°C residue) dispersed oil (D1–D5) containing oil droplets [medium size 11–13μm based on volume] and water-soluble fraction [WSF] or the filtered dispersions containing only the corresponding equilibrium WSFs only (W1–W5). The larvae were exposed for 4days and harvested for transcriptional analysis at 13days post hatching. The most significant differently expressed genes were observed in cod larvae exposed to the highest concentration of the dispersed oil (containing 10.41±0.46μg ∑PAH/L), with CYP1A showing the strongest response. Functional analysis further showed that the top scored network as analyzed with Ingenuity Pathway Analysis was “Drug Metabolism, Endocrine System Development and Function, Lipid Metabolism”. Oil exposure also increased the expression of genes involved in bone resorption and decreased the expression of genes related to bone formation. In conclusion, oil exposure affects drug metabolism, endocrine regulation, cell differentiation and proliferation, apoptosis, fatty acid biosynthesis and tissue development in Atlantic cod larvae. The altered gene transcription was dominated by the WSF and the corresponding oil droplet fraction only had a moderate contribution to the observed changes. [Copyright &y& Elsevier]

Abstract: The formation of oil-suspended particulate matter aggregates (OSAs) results from the heteroaggregation between dispersed oil droplets and suspended particulate matter present in coastal waters. This process has been recognized by the oil spill remediation community to enhance natural cleansing of oiled shorelines and oil dispersion in the water column. While several studies have been conducted on the formation and characteristics of OSAs, few studies have addressed the kinetics of OSA formation. Operationally, this has left decision-makers lacking information on the time scale of this process and its significance to oil dispersion in real spills. A laboratory study was conducted to investigate the kinetics of OSA formation as a function of mixing energy and the sediment-to-oil ratio using the standard reference material 1941b. Results showed that formation of OSAs increased exponentially with the mixing time and reached a maximum within 4h. When the shaking rate increased from 2.0 to 2.3Hz, the maximum oil trapping efficiency increased from 20% to 42% and the required shaking time decreased from 3.7 to 0.7h. [ABSTRACT FROM AUTHOR]

Abstract: Polycyclic aromatic hydrocarbons (PAHs) and other oil compounds are known to induce stress and impact health of marine organisms. Water-soluble fractions of oil contain components known to induce glutathione S-transferases (GSTs), one of the major classes of phase II detoxifying enzymes present in essentially all eukaryotic organisms. In this study, the transcriptional responses of six GSTs (GST pi, GST mu, GST omega, GST theta, GSY zeta and GST kappa) were examined in early larvae of Atlantic cod Gadus morhua exposed to five concentrations of dispersed oil (containing oil droplets and water-soluble fraction) and water-soluble fractions (WSF) of oil. When Atlantic cod larvae were exposed to WSF (containing 1.31±0.31μg ∑PAH/L for 4days), expression of GSTM3 and GSTO1 was significantly increased, whereas no differences in GST expression were observed in larvae exposed to a corresponding 50% lower amount of dispersed oil (containing 0.36±0.10μg ∑PAH/L for 4days). The study suggest that although the oil clearly had severe negative effects on the larvae (i.e. concentration-dependent lethality and growth reduction), only minor effects on GST transcription could be observed using RNA obtained from pooled whole-larvae homogenates. This result indicates that the expression of these important detoxification enzymes is only moderately inducible at such an early developmental stage either reflecting low tolerance of cod larvae to dispersed oil or alternatively that using whole-larvae homogenates may have masked tissue-specific mRNA induction. [Copyright &y& Elsevier]