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Tony Gutierrez - One of the best experts on this subject based on the ideXlab platform.
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chemical Dispersant enhances microbial exopolymer eps production and formation of marine oil Dispersant snow in surface waters of the subarctic northeast atlantic
Frontiers in Microbiology, 2019Co-Authors: Laura Duran Suja, Xindi Chen, Stephen Summers, David M Paterson, Tony GutierrezAbstract:A notable feature of the Deepwater Horizon oil spill was the unprecedented formation of marine oil snow (MOS) that was observed in large quantities floating on the sea surface and that subsequently sedimented to the seafloor. Whilst the physical and chemical processes involved in MOS formation remain unclear, some studies have shown that extracellular polymeric substances (EPS) play a role in this process. Here, we report that during exposure of subarctic northeast Atlantic seawater to a chemical Dispersant, whether in the presence/absence of crude oil, the Dispersant stimulates the production of significant quantities of EPS that we posit serves as a key building block in the formation of MOS. This response is likely conferred via de novo synthesis of EPS by natural communities of bacteria. We also describe the formation of marine Dispersant snow (MDS) as a product of adding chemical Dispersants to seawater. Differential staining confirmed that MDS, like MOS, is composed of glycoprotein, though MDS is more protein rich. Using barcoded-amplicon Illumina MiSeq sequencing, we analyzed, for the first time, the bacterial communities associated with MDS and report that their diversity is not significantly dissimilar to those associated with MOS aggregates. Our findings emphasize the need to conduct further work on the effects of Dispersants when applied to oil spills at sea, particularly at different sites, and to determine how the product of this (i.e., MOS and MDS) affects the biodegradation of the oil.
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Chemical Dispersant Enhances Microbial Exopolymer (EPS) Production and Formation of Marine Oil/Dispersant Snow in Surface Waters of the Subarctic Northeast Atlantic
Frontiers Media S.A., 2019Co-Authors: Laura Duran Suja, Xindi Chen, Stephen Summers, David M Paterson, Tony GutierrezAbstract:A notable feature of the Deepwater Horizon oil spill was the unprecedented formation of marine oil snow (MOS) that was observed in large quantities floating on the sea surface and that subsequently sedimented to the seafloor. Whilst the physical and chemical processes involved in MOS formation remain unclear, some studies have shown that extracellular polymeric substances (EPS) play a role in this process. Here, we report that during exposure of subarctic northeast Atlantic seawater to a chemical Dispersant, whether in the presence/absence of crude oil, the Dispersant stimulates the production of significant quantities of EPS that we posit serves as a key building block in the formation of MOS. This response is likely conferred via de novo synthesis of EPS by natural communities of bacteria. We also describe the formation of marine Dispersant snow (MDS) as a product of adding chemical Dispersants to seawater. Differential staining confirmed that MDS, like MOS, is composed of glycoprotein, though MDS is more protein rich. Using barcoded-amplicon Illumina MiSeq sequencing, we analyzed, for the first time, the bacterial communities associated with MDS and report that their diversity is not significantly dissimilar to those associated with MOS aggregates. Our findings emphasize the need to conduct further work on the effects of Dispersants when applied to oil spills at sea, particularly at different sites, and to determine how the product of this (i.e., MOS and MDS) affects the biodegradation of the oil
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Image_1_Chemical Dispersant Enhances Microbial Exopolymer (EPS) Production and Formation of Marine Oil/Dispersant Snow in Surface Waters of the Subarctic Northeast Atlantic.PNG
2019Co-Authors: Laura Duran Suja, Xindi Chen, Stephen Summers, David M Paterson, Tony GutierrezAbstract:A notable feature of the Deepwater Horizon oil spill was the unprecedented formation of marine oil snow (MOS) that was observed in large quantities floating on the sea surface and that subsequently sedimented to the seafloor. Whilst the physical and chemical processes involved in MOS formation remain unclear, some studies have shown that extracellular polymeric substances (EPS) play a role in this process. Here, we report that during exposure of subarctic northeast Atlantic seawater to a chemical Dispersant, whether in the presence/absence of crude oil, the Dispersant stimulates the production of significant quantities of EPS that we posit serves as a key building block in the formation of MOS. This response is likely conferred via de novo synthesis of EPS by natural communities of bacteria. We also describe the formation of marine Dispersant snow (MDS) as a product of adding chemical Dispersants to seawater. Differential staining confirmed that MDS, like MOS, is composed of glycoprotein, though MDS is more protein rich. Using barcoded-amplicon Illumina MiSeq sequencing, we analyzed, for the first time, the bacterial communities associated with MDS and report that their diversity is not significantly dissimilar to those associated with MOS aggregates. Our findings emphasize the need to conduct further work on the effects of Dispersants when applied to oil spills at sea, particularly at different sites, and to determine how the product of this (i.e., MOS and MDS) affects the biodegradation of the oil.
Xindi Chen - One of the best experts on this subject based on the ideXlab platform.
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chemical Dispersant enhances microbial exopolymer eps production and formation of marine oil Dispersant snow in surface waters of the subarctic northeast atlantic
Frontiers in Microbiology, 2019Co-Authors: Laura Duran Suja, Xindi Chen, Stephen Summers, David M Paterson, Tony GutierrezAbstract:A notable feature of the Deepwater Horizon oil spill was the unprecedented formation of marine oil snow (MOS) that was observed in large quantities floating on the sea surface and that subsequently sedimented to the seafloor. Whilst the physical and chemical processes involved in MOS formation remain unclear, some studies have shown that extracellular polymeric substances (EPS) play a role in this process. Here, we report that during exposure of subarctic northeast Atlantic seawater to a chemical Dispersant, whether in the presence/absence of crude oil, the Dispersant stimulates the production of significant quantities of EPS that we posit serves as a key building block in the formation of MOS. This response is likely conferred via de novo synthesis of EPS by natural communities of bacteria. We also describe the formation of marine Dispersant snow (MDS) as a product of adding chemical Dispersants to seawater. Differential staining confirmed that MDS, like MOS, is composed of glycoprotein, though MDS is more protein rich. Using barcoded-amplicon Illumina MiSeq sequencing, we analyzed, for the first time, the bacterial communities associated with MDS and report that their diversity is not significantly dissimilar to those associated with MOS aggregates. Our findings emphasize the need to conduct further work on the effects of Dispersants when applied to oil spills at sea, particularly at different sites, and to determine how the product of this (i.e., MOS and MDS) affects the biodegradation of the oil.
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Chemical Dispersant Enhances Microbial Exopolymer (EPS) Production and Formation of Marine Oil/Dispersant Snow in Surface Waters of the Subarctic Northeast Atlantic
Frontiers Media S.A., 2019Co-Authors: Laura Duran Suja, Xindi Chen, Stephen Summers, David M Paterson, Tony GutierrezAbstract:A notable feature of the Deepwater Horizon oil spill was the unprecedented formation of marine oil snow (MOS) that was observed in large quantities floating on the sea surface and that subsequently sedimented to the seafloor. Whilst the physical and chemical processes involved in MOS formation remain unclear, some studies have shown that extracellular polymeric substances (EPS) play a role in this process. Here, we report that during exposure of subarctic northeast Atlantic seawater to a chemical Dispersant, whether in the presence/absence of crude oil, the Dispersant stimulates the production of significant quantities of EPS that we posit serves as a key building block in the formation of MOS. This response is likely conferred via de novo synthesis of EPS by natural communities of bacteria. We also describe the formation of marine Dispersant snow (MDS) as a product of adding chemical Dispersants to seawater. Differential staining confirmed that MDS, like MOS, is composed of glycoprotein, though MDS is more protein rich. Using barcoded-amplicon Illumina MiSeq sequencing, we analyzed, for the first time, the bacterial communities associated with MDS and report that their diversity is not significantly dissimilar to those associated with MOS aggregates. Our findings emphasize the need to conduct further work on the effects of Dispersants when applied to oil spills at sea, particularly at different sites, and to determine how the product of this (i.e., MOS and MDS) affects the biodegradation of the oil
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Image_1_Chemical Dispersant Enhances Microbial Exopolymer (EPS) Production and Formation of Marine Oil/Dispersant Snow in Surface Waters of the Subarctic Northeast Atlantic.PNG
2019Co-Authors: Laura Duran Suja, Xindi Chen, Stephen Summers, David M Paterson, Tony GutierrezAbstract:A notable feature of the Deepwater Horizon oil spill was the unprecedented formation of marine oil snow (MOS) that was observed in large quantities floating on the sea surface and that subsequently sedimented to the seafloor. Whilst the physical and chemical processes involved in MOS formation remain unclear, some studies have shown that extracellular polymeric substances (EPS) play a role in this process. Here, we report that during exposure of subarctic northeast Atlantic seawater to a chemical Dispersant, whether in the presence/absence of crude oil, the Dispersant stimulates the production of significant quantities of EPS that we posit serves as a key building block in the formation of MOS. This response is likely conferred via de novo synthesis of EPS by natural communities of bacteria. We also describe the formation of marine Dispersant snow (MDS) as a product of adding chemical Dispersants to seawater. Differential staining confirmed that MDS, like MOS, is composed of glycoprotein, though MDS is more protein rich. Using barcoded-amplicon Illumina MiSeq sequencing, we analyzed, for the first time, the bacterial communities associated with MDS and report that their diversity is not significantly dissimilar to those associated with MOS aggregates. Our findings emphasize the need to conduct further work on the effects of Dispersants when applied to oil spills at sea, particularly at different sites, and to determine how the product of this (i.e., MOS and MDS) affects the biodegradation of the oil.
Sara Kleindienst - One of the best experts on this subject based on the ideXlab platform.
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biodegradation of crude oil and Dispersants in deep seawater from the gulf of mexico insights from ultra high resolution mass spectrometry
Deep-sea Research Part Ii-topical Studies in Oceanography, 2016Co-Authors: Sara Kleindienst, Michael Seidel, Samantha B Joye, Thorsten Dittmar, Patricia M MedeirosAbstract:Abstract During the 2010 Deepwater Horizon oil spill in the Gulf of Mexico, three million liters of chemical Dispersants (Corexit 9500 and 9527) were directly applied at the discharging wellhead at 1500 m water depth. Such a deep-water large-scale application was unprecedented and the effect of Dispersants on oil biodegradation is not yet completely understood. The present study explores the biodegradation of oil, Dispersant, dispersed oil or dispersed oil and nutrients at the molecular level using ultra-high resolution Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR–MS) following a laboratory experiment with Gulf deep water. Oil-derived molecular formulae exhibited a specific molecular fingerprint and were mainly observed in the mass range
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reply to prince et al ability of chemical Dispersants to reduce oil spill impacts remains unclear
Proceedings of the National Academy of Sciences of the United States of America, 2016Co-Authors: Sara Kleindienst, Michael Seidel, Kai Ziervogel, Sharon L Grim, Kathy M Loftis, Sarah Harrison, Sairah Y Malkin, Matthew J Perkins, Jennifer A Field, Mitchell L SoginAbstract:Chemical Dispersants are applied to oil-contaminated areas as a primary response to oceanic oil spills. The impacts of Dispersants on microbial community composition and activity, particularly hydrocarbon turnover, are debated. Kleindienst et al. (1) demonstrated that Corexit 9500, a Dispersant, can suppress the activity of oil-degrading microorganisms. Chemically enhanced water-accommodated fractions (CEWAFs) were used for these experiments because the deepwater plume that formed following the Deepwater Horizon (DWH) blowout consisted of the water-accommodated fraction: Roughly half of the discharged oil, along with Dispersants applied at the wellhead, was entrained in the deepwater plume (2). Using CEWAFs assured an appropriate simulation of the DWH plume chemistry. Prince et al. (3) claim that the method used to produce CEWAFs would leave … [↵][1]5To whom correspondence should be addressed. Email: mjoye{at}uga.edu. [1]: #xref-corresp-1-1
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chemical Dispersants can suppress the activity of natural oil degrading microorganisms
Proceedings of the National Academy of Sciences of the United States of America, 2015Co-Authors: Sara Kleindienst, Michael Seidel, Kai Ziervogel, Sharon L Grim, Kathy M Loftis, Sarah Harrison, Sairah Y Malkin, Matthew J Perkins, Jennifer A Field, Mitchell L SoginAbstract:During the Deepwater Horizon oil well blowout in the Gulf of Mexico, the application of 7 million liters of chemical Dispersants aimed to stimulate microbial crude oil degradation by increasing the bioavailability of oil compounds. However, the effects of Dispersants on oil biodegradation rates are debated. In laboratory experiments, we simulated environmental conditions comparable to the hydrocarbon-rich, 1,100 m deep plume that formed during the Deepwater Horizon discharge. The presence of Dispersant significantly altered the microbial community composition through selection for potential Dispersant-degrading Colwellia, which also bloomed in situ in Gulf deep waters during the discharge. In contrast, oil addition to deepwater samples in the absence of Dispersant stimulated growth of natural hydrocarbon-degrading Marinobacter. In these deepwater microcosm experiments, Dispersants did not enhance heterotrophic microbial activity or hydrocarbon oxidation rates. An experiment with surface seawater from an anthropogenically derived oil slick corroborated the deepwater microcosm results as inhibition of hydrocarbon turnover was observed in the presence of Dispersants, suggesting that the microcosm findings are broadly applicable across marine habitats. Extrapolating this comprehensive dataset to real world scenarios questions whether Dispersants stimulate microbial oil degradation in deep ocean waters and instead highlights that Dispersants can exert a negative effect on microbial hydrocarbon degradation rates.
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using Dispersants after oil spills impacts on the composition and activity of microbial communities
Nature Reviews Microbiology, 2015Co-Authors: Sara Kleindienst, John H Paul, Samantha B JoyeAbstract:Dispersants are globally and routinely applied as an emergency response to oil spills in marine ecosystems with the goal of chemically enhancing the dissolution of oil into water, which is assumed to stimulate microbially mediated oil biodegradation. However, little is known about how Dispersants affect the composition of microbial communities or their biodegradation activities. The published findings are controversial, probably owing to variations in laboratory methods, the selected model organisms and the chemistry of different Dispersant-oil mixtures. Here, we argue that an in-depth assessment of the impacts of Dispersants on microorganisms is needed to evaluate the planning and use of Dispersants during future responses to oil spills.
Sibani Lisa Biswal - One of the best experts on this subject based on the ideXlab platform.
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characterizing asphaltene deposition in the presence of chemical Dispersants in porous media micromodels
Energy & Fuels, 2017Co-Authors: Peng He, Nevin Thunduvila Mathew, Yap Yit Fatt, J C Chai, Afshin Goharzadeh, Mohammad Tavakkoli, Francisco M Vargas, Sibani Lisa BiswalAbstract:Asphaltenes are components in crude oil known to deposit and interrupt flows in critical regions during oil production, such as the wellbore and transportation pipelines. Chemical Dispersants are commonly used to disperse asphaltenes into smaller agglomerates or increase asphaltene stability in solution with the goal of preventing deposition. However, in many cases, these chemical Dispersants fail in the field or even worsen the deposition problems in the wellbores. Further understanding of the mechanisms by which Dispersants alter asphaltene deposition under dynamic flowing conditions is needed to better understand flow assurance problems. Here, we describe the use of porous media microfluidic devices to evaluate how chemical Dispersants change asphaltene deposition. Four commercially used alkylphenol model chemical Dispersants are tested with model oils flowing through porous media, and the resulting deposition kinetics are visualized at both the matrix scale and pore scale. Interestingly, initial asphaltene deposition worsens in the presence of the tested Dispersants, but the mechanism by which plugging and permeability reduction in the porous media varies. The velocity profiles near the deposit are analyzed to further investigate how shear forces affect asphaltene deposition. The deposition tendency is also related to the intermolecular interactions governing the asphaltene–Dispersant systems. Furthermore, the model system is extended to a real case. The use of porous media microfluidic devices offers a unique platform to develop and design effective chemical Dispersants for flow assurance problems.
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Characterizing Asphaltene Deposition in the Presence of Chemical Dispersants in Porous Media Micromodels
2017Co-Authors: Yu-jiun Lin, Nevin Thunduvila Mathew, Yap Yit Fatt, J C Chai, Afshin Goharzadeh, Mohammad Tavakkoli, Francisco M Vargas, Sibani Lisa BiswalAbstract:Asphaltenes are components in crude oil known to deposit and interrupt flows in critical regions during oil production, such as the wellbore and transportation pipelines. Chemical Dispersants are commonly used to disperse asphaltenes into smaller agglomerates or increase asphaltene stability in solution with the goal of preventing deposition. However, in many cases, these chemical Dispersants fail in the field or even worsen the deposition problems in the wellbores. Further understanding of the mechanisms by which Dispersants alter asphaltene deposition under dynamic flowing conditions is needed to better understand flow assurance problems. Here, we describe the use of porous media microfluidic devices to evaluate how chemical Dispersants change asphaltene deposition. Four commercially used alkylphenol model chemical Dispersants are tested with model oils flowing through porous media, and the resulting deposition kinetics are visualized at both the matrix scale and pore scale. Interestingly, initial asphaltene deposition worsens in the presence of the tested Dispersants, but the mechanism by which plugging and permeability reduction in the porous media varies. The velocity profiles near the deposit are analyzed to further investigate how shear forces affect asphaltene deposition. The deposition tendency is also related to the intermolecular interactions governing the asphaltene–Dispersant systems. Furthermore, the model system is extended to a real case. The use of porous media microfluidic devices offers a unique platform to develop and design effective chemical Dispersants for flow assurance problems
Kenneth Lee - One of the best experts on this subject based on the ideXlab platform.
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impact of mixing time and energy on the dispersion effectiveness and droplets size of oil
Chemosphere, 2017Co-Authors: Zhong Pan, Michel C. Boufadel, Thomas King, Robyn N Conmy, Lin Zhao, Brian Robinson, Kenneth LeeAbstract:Abstract The effects of mixing time and energy on Alaska Northern Slope (ANS) and diluted bitumen Cold Lake Blend (CLB) were investigated using EPA baffled flask test. Dispersion effectiveness and droplet size distribution were measured after 5–120 min. A modeling method to predict the mean droplet size was introduced for the first time to tentatively elucidate the droplet size breakup mechanism. The ANS dispersion effectiveness greatly increased with Dispersant and mixing energy. However, little CLB dispersion was noted at small energy input (e = 0.02 Watt/kg). With Dispersant, the ANS droplet size distribution reached quasi-equilibrium within 10 min, but that of CLB seems to reach quasi-equilibrium after 120 min. Dispersants are assumed ineffective on high viscosity oils because Dispersants do not penetrate them. We provide an alternative explanation based on the elongation time of the droplets and its residence in high intensity zones. When mixing energy is small, CLB did not disperse after 120 min, long enough to allow the surfactant penetration. Our findings suggest that Dispersants may disperse high viscosity oils at a rougher sea state and a longer time. The latter could determine how far offshore one can intervene for effective responses to a high viscosity oil spill offshore.
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wave tank studies on Dispersant effectiveness as a function of energy dissipation rate and particle size distribution
2009Co-Authors: Kenneth Lee, Michel C. BoufadelAbstract:The use of chemical Dispersants can be an effective means to combat oil spills at sea. There has been renewed interest in the use of chemical Dispersants due to escalated oil spill incidents, logistical constraints of traditional spill response options, and the development of new generation, low-toxicity, high efficiency Dispersant formulations for potential use on oils covering a greater viscosity range. For the assessment of chemical Dispersant effectiveness under realistic sea states, test protocols are required to produce hydrodynamic conditions close to the mixing, transport and dilution effects found in the natural environment. To meet this requirement, a wave tank has been designed and constructed at the Bedford Institute of Oceanography (BIO) to evaluate chemical Dispersant effectiveness under different wave conditions with energy levels ranging from regular non-breaking waves to plunging breakers. The hydrodynamics of these wave conditions were characterized using an autocorrelation function method applied to in-situ velocity measurements. Quantification of oil Dispersant effectiveness was based on observed changes in dispersed oil concentrations and oil-droplet size distribution using a laser in-situ scattering and transmissometry particle size analyzer. Evaluation of chemical Dispersant effectiveness in a batch mode established quantitative relationships between Dispersant effectiveness and energy dissipation rate under a variety of simulated wave conditions. The results indicated that 53% to 90% of the test crude oils have been dispersed in the presence of chemical Dispersants and only 10% to 20% were dispersed under control conditions in the absence of chemical Dispersant. The characterization of the in-situ dispersed oil droplet size distributions indicated that the physical dispersion generated monomodal lognormal oil droplet size distributions of larger median diameters, whereas chemical dispersion produced bior tri-modal lognormal oil droplet size distributions of smaller median diameters over a wider range. The wave tank in flow-through mode simulating waveand current-driven hydrodynamic conditions revealed that nearly 8 % to19 % of the test crude oils were dispersed and diluted under regular wave and breaking wave conditions, respectively, in the absence of Dispersants. In the presence of Dispersants, about 21% to 36% of the crude oils were dispersed and diluted under regular waves, and 42% to 62% under breaking waves. Consistently, physical dispersion under regular waves produced large oil droplets, whereas chemical dispersion under breaking waves created small droplets. These data on the effectiveness of Dispersants as a function of sea state are significant contributions to the development of improved predictive models on Dispersant effectiveness and better operational guidelines for Dispersant use. Results of our experiential studies using the wave tank system have advanced our mechanistic understanding of Dispersant effectiveness under ambient field conditions. The research has shown that use of Dispersants in deep water environments under moderately energetic wave conditions is a promising countermeasure technology for driving floating oil into the water column. Chemical Dispersant Corexit 9500 is effective in all low, moderate and high energy test conditions, whereas SPC 1000 can also be very useful in moderate to higher energy conditions. Effective dispersion of oil to achieve small droplet formation is dependent on wave energy and the presence of a chemical Dispersant. If either of these two factors is missing, dispersion can only take place in very high energy sea states. Use of chemical Dispersants drastically reduces the time required for thorough dispersion of oil into small oil droplets in the water column to take place in comparison to natural dispersion. When the window of opportunity for oil spill response is narrow (i.e. rapid remediation is critical due to proximity to environmentally sensitive areas), a quick and effective response such as what can be achieved using Dispersants may be deemed necessary even under high energy conditions because of their ability to through accelerate the process and efficacy of oil dispersion into the water column and to facilitate oil biodegradation.
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OIL DROPLET SIZE DISTRIBUTION AS A FUNCTION OF ENERGY DISSIPATION RATE IN AN EXPERIMENTAL WAVE TANK
International Oil Spill Conference Proceedings, 2008Co-Authors: Kenneth Lee, Michel C. Boufadel, Thomas King, Albert D. VenosaAbstract:ABSTRACT The U.S. National Research Council (NRC) Committee on Understanding Oil Spill Dispersants: Efficacy and Effects (2005) identified two factors that require further investigation in chemical oil Dispersant efficacy studies: 1) quantification of mixing energy at sea as energy dissipation rate and 2) dispersed particle size distribution. To fully evaluate the significance of these factors, a wave tank facility was designed and constructed to conduct controlled oil dispersion studies. A factorial experimental design was used to study the Dispersant effectiveness as a function of energy dissipation rate for two oils and two Dispersants under three different wave conditions, namely regular non-breaking waves, spilling breakers, and plunging breakers. The oils tested were weathered MESA and fresh ANS crude. The Dispersants tested were Corexit 9500 and SPC 1000 plus water for no-Dispersant control. The wave tank surface energy dissipatation rates of the three waves were determined to be 0.005, 0.1, and 1 ...
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assessment of chemical Dispersant effectiveness in a wave tank under regular non breaking and breaking wave conditions
Marine Pollution Bulletin, 2008Co-Authors: Kenneth Lee, Michel C. Boufadel, Thomas King, Albert D. VenosaAbstract:Current chemical Dispersant effectiveness tests for product selection are commonly performed with bench-scale testing apparatus. However, for the assessment of oil Dispersant effectiveness under real sea state conditions, test protocols are required to have hydrodynamic conditions closer to the natural environment, including transport and dilution effects. To achieve this goal, Fisheries and Oceans Canada and the US Environmental Protection Agency (EPA) designed and constructed a wave tank system to study chemical Dispersant effectiveness under controlled mixing energy conditions (regular non-breaking, spilling breaking, and plunging breaking waves). Quantification of oil Dispersant effectiveness was based on observed changes in dispersed oil concentrations and oil-droplet size distribution. The study results quantitatively demonstrated that total dispersed oil concentration and breakup kinetics of oil droplets in the water column were strongly dependent on the presence of chemical Dispersants and the influence of breaking waves. These data on the effectiveness of Dispersants as a function of sea state will have significant implications in the drafting of future operational guidelines for Dispersant use at sea.