Journal articles: 'Dispersed oil'

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TORRICE, MICHAEL. "DISPERSED OIL RAISES CONCERNS." Chemical & Engineering News 88, no. 21 (May 24, 2010): 8. http://dx.doi.org/10.1021/cen-v088n021.p008.

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Ambrose, Philippa. "Oil slick swiftly dispersed." Marine Pollution Bulletin 21, no. 6 (June 1990): 265. http://dx.doi.org/10.1016/0025-326x(90)90569-t.

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Deeva, V. S., S. М. Slobodyan, and V. S. Teterin. "Optimization of Oil Particles Separation Disperser Parameters." Materials Science Forum 870 (September 2016): 677–82. http://dx.doi.org/10.4028/www.scientific.net/msf.870.677.

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Retaining structure of homogeneous fluid and granular stream is one of the main criteria for technological process assuring the high quality outcome in many industries, including mechanical engineering and oil & gas industry. For example, in oil and gas industry during the pipeline transportation of oils there is a strong trend for cluster aggregation, and particle coarsening and entanglement. Dehomogenization of particle stream results in reverse dynamics of the stream. The importance of prevention and minimization of small particles coalescence by separating the oil stream leads to the need of improving the properties of the dispersers to boost their efficiency. Our paper investigates the operating principle of the disperser for separating particles (separator), which is designed by the authors. We have considered a particle stream of dispersed structure. We have obtained the conformity with the stability of the disperser operation. To yield the results we use the extremum problems for differential equations. This approach provides strong evidence that there are optimum parameters of the dispersers, which result in better stability of the particle stream.

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Butler, James N. "USING OIL SPILL DISPERSANTS ON THE SEA." International Oil Spill Conference Proceedings 1989, no. 1 (February 1, 1989): 343–53. http://dx.doi.org/10.7901/2169-3358-1989-1-343.

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ABSTRACT Primary consideration in this critical review was given to treating oil spills at sea with the intent of reducing the environmental impact of that oil if it should reach the shore. The general conclusions reached were:In carefully planned and monitored laboratory and sea tests, oil has been effectively dispersed; but at many field tests and at accidental spills, reported effectiveness has been low—perhaps because of poor targeting and distribution of aerial sprays, because the oils were too viscous to be dispersable, or the observations of effectiveness were inconclusive.The acute lethal toxicities of dispersant formulations currently in use are usually lower than those of the more volatile and soluble fractions of crude oils and their refined products; hence the toxicity of dispersed oil is due primarily to the oil and not to the dispersant.Sublethal effects of dispersed oil observed in the laboratory occur in most cases at concentrations comparable to or higher than those expected in the water column during treatment of an oil slick at sea (1 to 10 ppm) but seldom at concentrations less than are found several hours after treatment (less than 1 ppm). Since the times of exposure in the laboratory are much longer than predicted exposures during slick dispersal at sea (one to three hours), the effects would be correspondingly less.In open waters, organisms on the surface will be less affected by dispersed oil than by an oil slick, but organisms in the upper water column will experience greater exposure to oil components if the oil is dispersed. In shallow habitats with poor water circulation, benthic organisms will be more immediately affected by dispersed than untreated oil. Long-term effects of dispersed oil on some habitats, such as mangroves, are less, and the habitat recovers faster if the oil is dispersed before it reaches that area.Because the principal benefit of dispersant use is to prevent oil stranding on sensitive shorelines, and because dispersability of oil decreases rapidly with weathering, prompt response is essential.

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Anderson, Jack W., Steven L. Kiesser, Dennis L. McQuerry, and Gilbert W. Fellingham. "EFFECTS OF OIL AND CHEMICALLY DISPERSED OIL IN SEDIMENTS ON CLAMS1." International Oil Spill Conference Proceedings 1985, no. 1 (February 1, 1985): 349–53. http://dx.doi.org/10.7901/2169-3358-1985-1-349.

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ABSTRACT Several field experiments with natural sediments in the intertidal zone were conducted over a two-year period to compare the effects of Prudhoe Bay crude oil and this same oil dispersed with Corexit® 9527 (1 part Corexit to 10 parts oil). The clams used were Protothaca staminea and Macoma inquinata. Exposure periods ranged from one to six months. In a one-month exposure to about 2,000 parts per million (ppm) total oil in sediments, survival of P. staminea was two to three times greater than that of M. inquinata, and both species exhibited lower tolerance to oil alone in sediment than dispersed oil at the same concentration. However, uptake of naphthalenes and phenanthrenes by M. inquinata was greater from sediments mixed with dispersed oil than oil alone. Dispersed oil in this 30-day exposure also produced a decrease (compared to field controls) in the concentration of some of the free amino acids in the tissues of M. inquinata. Four- and six-month field exposures of small P. staminea to sediment containing oil or dispersed oil (about 2,000 ppm) reduced growth in both oil treatments (four-month exposure) or in just the chemically dispersed oil treatment (six-month exposure). In the latter experiment initial petroleum concentrations in the surface sediments (top 3 centimeters) were higher (about 3,000 ppm) for the dispersed oil than for oil alone. Surface layers in both conditions were free of contamination (down to 6 cm) after six months.

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Railsback, Steven F., Gordon A. Robilliard, and Jack R. Mortenson. "STRATEGY FOR MONITORING THE SHORT-TERM DISTRIBUTION OF DISPERSED OILS." International Oil Spill Conference Proceedings 1987, no. 1 (April 1, 1987): 321–24. http://dx.doi.org/10.7901/2169-3358-1987-1-321.

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ABSTRACT An experimental program for monitoring the short-term distribution and concentration of chemically dispersed oil slicks has been developed for Clean Bay, the San Francisco area oil spill cleanup cooperative. The methods used in the program are experimental and still under development. The objectives of the program are to (1) document the surface area and volume of water affected by dispersed oil, (2) estimate the effectiveness of the dispersant, (3) determine the peak oil-dispersant concentration, and (4) determine the range of oil-dispersant concentrations in the affected water. Additional objectives that may be attained if field conditions are acceptable are to (5) estimate the rate at which oil disperses downward, and (6) estimate what fraction of the light-molecular-weight hydrocarbons are evaporated after application of the dispersant. The program includes oil concentration measurements made with a field fluorometer and by laboratory analysis. The program is flexibly designed so that it can be adapted to a variety of field conditions.

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Gulec, Ismail, Brian Leonard, and Douglas A. Holdway. "Oil and dispersed oil toxicity to amphipods and snails." Spill Science & Technology Bulletin 4, no. 1 (January 1997): 1–6. http://dx.doi.org/10.1016/s1353-2561(97)00003-0.

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Crescenzi, Francesco, Marcello Camilli, Eugenio Fascetti, Filippo Porcelli, Giulio Prosperi, and Pasquale Sacceddu. "Microbial Degradation of Biosurfactant Dispersed Oil." International Oil Spill Conference Proceedings 1999, no. 1 (March 1, 1999): 1039–42. http://dx.doi.org/10.7901/2169-3358-1999-1-1039.

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ABSTRACT Biological degradation of a light crude dispersed in sea water by a surfactant produced by an hydrocarbon degrading microorganism has been monitored in laboratory tests. Oligotrophic natural sea water was used with no additions. Results showed that the oil dispersed by the biosurfactant was more easily degraded than chemically dispersed oil. In adhesion tests it has been found that the number of microbial cells adhering to a water/hexadecane interface increases in presence of the biosurfactant. It is suggested that the biodegradation enhancement may be linked to a promoting action carried by the biosurfactant on the adhesion of degrading microorganisms onto the surface of the oil.

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Srinivas, V., Dedeepya Valluripally, P. V. Manikanta, and V. Satish. "Anti Friction Properties of Motor Oil Dispersed with WS₂ and MoS₂ Nanoparticles." Applied Mechanics and Materials 592-594 (July 2014): 1272–76. http://dx.doi.org/10.4028/www.scientific.net/amm.592-594.1272.

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This works presents a study on anti friction properties, of fully formulated SAE 20W 40 grade motor oil dispersed with surface modified WS2and MoS2nanoparticles. WS2and MoS2particles of 0.05 wt. % and 0.1 wt. % have been dispersed in SAE 20W 40 motor oil by Sonication and tested for tribological behavior on pin on disc apparatus as per ASTM G99 standards. The friction coefficient values for base oil and oil dispersed with WS2and MoS2nanoparticles have been evaluated and compared to obtain the performance analysis. Performance graphs have plotted for the base oil and oil dispersed with nanoparticles for comparison. The oils with dispersed nanoparticles have shown enhanced performance in comparison to the base oils in terms of anti friction properties.

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Le Floch, Stéphane, Mathieu Dussauze, François-Xavier Merlin, Guy Claireaux, Michael Theron, Philippe Le Maire, and Annabelle Nicolas-Kopec. "DISCOBIOL: Assessment of the Impact of Dispersant Use for Oil Spill Response in Coastal or Estuarine Areas." International Oil Spill Conference Proceedings 2014, no. 1 (May 1, 2014): 491–503. http://dx.doi.org/10.7901/2169-3358-2014.1.491.

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ABSTRACT Dispersants are known to be an appropriate solution for offshore spill response when sea conditions provide enough energy to disperse and then dilute oil into surface waters. In shallow coastal areas, the use of dispersant is restricted due to the potential that the dispersed oil might come into contact with sensitive resources before dilution can take place. However, after assessing the advantages and potential risks of dispersing oil in coastal areas, it may emerge after careful consideration that and in some cases the use of dispersants could provide a net environmental benefit. The DISCOBIOL research program aimed to provide practical recommendations on dispersant use in coastal and estuarine areas by acquiring relevant (in terms of likely dispersed oil concentrations) and robust experimental information on the impact of mechanically and chemically dispersed oil on living resources. The main conclusion from these experiments was that there is no significant difference between the impacts from oil with and without dispersant use in terms of acute toxicity. However there are some observable sub-lethal effects from exposure to dispersed oil which do not persist more than a few weeks. In a natural environment, on a medium or long timescale, biota which have been exposed to oil (with and without dispersant) do exhibit some symptoms which could affect their survival rate in the field even though they do not lead to acute toxicity effects. However the DISCOBIOL project demonstrated that effects of dispersed oil were less severe than previously recorded for near shore environments. In terms of applying these results to decision making at an oil spill, it highlights the need in coastal areas prior to the use of dispersant to complete a “Net Environmental Benefit Analysis” (NEBA) to determine whether the use of dispersant is expected to minimize the overall damage resulting from the pollution. As it is difficult to cover the number of possible spill scenarios at the contingency planning stage, instead of completing a NEBA, many countries define geographical limits where dispersion can be undertaken, based on the water depth and the distance to the shore as well as the presence of sensitive resources. The DISCOBIOL study confirmed the appropriateness of these pre-defined limits for France's coastal waters but demonstrated that they could be less restrictive since the exposure to dispersed oil could be at least five times higher than was previously considered the safe limit.

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Beegle-Krause, CJ, Tor Nordam, Emlyn John Davies, Alex Nimmo Smith, Miles McPhee, Liv-Guri Faksness, Mark Reed, Ragnhild Lundmark Daae, and Ephim Golbraikh. "Oil Droplet Surfacing Probabilities Under Realistic Low Turbulence in Arctic Ice." International Oil Spill Conference Proceedings 2017, no. 1 (May 1, 2017): 2204–18. http://dx.doi.org/10.7901/2169-3358-2017.1.2204.

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ABSTRACT 2017-081 Responders need to choose among oil spill response options to combat spills in ice covered waters as effectively as possible. A decision to apply dispersants in remote ice covered waters requires an estimation of whether or not the oil will initially disperse and then remain dispersed. A concern is that an effectively dispersed plume of oil will not remain dispersed under ice because the mixing energy required is insufficient. We are advancing the predictive capability to determine whether small oil droplets will rise in the calmer, more stable conditions that can occur in ice covered waters. The results will be presented as lookup tables that can be used to assess whether or not oil has been successfully dispersed in ice covered waters. Ice covered waters can have very low vertical turbulence (mixing) energy, so smaller droplets may rise to the surface in ice covered waters than in open water at lower latitudes. Laboratory studies with oil droplets and field experiments to measure the turbulence directly under ice are being used to provide input and validation data to numerically simulate an oil spill in ice. We assumed that oil slicks were effectively dispersed to form plumes in the water column. Dispersion was assumed to be from natural mixing energy or forced by applying the propeller wash from vessels. The numerical simulations will be performed to determine if these dispersed plumes could significantly resurface. The International Oil and Gas Producers (IOGP) funded the Joint Industry Project (JIP) “Fate of Dispersed Oil Under Ice”. Sintef led two field campaigns (2015 and 2016) with fast ice (ice attached to land) in Van Miljenfjorden in Svalbard. These data for realistic water currents and mixing energy (turbulence) were used in model development. In the second field experiment, dye was released and followed under the ice in order to measure dilution of the dye, as a check on our model. Neap tide periods were targeted in order to look at low mixing energy conditions. At the Plymouth University mesoscale laboratory, studies in a 30 m flume allowed oil droplets of known size to be released in water flowing under synthetic ice under controlled water velocity and under ice roughness conditions. In addition, an analytical model is being developed to estimate the magnitude and dissipation rate of prop wash turbulence. This was necessary to give the time zero basis for estimating how quickly droplets produced by prop wash would rise to the surface. Size classes of oil droplets that do not rise in low vertical turbulence will certainly not rise in higher turbulence. This will allow future research to target larger oil droplet size classes in the Marginal Ice Zone (MIZ). This project was led by SINTEF (Norway) with participation by McPhee Research (USA), University of Plymouth (UK), and Ben Gurion University (Israel).

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Henry, Charles B., Paulene O. Roberts, and Edward B. Overton. "A Primer on in Situ Fluorometry to Monitor Dispersed Oil." International Oil Spill Conference Proceedings 1999, no. 1 (March 1, 1999): 225–28. http://dx.doi.org/10.7901/2169-3358-1999-1-225.

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ABSTRACT A flow-through fluorometry system is a valuable tool for measuring dispersed oil concentrations real-time in freshwater and marine environments. As part of the new Scientific Monitoring of Advanced Response Technologies (SMART), fluorometers are used to investigate dispersant efficacy and dispersed oil transport. Using fluorometers in situ to accurately measure dispersed oil concentrations is not a trivial task: detector response values vary due to oil composition, oil weathering changes response factors, dispersed oil is not a true solution, and natural waters contribute matrix effects and background fluorescence. Based on recent experiences and building upon research conducted in the 1980's, the most effective and accurate method to estimate the dispersed oil concentrations is through real-time water grab samples analyzed by laboratory methodologies for in vitro dispersed oil toxicity quantification. Once analyzed, the field water results can be used to establish a response curve, converting raw field response values into oil concentrations. The continuous record created by the flow-through fluorometer provides a far more comprehensive assessment than collecting a few water samples for laboratory analysis. The combination of using a real-time fluorometer in conjunction with field water sampling is a far superior approach than either method alone. The art and science of in situ fluorometry for measuring dispersed oil will be demonstrated using both laboratory and actual field data.

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Personna, Yves Robert, Michel C. Boufadel, and Shuangyi Zhang. "Biodegradation of Dispersed Endicott Oil in Controlled Experiments." International Oil Spill Conference Proceedings 2014, no. 1 (May 1, 2014): 1126–40. http://dx.doi.org/10.7901/2169-3358-2014.1.1126.

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ABSTRACT We investigate aerobic biodegradation of dispersed Endicott oil in seawater at 15±0.5 °C in laboratory flasks. The objectives of the experiments were to (1) compare the biodegradability of chemically dispersed oil by Corexit 9500 with physically dispersed oil, and (2) determine whether the addition of nutrient affects the biodegradation rates of dispersed oil. The seawater samples (~ 6.5 g/L i.e. brackish water) were collected from Prince William Sound, Alaska. The biodegradation of Endicott oil was investigated for a period of 42 days under high nutrient (HN) (addition of 100 mg NO3-N/L and 10 mg PO4-P/L to background brackish water) and low nutrient (LN) (background brackish water) treatments. In the physically dispersed microcosms, oil biodegradation remained negligible for both HN and LN treatments. However, in the chemically dispersed oil microcosms, 24% and 14% of the total oil biodegraded in the HN (initial concentration= 0.304±0.095 g/L) and LN (initial concentration= 0.298±0.041 g/L) treatments within two weeks, respectively. These results demonstrated that the use of chemical dispersants coupled with nutrient addition can accelerate oil biodegradation. These findings can help develop better bioremediation strategies for addressing oil spills in the sea by focusing on simultaneous operations for rapid oil dispersion and stimulation of microbial growth through the availability of nutrients.

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Fingas, Merv. "OIL SPILL DISPERSION STABILITY AND OIL RE-SURFACING." International Oil Spill Conference Proceedings 2008, no. 1 (May 1, 2008): 661–65. http://dx.doi.org/10.7901/2169-3358-2008-1-661.

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ABSTRACT This paper summarizes the data and the theory of oil-in-water emulsion stability resulting in oil spill dispersion re-surfacing. There is an extensive body of literature on surfactants and interfacial chemistry, including experimental data on emulsion stability. The phenomenon of resurfacing oil is the result of two separate processes: de stabilization of an oil-in-water emulsion and desorption of surfactant from the oil-water interface which leads to further de stabilization. The de stabilization of oil-in-water emulsions such as chemical oil dispersions is a consequence of the fact that no emulsions are thermodynamically stable. Ultimately, natural forces move the emulsions to a stable state, which consists of separated oil and water. What is important is the rate at which this occurs. An emulsion is said to be kinetically stable when significant separation (usually considered to be half or 50% of the dispersed phase) occurs outside of the usable time. There are several forces and processes that result in the destabilization and resurfacing of oil-in-water emulsions such as chemically dispersed oils. These include gravitational forces, surfactant interchange with water and subsequent loss of surfactant to the water column, creaming, coalescence, flocculation, Ostwald ripening, and sedimentation. Gravitational separation is the most important force in the resurfacing of oil droplets from crude oil-in-water emulsions such as dispersions. Droplets in an emulsion tend to move upwards when their density is lower than that of water. Creaming is the de stabilization process that is simply described by the appearance of the starting dispersed phase at the surface. Coalescence is another important de stabilization process. Two droplets that interact as a result of close proximity or collision can form a new larger droplet. The result is to increase the droplet size and the rise rate, resulting in accelerated de stabilization of the emulsion. Studies show that coalescence increases with increasing turbidity as collisions between particles become more frequent. Another important phenomenon when considering the stability of dispersed oil, is the absorption/desorption of surfactant from the oil/water interface. In dilute solutions, much of the surfactant in the dispersed droplets ultimately partitions to the water column and thus is lost to the dispersion process. This paper provides a summary of the processes and data from some experiments relevant to oil spill dispersions.

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Wilson, K. G., and P. J. Ralph. "A COMPARISON OF THE EFFECTS OF TAPIS CRUDE OIL AND DISPERSED CRUDE OIL ON SUBTIDAL ZOSTERA CAPRICORNI." International Oil Spill Conference Proceedings 2008, no. 1 (May 1, 2008): 859–64. http://dx.doi.org/10.7901/2169-3358-2008-1-859.

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ABSTRACT Oil spill mitigation managers need to know the effects of chemical dispersants on subtidal seagrass in order to determine the least net environmental impact of their actions. The decision-making process for chemical dispersant use in Australia, known as Net Environmental Benefit Analysis, is compromised in near shore areas due to a lack of information on dispersed oil impacts on subtidal seagrasses. This study aimed to determine the toxic effects of crude oil, dispersed and non-dispersed, on subtidal seagrass and to quantify the exposure amount. Zostera capricorni plants were exposed to a range of concentrations of different oil and dispersant combinations in the field. ?hotosynthetic health was measured using Pulse Amplitude Modulated (PAM) fluorometry and chlorophyll pigment analysis. Oil concentration was calculated in relative oil units using Ultraviolet Fluoresence (UVF) spectrophotometry. Limited photo synthetic impact was detected in Z. capricorni exposed to the water soluble fraction of the non-dispersed Tapis crude oil treatments. No significant photo synthetic impact was evident in the dispersed Tapis crude oil treatment even though the Total Petroleum Hydrocarbon (TPH) concentration in these treatments was higher than in the non-dispersed Tapis crude oil treatments. Plants from both treatments recovered following replenishment from the surrounding seawater. A substantial reduction of the total petroleum hydrocarbons within the mesoscosms over the 10 hour exposure period was evident and would likely suggest a rapid loss of the toxic mixture to the sediments rather than assimilation by the seagrass.

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Boyd, John N., Debra Scholz, and Ann Hayward Walker. "EFFECTS OF OIL AND CHEMICALLY DISPERSED OIL IN THE ENVIRONMENT." International Oil Spill Conference Proceedings 2001, no. 2 (March 1, 2001): 1213–16. http://dx.doi.org/10.7901/2169-3358-2001-2-1213.

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ABSTRACT This paper describes the last phase of a project sponsored by the American Petroleum Institute (API). Using risk communication methodologies, this project was designed to produce three dispersant issue papers as unbiased reference sources that present technical information and study results in non-scientific language for the layman. The third issue paper, currently in press, was designed to provide the decision maker and layman with an understanding of how spilled oil and chemically dispersed oil affect resources in the environment. Synopses of key sections of this paper are presented here. Understanding exposure and effects is a complex task. Exposure to oil alone can cause a variety of adverse effects, including slowed growth, reduced reproduction, and death. Adding dispersants to spilled oil will change the way resources are affected. Today's dispersants are mixtures of solvents and surfactants and, although they can be toxic, are less dangerous than the dispersant products used in the 1960s and 1970s. How the addition of chemical dispersants to spilled oil will change the way resources are impacted has been a difficult question to answer. Decision makers need to understand several concepts to evaluate how different resources will be affected by oil and chemically dispersed oil during a spill. These include understanding toxicity, what the different routes of exposure are for an organism, how resources from different areas (e.g., water column, water surface, bottom dwelling, or intertidal areas) typically are affected by oil exposure, and how the addition of dispersants changes their exposure to oil. These topics are addressed in this paper.

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McFarlin, Kelly, Mary Beth Leigh, and Robert Perkins. "Biodegradation of Oil and Dispersed Oil by Arctic Marine Microorganisms." International Oil Spill Conference Proceedings 2014, no. 1 (May 1, 2014): 300317. http://dx.doi.org/10.7901/2169-3358-2014-1-300317.1.

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As oil exploration and shipping routes expand in Arctic regions, the potential for oil to enter these cold water environments increases. Therefore it becomes important to understand how the indigenous Arctic microbial community will respond to oil. Arctic seawater was incubated with Alaska North Slope (ANS) crude oil to detect the presence of known petroleum degrading microorganisms and to assess how the baseline microbial community changes with inputs of ANS and ANS dispersed with Corexit 9500. Surface seawater was collected from the Chukchi Sea in near shore (Barrow, AK) and offshore (Hanna Shoal Study Area) environments to provide an indigenous consortium of microorganisms. Incubations were conducted at the temperature of the ocean at the time of collection (-1°C and 4°C), with minimal nutrient addition and sampled at 5, 10 and 28 days. To determine the baseline microbial community, seawater was collected from varying water depths within the Hanna Shoal Study Area. All seawater samples were filtered (0.2 μm) and frozen (–80°C) for DNA extraction. Pyrosequencing of 16S rRNA genes provided taxonomic information to identify microbes that are present in near shore and offshore marine environments and microbes that grow in response to oil or chemically dispersed oil. The indigenous Arctic marine microbial community was found to shift in response to the presence of oil and dispersant, providing an indication of the identity of oil degraders.

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Haule, Kamila, and Włodzimierz Freda. "Remote Sensing of Dispersed Oil Pollution in the Ocean—The Role of Chlorophyll Concentration." Sensors 21, no. 10 (May 13, 2021): 3387. http://dx.doi.org/10.3390/s21103387.

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In the contrary to surface oil slicks, dispersed oil pollution is not yet detected or monitored on regular basis. The possible range of changes of the local optical properties of seawater caused by the occurrence of dispersed oil, as well as the dependencies of changes on various physical and environmental factors, can be estimated using simulation techniques. Two models were combined to examine the influence of oceanic water type on the visibility of dispersed oil: the Monte Carlo radiative transfer model and the Lorenz–Mie model for spherical oil droplets suspended in seawater. Remote sensing reflectance, Rrs, was compared for natural ocean water models representing oligotrophic, mesotrophic and eutrophic environments (characterized by chlorophyll-a concentrations of 0.1, 1 and 10 mg/m3, respectively) and polluted by three different kinds of oils: biodiesel, lubricant oil and crude oil. We found out that dispersed oil usually increases Rrs values for all types of seawater, with the highest effect for the oligotrophic ocean. In the clearest studied waters, the absolute values of Rrs increased 2–6 times after simulated dispersed oil pollution, while Rrs band ratios routinely applied in bio-optical models decreased up to 80%. The color index, CI, was nearly double reduced by dispersed biodiesel BD and lubricant oil CL, but more than doubled by crude oil FL.

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Thorhaug, Anitra, Franklin McDonald, Beverly Miller, Valerie Gordon, John McFarlane, Barbara Carby, Marcel Anderson, and Peter Gayle. "DISPERSED OIL EFFECTS ON TROPICAL HABITATS: PRELIMINARY LABORATORY RESULTS OF DISPERSED OIL TESTING ON JAMAICA CORALS AND SEAGRASS." International Oil Spill Conference Proceedings 1989, no. 1 (February 1, 1989): 455–58. http://dx.doi.org/10.7901/2169-3358-1989-1-455.

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ABSTRACT The island of Jamaica experiences six small- to medium-sized oil spills per year. Major ports for petroleum entry are close to mangrove, seagrass and coral resources. Mangrove and coral habitats form important nurseries for fish and shrimp populations. The coral reefs and white sand beaches of the north and west coasts are the basis of the tourism industry, which generates $406 million U.S. dollars per year, and accounts for 55 percent of the island's foreign exchange earnings. Thus, protecting these resources from the effects of spilled oil is of priority to the government. Mechanical means are clearly not the solution in a variety of spills. Also, no maps exist to guide the on-scene coordinator (OSC) in oil spill management. To initiate a study of dispersed oil and formulate a command map, habitat-dispersed oil toxicity testing on three species of seagrasses, three indicator species of coral, and three mangroves has been conducted in Jamaica. Ten dispersants and their dispersed oil toxicity in these habitats will be ranked. In general, the coral toxicity parallels the seagrass response to the dispersants. Responses of the coral to intermediate-toxicity dispersants differed widely. Black, white, and red mangroves also were tested. This is the first time comprehensive among-dispersant and among-species dispersant testing has been carried out in the tropics.

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Haule, Kamila, and Henryk Toczek. "FLUORESCENCE PROPERTIES OF MECHANICALLY DISPERSED CRUDE OIL." Journal of KONES. Powertrain and Transport 21, no. 4 (January 1, 2014): 161–67. http://dx.doi.org/10.5604/12314005.1130464.

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Bera, Gopal, Shawn Doyle, Uta Passow, Manoj Kamalanathan, Terry L. Wade, Jason B. Sylvan, Jose L. Sericano, Gerardo Gold, Antonietta Quigg, and Anthony H. Knap. "Biological response to dissolved versus dispersed oil." Marine Pollution Bulletin 150 (January 2020): 110713. http://dx.doi.org/10.1016/j.marpolbul.2019.110713.

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Jun, S. H., Y. R. Uhm, and C. K. Rhee. "Tribology Properties of Nanodiamond Dispersed Engine Oil." Journal of Korean Powder Metallurgy Institute 18, no. 5 (October 28, 2011): 417–22. http://dx.doi.org/10.4150/kpmi.2011.18.5.417.

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Khelifa, Ali, Ben Fieldhouse, Zhendi Wang, Chun Yang, Mike Landriault, Carl E. Brown, and Merv Fingas. "EFFECTS OF CHEMICAL DISPERSANT ON OIL SEDIMENTATION DUE TO OIL-SPM FLOCCULATION: EXPERIMENTS WITH THE NIST STANDARD REFERENCE MATERIAL 1941?" International Oil Spill Conference Proceedings 2008, no. 1 (May 1, 2008): 627–31. http://dx.doi.org/10.7901/2169-3358-2008-1-627.

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ABSTRACT As it is well established that application of chemical dispersant to oil slicks enhances the concentration of oil droplets and reduces their size, chemical dispersants are expected to enhance oil sedimentation if applied in coastal waters rich in suspended particulate matter (SPM) and if flocculation between chemically dispersed oil and SPM, which leads to formation of oil-SPM aggregates (OSAs), occurs readily. New laboratory experiments were conducted to establish a quantitative understanding of the process and to verify this hypothesis. This paper presents findings from experiments conducted using Standard Reference Material 1941b prepared by the National Institute of Standards and Technology, Arabian Medium, Alaska North Slope and South Louisiana crude oils, and Corexit 9500 and Corexit 9527 chemical dispersants. Results showed that OSAs do form with chemically dispersed oil. Oil sedimentation increases with sediment concentration and reach a maximum at a sediment-to-oil ratio of approximately 2:1 for most of the oils used. No obvious effect of chemical dispersant on oil sedimentation was measured for sediment concentration of 100 mg/L and higher. However, measured oil sedimentation was 3 to 5 times higher with chemical dispersant than with physically dispersed oil at low sediment concentration of 25 and 50 mg/L. UV epi-fluorescence microscopy showed that OSAs formed with chemically dispersed oil contain many oil droplets that are smaller than those trapped in OSAs formed with physically dispersed oil.

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Haule, Kamila, Henryk Toczek, Karolina Borzycka, and Mirosław Darecki. "Influence of Dispersed Oil on the Remote Sensing Reflectance—Field Experiment in the Baltic Sea." Sensors 21, no. 17 (August 25, 2021): 5733. http://dx.doi.org/10.3390/s21175733.

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Remote sensing techniques currently used to detect oil spills have not yet demonstrated their applicability to dispersed forms of oil. However, oil droplets dispersed in seawater are known to modify the local optical properties and, consequently, the upwelling light flux. Theoretically possible, passive remote detection of oil droplets was never tested in the offshore conditions. This study presents a field experiment which demonstrates the capability of commercially available sensors to detect significant changes in the remote sensing reflectance Rrs of seawater polluted by six types of dispersed oils (two crude oils, cylinder lubricant, biodiesel, and two marine gear lubricants). The experiment was based on the comparison of the upwelling radiance Lu measured in a transparent tank floating in full immersion in seawater in the Southern Baltic Sea. The tank was first filled with natural seawater and then polluted by dispersed oils in five consecutive concentrations of 1–15 ppm. After addition of dispersed oils, spectra of Rrs noticeably increased and the maximal increase varied from 40% to over three-fold at the highest oil droplet concentration. Moreover, the most affected Rrs band ratios and band differences were analyzed and are discussed in the context of future construction of algorithms for dispersed oil detection.

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Ward, Greg A., Bart Baca, Wendy Cyriacks, Richard E. Dodge, and Anthony Knap. "Continuing Long-Term Studies of the Tropics Panama Oil and Dispersed Oil Spill Sites." International Oil Spill Conference Proceedings 2003, no. 1 (April 1, 2003): 259–67. http://dx.doi.org/10.7901/2169-3358-2003-1-259.

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ABSTRACT The TROPICS (Tropical Oil Pollution Investigations in Coastal Systems) oil spill experiment was conducted on the Caribbean coast of Panama, near Bocas del Toro. In November 1984, crude and dispersed crude oil were released in two separate boom-enclosed areas representative of intertidal mangrove and subtidal seagrass/coral ecosystems. The present information is based on site visits over the past two years, including 2002. Following the degradation of oil over the past 18 years, sheen identified from the spilled oil in 1994 is still visible in non-dispersed Oil Site sediments. In mangroves, previously denuded areas exposed to crude oil are currently occupied by new seedlings and saplings, which are growing rapidly but with morphological prop-root deformations. Tree mortality occurred in both the Dispersed Oil and Reference Sites, but was non-localized and appeared as natural mortality in aged trees. Recent data have revealed an invasion of seagrass beds by finger coral at the Oil Site. Since treatment, percent coverage of corals at this site has grown from a pretreatment value of 33.5% in March 1984 to 67.5% in June 2001.

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Gulec, Ismail, and Douglas A. Holdway. "TOXICITY OF DISPERSANT, OIL, AND DISPERSED OIL TO TWO MARINE ORGANISMS." International Oil Spill Conference Proceedings 1997, no. 1 (April 1, 1997): 1010–11. http://dx.doi.org/10.7901/2169-3358-1997-1-1010.

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ABSTRACT Acute lethal bioassays using semistatic conditions were conducted to assess the toxicity of crude oil, dispersant, and dispersed oil using the amphipod Allorchestes compressa as a test species. Sublethal bioassays (suppression of burying behavior over 24 hours of exposure) were conducted for these toxicants using the marine sand snail Polinices conicus. Both lethal and sublethal bioassays were also carried out for two reference toxicants: sodium dodecyl sulphate (SDS) and zinc sulphate.

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Sterling, M. C., R. L. Autenrieth, J. S. Bonner, C. B. Fuller, C. A. Page, T. Ojo, and A. N. S. Ernest. "Dispersant Effectiveness and Toxicity—An Integrated Approach." International Oil Spill Conference Proceedings 2003, no. 1 (April 1, 2003): 335–39. http://dx.doi.org/10.7901/2169-3358-2003-1-335.

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ABSTRACT An integrated approach to study chemical dispersant effectiveness and dispersed oil toxicity is presented. Conventional lab scale effectiveness tests generally provide a measure of overall dispersant effectiveness. However, chemical dispersion can be viewed as two processes: (1) dispersant-oil slick mixing and (2) oil droplet transport into the water column. Inefficiencies in either process limit the overall dispersant effectiveness. This laboratory study centered on the latter process and was conducted to focus on the impacts of water column hydrodynamics on the resurfacing of dispersed oil droplets. Using a droplet coalescence model (Sterling et al., 2002), the droplet coalescence rates of dispersed crude oil was determined within a range of shear rates. A controlled shear batch reactor was created in which coalescence of dispersed oil droplets were monitored in-situ. Experimental dispersion efficiencies (C/C0) and droplet size distributions were compared to those predicted by Stokes resurfacing. Experimental C/C0 values were lower than that predicted from Stokes resurfacing. Experimental dispersion efficiency values (C/C0) decreased linearly with increasing mean shear rates due to increased coalescence rates. These results suggested that dispersed oil droplet coalescence in the water column can adversely impact overall dispersant efficiency. To avoid high control mortality in toxicity testing, the toxicity exposure chamber was designed with separate compartments for scaled mixing and organism exposure, respectively. Chamber design includes continuous re-circulation between mixing and exposure chamber. A 1-minute exposure compartment residence time was determined from tracer studies indicating virtually identical oil concentrations in the mixing and exposure compartments. In addition, the 96-hour mortality of 14-day oil Menidia beryllina varied from 2% in the no-oil control tests to 87% in the dispersed oil (200 mg/L) tests. These results show the effectiveness of the integrated vessel for the characterization and toxicity testing of oil dispersions.

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La Schiazza, José, Jorge Rodriguez-Grau, and Freddy Losada. "EFFECTS OF A DISPERSED OIL SPILL ON BIOFOULING COMMUNITIES." International Oil Spill Conference Proceedings 1997, no. 1 (April 1, 1997): 1034–35. http://dx.doi.org/10.7901/2169-3358-1997-1-1034.

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ABSTRACT Biofouling communities (groups of encrusting organisms) growing on Plexiglas plates were selected as bioindicators to evaluate the effects of a simulated dispersed crude oil spill. Results showed significant changes in the number of taxa, abundance, and percentage of substrate cover between treated and control groups; however, these effects represent a relatively low biological impact produced by the dispersed oil. The overall conclusion is that biofouling has a high recovery capacity despite an actual acute disturbance, since many biofouling organisms showed a significant resistance to the effects of dispersed crude oil.

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Mukherjee, Biplab, and Brian A. Wrenn. "Size distribution as a measure of dispersant performanceA paper submitted to the Journal of Environmental and Engineering Science." Canadian Journal of Civil Engineering 36, no. 3 (March 2009): 540–49. http://dx.doi.org/10.1139/l08-147.

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Study of the chemical dispersion of crude oil using size distribution methods can provide important information needed for oil-spill response strategy, which is lacking in the more commonly used mass–concentration methods. Therefore, identification of a reliable method or methods that can provide accurate information regarding droplet size and the mass of oil dispersed is necessary. This research compared four such methods. Gravimetric analysis of the oil mass dispersed was biased low due to loss of volatile components, whereas UV spectroscopy provided accurate results. Size–distribution data obtained using an optical particle counter (OPC) produced accurate estimates of oil mass dispersed, but microscopic examination produced inaccurate and poorly reproducible estimates. Although size–distribution metrics (e.g., estimates of the mean diameter of the size distribution) produced by the two methods were similar, microscopic examination gave unreliable estimates of the number concentration of dispersed oil droplets due to the relatively small number of observations relative to the OPC.

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Varadaraj, R., M. L. Robbins, J. Bock, S. Pace, and D. MacDonald. "DISPERSION AND BIODEGRADATION OF OIL SPILLS ON WATER." International Oil Spill Conference Proceedings 1995, no. 1 (February 1, 1995): 101–6. http://dx.doi.org/10.7901/2169-3358-1995-1-101.

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ABSTRACT Published literature indicates that oil spill dispersion by chemical dispersants will enhance biodegradation because of the increase in interfacial area. However, some of the literature is contradictory concerning whether the use of surfactants will enhance or temporarily inhibit biodegradation, suggesting that more than one mechanism is at work. We set out to study the correlation between the area of dispersed oil droplets and the rate and extent of microbial oil degradation using sorbitan surfactants. We varied the surfactant blend hydrophile-lipophile balance (HLB) and treat level in a statistically designed experiment. Both dispersed area and percent oil degraded at a given time were shown to depend on surfactant HLB and treat level, but to different degrees. The difference was accounted for by demonstrating that percent oil degraded depended on both dispersed area and percent sorbitan in the dispersant treat. The quantitative finding that both dispersed area and surfactant chemistry control microbial growth and oil biodegradation explains the apparent contradiction that some good dispersants enhance, while others temporarily inhibit, degradation. Corexit 9500 dispersant was observed to have a positive influence on biodegradation of oil on water.

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Lessard, Richard R., Don Aurand, Gina Coelho, Chris Fuller, Thomas J. McDonald, Jim Clark, Gail Bragin, Robin Jamail, and Alexis Steen. "Design and Implementation of a Mesocosm Experiment On The Environmental Consequences of Nearshore Dispersant Use." International Oil Spill Conference Proceedings 1999, no. 1 (March 1, 1999): 1027–30. http://dx.doi.org/10.7901/2169-3358-1999-1-1027.

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ABSTRACT In April 1998 the first full-scale oil spill experiment was run at the Coastal Oilspill Simulation System (COSS) Facility in Corpus Christi, Texas. The facility contains nine 110-foot long, eight-foot deep wave tanks for simulated nearshore or intertidal habitat experiments. Features include an adjustable 2-foot tidal range, variable flow rate, and random wave capability. Sediment can be added to create bottom habitat and to develop an intertidal “shoreline.” The project compared the ecological effects when oil is allowed to strand on the beach to the effects when dispersed oil is present in very shallow areas. Untreated and dispersed weathered Arabian Medium crude oil was released in three tanks each. Two other tanks served as controls. The fate and effects of the oil or dispersed oil were evaluated over ten days using caged marine species and detailed hydrocarbon chemistry. The tests were successfully completed, demonstrating the facility's impressive potential for similar experiments. Preliminary data analyses indicate that water column effects of dispersed oil were not significantly different from those of untreated oil, and the use of dispersant led to a clear reduction in shoreline accumulation of oil.

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Olsvik, Pål A., Kai K. Lie, Trond Nordtug, and Bjørn Henrik Hansen. "Is chemically dispersed oil more toxic to Atlantic cod (Gadus morhua) larvae than mechanically dispersed oil? A transcriptional evaluation." BMC Genomics 13, no. 1 (2012): 702. http://dx.doi.org/10.1186/1471-2164-13-702.

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Pace, Charles B., James R. Clark, and Gail E. Bragin. "COMPARING CRUDE OIL TOXICITY UNDER STANDARD AND ENVIRONMENTALLY REALISTIC EXPOSURES." International Oil Spill Conference Proceedings 1995, no. 1 (February 1, 1995): 1003–4. http://dx.doi.org/10.7901/2169-3358-1995-1-1003.

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ABSTRACT Standard aquatic toxicity tests do not address real-world, spiked exposure scenarios that occur during oil spills. We evaluated differences in toxicity of physically and chemically dispersed Kuwait crude oil to mysids (Mysidopsis bahia) under continuous and spiked (half-life of 2 hours) exposure conditions. The 96-hr LC50s for physically dispersed oil were 0.78 mg/L (continuous) and >2.9 mg/L (spiked), measured as total petroleum hydrocarbons (TPH). Values for chemically dispersed oil were 0.98 mg/L (continuous) and 17.7 mg/L (spiked) TPH. Continuous-exposure tests may overestimate the potential for toxic effects under real-world conditions by a factor of 18 or more.

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Fiocco, Robert J., and Alun Lewis. "Oil Spill Dispersants." Pure and Applied Chemistry 71, no. 1 (January 1, 1999): 27–42. http://dx.doi.org/10.1351/pac199971010027.

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Introduction: The purpose of any oil spill response is to minimise the damage that could be caused by the spill. Dispersants are one of the limited number of practical responses that are available to respond to oil spills at sea.When oil is spilled at sea, a small proportion will be naturally dispersed by the mixing action caused by waves. This process can be slow and proceed to only a limited extent for most situations. Dispersants are used to accelerate the removal of oil from the surface of the sea by greatly enhancing the rate of natural dispersion of oil and thus prevent it from coming ashore. Dispersed oil will also be more rapidly biodegraded by naturally occurring microorganisms. The rationale for dispersant use is that dispersed oil is likely to have less overall environmental impact than oil that persists on the surface of the sea, drifts and eventually contaminates the shoreline. The development of modern dispersants began after the Torrey Canyon oil spill in 1967. Many lessons have been learned since that spill, and consequently the modern dispersants and application techniques in use today have become an effective way of responding to an oil spill. For example, the dispersant response to the Sea Empress spill in 1996 demonstrated that dispersants can be very effective and prevent a much greater amount of environmental damage from being caused (6). This chapter describes the chemistry and physics of dispersants, planning and decision-making considerations, and finally their practical application and operational use in oil spill response.

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Liu, Hong Jing, Ying Zhang, Hui Yao, and Wei Zhao. "Study on Propylene Recovery in a Dispersed Absorption System-(Water-in-Oil) Emulsion System." Advanced Materials Research 383-390 (November 2011): 6151–55. http://dx.doi.org/10.4028/www.scientific.net/amr.383-390.6151.

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The purpose of the paper is to investigate propylene recovery by a new absorption system, namely water-in-oil emulsion absorbent. Water in oil emulsion, in which kerosene used as oil phase with dispersed water droplet, is prepared to be as absorbent to absorb propylene. The effect of volume fraction dispersed phase, dispersed droplet size, and the stirring rate on propylene absorption rate are researched. Experimental results indicate that the absorption rate of propylene can increase 20% compared with traditional absorption method. The volume fraction dispersed phase should be appropriate, otherwise the enhancement absorption can not be attained. The appropriate number is 0.05 for this dispersion. The smaller droplet size of dispersed phase as well as the faster stirring rate can increase the propylene absorption rate. The mechanism of enhancement propylene absorption is attributed to the intensive turbulence in boundary layer between gas and liquid due to the movement of dispersed water droplets.

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Duke, N. C., K. A. Burns, and O. Dalhaus. "EFFECTS OF OILS AND DISPERSED-OILS ON MANGROVE SEEDLINGS IN PLANTHOUSE EXPERIMENTS: A PRELIMINARY ASSESSMENT OF RESULTS TWO MONTHS AFTER OIL TREATMENTS." APPEA Journal 38, no. 1 (1998): 631. http://dx.doi.org/10.1071/aj97039.

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The effects of oil and dispersed-oil treatments on mangrove seedlings, grown in artificial tidal systems in tropical north-eastern Australia, were assessed two months after application. Seedling mortality was used as a measure of treatment toxicity. All oils and dispersed-oils were toxic to mangrove seedlings although the effect of Bunker C was quite low. Overall, oils and dispersed-oils were ordered by increasing toxicity: Bunker C fuel, Arabian Light crude, Gippsland Light crude, Thevenard crude, and Woodside condensate. Toxicity of oils correlated with viscosity, where low toxicity of the heavy fuel oil (3 per cent mortality) stood in marked contrast with high levels of mortality scored for very light crude oils, Thevenard (73 per cent) and Woodside (85 percent). Mangrove species were ordered by their overall increased vulnerability to oils and dispersed-oils as, Ceriops spp., Rhizophora stylosa, Avicennia marina and Aegiceras corniculatum. As expected, higher doses (2.0 L/m2) showed an overall increase of 30 per cent mortality compared with lower doses (0.2 L/m2). However, values for each grouping of seedlings varied widely, indicating possible synergistic effects of different environmental factors. Despite this, at least one other pattern was evident. Dispersed-oil treatments were usually less toxic to mangrove seedlings than undispersed oils, particularly for high doses. This result needs to be further assessed, but it is of interest that added dispersant did not usually result in increased seedling mortality. We will re-evaluate all findings once experiments are completed.

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Page, Cheryl A., Robin L. Autenrieth, James S. Bonner, and Thomas McDonald. "BEHAVIOR OF CHEMICALLY DISPERSED OIL IN A WETLAND ENVIRONMENT." International Oil Spill Conference Proceedings 2001, no. 2 (March 1, 2001): 821–23. http://dx.doi.org/10.7901/2169-3358-2001-2-821.

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ABSTRACT An experiment was conducted at a wetland research facility, investigating the behavior of chemically dispersed oil (CDO) using an oil spill dispersant. The research site is located on the San Jacinto River near Houston, Texas. The experimental treatments included oiled control, “high-dose” CDO (1:10 dispersant-to-oil ratio, DOR), “low-dose” CDO (1:20 DOR), as well as an unoiled control. Fourteen 5 m x 5 m plots were used for the experiment, four plots for each oiled treatment and two plots for the unoiled control. The treatments were assigned to plots using a randomized complete-block design. Twenty-one liters of Arabian medium crude oil was applied systematically to each plot. For the CDO treatments, the premixed dispersant-plus-oil solution was first added to containers of river water (either 1:10:200 or 0.5:10:200 dispersant-oil-water ratios), and the resulting solution was applied systematically to the respective plots. This method of CDO application was designed to simulate the movement of a dispersed-oil plume into a wetland environment. Sediment samples were taken over a 99-day period, using a 5-cm diameter-coring device. The GC-MS results for both target saturate and target aromatic hydrocarbons were normalized to 17?, 21?-(H)hopane to separate biotic and abiotic removal mechanisms and to minimize spatial heterogeneity. Target compound analyses indicated no significant differences in the biodegradation rates for the three oil treatments. There were, however, significant differences in the amount of oil initially flushed (physical removal) from the plots of both CDO treatments as compared to the oiled-control treatment.

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Overholt, Will A., Kala P. Marks, Isabel C. Romero, David J. Hollander, Terry W. Snell, and Joel E. Kostka. "Hydrocarbon-Degrading Bacteria Exhibit a Species-Specific Response to Dispersed Oil while Moderating Ecotoxicity." Applied and Environmental Microbiology 82, no. 2 (November 6, 2015): 518–27. http://dx.doi.org/10.1128/aem.02379-15.

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

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Bocard, C., G. Castaing, J. Ducreyx, and C. Gatellier. "Fate of Chemically Dispersed Oil Related to Sedimentation." Water Science and Technology 18, no. 4-5 (April 1, 1986): 301. http://dx.doi.org/10.2166/wst.1986.0209.

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Fuller, Christopher B., James S. Bonner, Frank Kelly, Cheryl A. Page, and Temitope Ojo. "REALTIME GEO-REFERENCED DETECTION OF DISPERSED OIL PLUMES." International Oil Spill Conference Proceedings 2005, no. 1 (May 1, 2005): 693–96. http://dx.doi.org/10.7901/2169-3358-2005-1-693.

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The current SMART protocol used by the U.S. Coast Guard relies on traditional ex-situ fluorometers that require physical transport of the sample from the water column to the instruments. While sample transport methods are available (e.g. pumps and discrete sampling), they introduce time lags in the data acquisition process. These lags can be a source of error when the data is post analyzed and is not conducive to real-time monitoring efforts, creating significant logistical problems and dispersion (smearing) of the sample stream. Another limitation of the currently-used equipment is that it requires much attention to manually record GPS data which is later used to determine the spatial distribution of an oil plume. Recent developments of in-situ fluorometric instrumentation promise to simplify problems associated with deployment of ex-situ instrumentation (e.g. insuring that pumps are primed) in boat-based field applications. This study first compares the performance of two in-situ fluorometers in a simulated oil and dispersant application at the Shoreline Environmental Research Facility at Texas A&M University in Corpus Christi, Texas. The fluorometers were the WETStar and the ECP-FL3 (both by WETLabs, Inc.). To address issues related to data collection from a GPS and a fluorometer, a system was developed that simultaneously merges data from both instruments into a single file and presents the data real-time as a color-coded ship track. The applicability of this system was tested and evaluated during a spill response exercise conducted by the Texas General Land Office and the U.S. Coast Guard in Galveston Bay, Texas, U.S.A.

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Zlobin, Aleksandr. "Study of structural organization of oil dispersed systems." Вестник Пермского национального исследовательского политехнического университета. Геология. Нефтегазовое и горное дело 17 (2015): 41–53. http://dx.doi.org/10.15593/2224-9923/2015.17.5.

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Lambert, P., M. Goldthorp, B. Fieldhouse, Z. Wang, M. Fingas, L. Pearson, and E. Collazzi. "Field fluorometers as dispersed oil-in-water monitors." Journal of Hazardous Materials 102, no. 1 (August 2003): 57–79. http://dx.doi.org/10.1016/s0304-3894(03)00202-4.

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Kashif, Mohammad, and Sharif Ahmad. "Polyorthotoluidine dispersed castor oil polyurethane anticorrosive nanocomposite coatings." RSC Adv. 4, no. 40 (2014): 20984–99. http://dx.doi.org/10.1039/c4ra00587b.

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Zhang, Yi, Jacques Monnier, and Michio Ikura. "Bio-oil upgrading using dispersed unsupported MoS2 catalyst." Fuel Processing Technology 206 (September 2020): 106403. http://dx.doi.org/10.1016/j.fuproc.2020.106403.

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Gundyrev, A. A., L. P. Kazakova, M. L. Mukhin, and V. V. Kryuchov. "Behavior of dispersed mineral oil in electrical fields." Chemistry and Technology of Fuels and Oils 26, no. 5 (May 1990): 243–47. http://dx.doi.org/10.1007/bf01163890.

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46

Singer, Michael M., Susan Jacobson, Ronald S. Tjeerdema, and Michael Sowby. "ACUTE EFFECTS OF FRESH VERSUS WEATHERED OIL TO MARINE ORGANISMS: CALIFORNIA FINDINGS." International Oil Spill Conference Proceedings 2001, no. 2 (March 1, 2001): 1263–68. http://dx.doi.org/10.7901/2169-3358-2001-2-1263.

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ABSTRACT Early experiences with dispersants led to a widely accepted paradigm in the United States that chemically dispersing oil led to increased ecological damage. Since then, dispersant formulations have evolved significantly, leading many in the oil spill response community to revisit the question of whether or not dispersing oil can help achieve an overall net ecological benefit. Spill response must necessarily involve weighing the costs and benefits of both dispersant use and non-use to resources potentially at risk. The majority of comparative data on the toxicity of dispersed and undispersed oil in the literature to date is based on fresh oil. In most circumstances, however, mounting of dispersant operations requires hours to days, making the use of data based on fresh oil problematic. Laboratory-weathered oil has been used in the evaluation of dispersant effectiveness, but its use in toxicological investigations has been limited. Using standardized methods, the authors have compared the acute aquatic effects of untreated and chemically dispersed oil in both its fresh state, and artificially weathered to simulate approximately 1 day at sea. Oil weathering was done under controlled conditions using accepted, repeatable methods. Findings show that weathering significantly reduces the amount of low molecular weight hydrocarbons, and generally elicits reduced toxicity from both untreated and dispersed oil, compared to fresh oil. Based on actual hydrocarbon exposures, however, in several instances aqueous solutions from dispersed and undispersed oil (both fresh and weathered) were essentially equitoxic.

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Baca, Bart, Eric Rosch, Erik D. DeMicco, and Paul A. Schuler. "TROPICS: 30-year Follow-up and Analysis of Mangroves, Invertebrates, and Hydrocarbons." International Oil Spill Conference Proceedings 2014, no. 1 (May 1, 2014): 1734–48. http://dx.doi.org/10.7901/2169-3358-2014.1.1734.

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ABSTRACT TROPICS (TRopical Oil Pollution Investigations in Coastal Systems) has been the seminal study on trade-offs for Net Environmental Benefit Analysis (NEBA) for dispersant use in tropical ecosystems. The study began in 1983/84 with the identification of suitable tropical island sites in Bahia Almirante, Bocas del Toro, Panama that contained mangrove, seagrass and coral habitats in close enough proximity to establish three 30m X 30m test sites. Controlled releases of Prudhoe Bay crude oil (dosed at 1L/m2) and Prudhoe Bay crude oil pre-dispersed with Corexit 9527 (to maintain 50 ppm water soluble fraction), were introduced into the Non- dispersed oil (Site O) and the Dispersed oil (Site D) sites, respectively, for 48 hours. A nearby Reference site (Site R) was not treated with oil/dispersed oil. Treatments were designed to simulate a realistic oil spill in adjoining mangrove, seagrass, and coral habitats. Following exposure and removal of oil, sites were studied periodically over 30 years for relative effects of dispersed and non-dispersed oil in coral, seagrass, mangrove, and invertebrate populations, as well as hydrocarbon presence. Early research focused on short- and mid-term effects compared to the Reference site (R), while later work focused on long-term effects and ecosystem recovery. In general, researchers found that Site O exhibited more overall long-term ecosystem disruption than Site D, and that Site D had recovered quickly to Site R and baseline levels. In November 2013 (29 years after oil and dispersed oil exposure), the TROPICS sites were re-visited under a grant provided by Clean Caribbean & Americas. Researchers collected data on mangroves, mangrove invertebrates, and hydrocarbons. The density of mangrove trees at Site D had remained at Site R and baseline levels. Site O, which had experienced early die off of trees, followed by peak production at 10 years (far in excess of Site R and baseline levels), exhibited a decline dominated by small trees. Mangrove snails and oysters increased sharply at Site O after the spill, but declined over 10-20 years. Sites D and R maintained gradual invertebrate increases during this time. This paper focuses on research from the November 2013 visit and draws on previous observations and TROPICS papers on overall ecosystem disruption and recovery as it pertains to the NEBA for nearshore dispersant use in tropical marine ecosystems.

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Quek, Check Shyong, Norzita Ngadi, and Muhammad Abbas Ahmad Zaini. "Kinetics and Thermodynamics of Dispersed Oil Sorption by Kapok Fiber." Ecological Chemistry and Engineering S 26, no. 4 (December 1, 2019): 759–72. http://dx.doi.org/10.1515/eces-2019-0053.

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Abstract This work was aimed at evaluating the sorption of dispersed oil by kapok fiber. The physicochemical characteristics of kapok fiber were investigated using BET, SEM, FTIR, XRD, contact angle and elemental analysis. The oil droplet size distribution at different temperatures was analysed using a Coulter counter, and its relationship with sorption was investigated. The effects of dosage, hydraulic retention time and temperature, on the sorption performance were studied. The result indicates that the sorption of dispersed oil by kapok fiber is spontaneous, endothermic and agreed with the pseudo-first-order reaction kinetics. The amount of oil that could be removed is about 28.5 %, while that of water is less than 1 % of the original amount (0.5 dm3). Kapok is a promising natural hydrophobic fiber for dispersed oil removal from oily wastewater.

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Singer, Michael M., Don V. Aurand, Gina M. Coelho, Gail E. Bragin, James R. Clark, Michael Sowby, and Ronald S. Tjeerdema. "MAKING, MEASURING, AND USING WATER-ACCOMMODATED FRACTIONS OF PETROLEUM FOR TOXICITY TESTING." International Oil Spill Conference Proceedings 2001, no. 2 (March 1, 2001): 1269–74. http://dx.doi.org/10.7901/2169-3358-2001-2-1269.

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ABSTRACT Oil spill response can be highly affected by the perceived costs and benefits of a particular countermeasure. Responders' perceptions of these can be influenced by the means in which scientific data are collected and presented. To date, a large amount of information has been generated on the aquatic toxicity of oil, dispersants, and dispersed oil. Unfortunately, many of these data are not comparable because of differing toxicological and analytical methodologies, as well as frequent lack of analytical verification of exposures. Recently, a group of federal, state, academic, and industry representatives from North America and Europe have been working toward standardizing both biological and analytical methods used to produce acute toxicity estimates for complex mixtures such as oil, dispersants, and dispersed oil. This standardization provides guidelines for future investigations to be conducted in a sufficiently rigorous manner to allow both inter- and intra-laboratory dataset comparisons, thus providing a more coherent and robust database from which to derive response guidance. By encouraging the use of these standardizations, it is hoped that decision-makers can be provided with a clearer understanding of the acute toxicological results of oil dispersal, and that such information can be more properly integrated into the response planning and decision-making processes.

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Scholten, M., and J. Kuiper. "THE EFFECTS OF OIL AND CHEMICALLY DISPERSED OIL ON NATURAL PHYTOPLANKTON COMMUNITIES." International Oil Spill Conference Proceedings 1987, no. 1 (April 1, 1987): 255–57. http://dx.doi.org/10.7901/2169-3358-1987-1-255.

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ABSTRACT The effects of various crude oils and chemically dispersed oil on natural phytoplankton communities were tested in several experiments using marine mesocosms. Elevated algal biomass concentrations were found in most of the experiments, despite the long-term inhibition of primary productivity per unit chlorophyll. This result is due to reduced grazing upon algae as a consequence of oil-induced mortality of copepods or bivalves. A rapid succession from a diatom-dominated algae community to one dominated by microflagellates can be observed after an oil spill, owing to the more rapid exhaustion of silicate. If silicate is not being exhausted, a prolonged abundance of diatoms is observed. Treatment of oil with dispersant generally will aggravate effects, because of high dissolved oil concentrations in the water.

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Journal articles on the topic 'Dispersed oil'

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