The Experts below are selected from a list of 297 Experts worldwide ranked by ideXlab platform
Aswani Volety - One of the best experts on this subject based on the ideXlab platform.
-
the sensitivity of the deepsea species northern shrimp pandalus borealis and the cold water coral lophelia pertusa to Oil associated aromatic compounds dispersant and alaskan north slope crude Oil
Marine Pollution Bulletin, 2020Co-Authors: Jenny Bytingsvik, Thomas F Parkerton, Julien Guyomarch, Luca Tassara, Stephane Lefloch, Ray W Arnold, Susanne M Brander, Aswani VoletyAbstract:Abstract This study investigated the sensitivity of two deepsea species using mortality of northern shrimp (Pandalus borealis) and polyp activity of stony coral (Lophelia pertusa) to dispersant, Corexit 9500 and aromatic hydrocarbons (toluene, 2-methylnaphthalene, phenanthrene) in 96-h tests. Resulting hydrocarbon Toxicity data were fit to the Target Lipid Model to generate predictive models and determine species sensitivity. Toxicity of chemically enhanced water accommodated fractions of Alaskan North Slope crude Oil (ANS-Oil) was also investigated with shrimp using nominal loading, total petroleum hydrocarbons and biomimetic extraction (BE) as Oil exposure metrics. Coral were more sensitive to dispersant than shrimp while similar sensitivity was observed for hydrocarbons. Study and literature findings indicate deepsea species exhibit acute sensitivities to dispersant, hydrocarbons and Oil that are comparable to pelagic species. Results support use of passive sampling methods to quantify dissolved Oil for interpreting Oil Toxicity tests and suggest models for predicting time-dependence of Toxicity warrant re-evaluation.
Laura R. Jarboe - One of the best experts on this subject based on the ideXlab platform.
-
Microalgae fermentation of acetic acid‐rich pyrolytic bio‐Oil: Reducing bio‐Oil Toxicity by alkali treatment
Environmental Progress, 2013Co-Authors: Xuefei Zhao, Marjorie Rover, Robert C. Brown, Laura R. JarboeAbstract:Bio-Oil derived from fast pyrolysis of lignocellulosic biomass contains various substrates that can be fermented to fuels and chemicals. The goal of this research was to utilize an acetic acid-rich fraction of bio-Oil for the growth and lipid production by microalga Chlamydomonas reinhardtii. As toxic compounds are contained in the bio-Oil, the algae cannot survive in medium containing this bio-Oil fraction even at a low level (0.05 wt %). An alkali-based treatment with sodium hydroxide was used to reduce the Toxicity and enhance its fermentability by microalgae. It was found that treating the acetic acid-rich bio-Oil fraction by adjusting pH to 10 greatly improved the algal growth. The algae can thrive in medium containing 4 wt % alkali-treated bio-Oil fraction. When using a metabolic-evolved strain with high level of Toxicity tolerance, the algae were even capable of growing in medium containing 5.5 wt % bio-Oil fraction, which replaced 100% of the acetic acid in the medium. The algal biomass grown in medium containing alkali-treated bio-Oil fraction exhibited fatty acid profiles similar to the culture grown in pure acetic acid, but with a lower total fatty acid content. but the total fatty acid content (∼10% DW) was lower than that of the control (∼20% DW).The benefit of alkali treatment for enhancing algal growth was confirmed to be due to the removal of toxic compounds such as furfural, acetol, phenolics, and 5-hydroxymethylfurfural (HMF). Collectively, the results showed that fast pyrolysis-microalgal fermentation is a viable approach for producing lipid from lignocellulosic biomass. Alkali-based treatment is an effective method for reducing bio-Oil Toxicity, and thereby, greatly enhancing the algae fermentability of bio-Oil. © 2013 American Institute of Chemical Engineers Environ Prog, 32: 955–961, 2013
-
utilization of acetic acid rich pyrolytic bio Oil by microalga chlamydomonas reinhardtii reducing bio Oil Toxicity and enhancing algal Toxicity tolerance
Bioresource Technology, 2013Co-Authors: Yi Liang, Xuefei Zhao, Marjorie Rover, Robert C. Brown, Patrick A Johnston, Laura R. JarboeAbstract:This work was to utilize acetic acid contained in bio-Oil for growth and lipid production of the microalga Chlamydomonas reinhardtii. The acetic acid-rich bio-Oil fraction derived from fast pyrolysis of softwood contained 26% (w/w) acetic acid, formic acid, methanol, furfural, acetol, and phenolics as identified compounds, and 13% (w/w) unidentified compounds. Among those identified compounds, phenolics were most inhibitory to algal growth, followed by furfural and acetol. To enhance the fermentability of the bio-Oil fraction, activated carbon was used to reduce the Toxicity of the bio-Oil, while metabolic evolution was used to enhance the Toxicity tolerance of the microalgae. Combining activated carbon treatment and using evolved algal strain resulted in significant algal growth improvement. The results collectively showed that fast pyrolysis-fermentation process was a viable approach for converting biomass into fuels and chemicals.
Knut Erik Tollefsen - One of the best experts on this subject based on the ideXlab platform.
-
chemical and toxicological characterization of an unresolved complex mixture rich biodegraded crude Oil
Environmental Toxicology and Chemistry, 2009Co-Authors: Alf G Melbye, Steven J Rowland, Odd Gunnar Brakstad, Jorunn Nerbo Hokstad, Inger Katharina Gregersen, Bjorn Henrik Hansen, Andy M Booth, Knut Erik TollefsenAbstract:Chemical and toxicological characterization of unresolved complex mixtures in the water-soluble fraction of an artificially weathered Norwegian Sea crude Oil was determined by a combination of chemical analysis and Toxicity testing in fish in vitro bioassays. The water-soluble fraction of the crude Oil was separated into 14 increasingly polar fractions by preparative high-pressure liquid chromatography. The in vitro Toxicity (7-ethoxyresorufin
Toxicity was one of the most polar fractions, accounting gravimetrically for more than 70% of the organic material in the water-soluble fraction and dominated by an unresolved complex mixture. Chemical analysis by gas chromatography-mass spectrometry and comprehensive two-dimensional gas chromatography—time of flight—mass spectrometry identified a large number of cyclic and aromatic sulfoxide compounds and low amounts of benzothiophenes (<0.1% of total mass) in this fraction. Commonly monitored toxic components of crude Oil (e.g., naphthalenes, polycyclic aromatic hydrocarbons, and alkylated phenols) eluted in less polar fractions, characterized by somewhat lower Toxicity. Normalization of in vitro responses to the mass in each fraction demonstrated a more even distribution of Toxicity, indicating that Toxicity in the individual fractions was related to the amount of material present. Although polar and nonpolar compounds contribute additively to crude Oil Toxicity, the water-soluble fraction was dominated by polar compounds because of their high aqueous solubility and the high Oil—water loading. Under these conditions, the polar unresolved complex mixture—rich fraction might account for a large portion of crude Oil Toxicity because of its high abundance in the water-soluble fraction.
Andy M Booth - One of the best experts on this subject based on the ideXlab platform.
-
chemical and toxicological characterization of an unresolved complex mixture rich biodegraded crude Oil
Environmental Toxicology and Chemistry, 2009Co-Authors: Alf G Melbye, Steven J Rowland, Odd Gunnar Brakstad, Jorunn Nerbo Hokstad, Inger Katharina Gregersen, Bjorn Henrik Hansen, Andy M Booth, Knut Erik TollefsenAbstract:Chemical and toxicological characterization of unresolved complex mixtures in the water-soluble fraction of an artificially weathered Norwegian Sea crude Oil was determined by a combination of chemical analysis and Toxicity testing in fish in vitro bioassays. The water-soluble fraction of the crude Oil was separated into 14 increasingly polar fractions by preparative high-pressure liquid chromatography. The in vitro Toxicity (7-ethoxyresorufin
Toxicity was one of the most polar fractions, accounting gravimetrically for more than 70% of the organic material in the water-soluble fraction and dominated by an unresolved complex mixture. Chemical analysis by gas chromatography-mass spectrometry and comprehensive two-dimensional gas chromatography—time of flight—mass spectrometry identified a large number of cyclic and aromatic sulfoxide compounds and low amounts of benzothiophenes (<0.1% of total mass) in this fraction. Commonly monitored toxic components of crude Oil (e.g., naphthalenes, polycyclic aromatic hydrocarbons, and alkylated phenols) eluted in less polar fractions, characterized by somewhat lower Toxicity. Normalization of in vitro responses to the mass in each fraction demonstrated a more even distribution of Toxicity, indicating that Toxicity in the individual fractions was related to the amount of material present. Although polar and nonpolar compounds contribute additively to crude Oil Toxicity, the water-soluble fraction was dominated by polar compounds because of their high aqueous solubility and the high Oil—water loading. Under these conditions, the polar unresolved complex mixture—rich fraction might account for a large portion of crude Oil Toxicity because of its high abundance in the water-soluble fraction.
Thomas F Parkerton - One of the best experts on this subject based on the ideXlab platform.
-
the sensitivity of the deepsea species northern shrimp pandalus borealis and the cold water coral lophelia pertusa to Oil associated aromatic compounds dispersant and alaskan north slope crude Oil
Marine Pollution Bulletin, 2020Co-Authors: Jenny Bytingsvik, Thomas F Parkerton, Julien Guyomarch, Luca Tassara, Stephane Lefloch, Ray W Arnold, Susanne M Brander, Aswani VoletyAbstract:Abstract This study investigated the sensitivity of two deepsea species using mortality of northern shrimp (Pandalus borealis) and polyp activity of stony coral (Lophelia pertusa) to dispersant, Corexit 9500 and aromatic hydrocarbons (toluene, 2-methylnaphthalene, phenanthrene) in 96-h tests. Resulting hydrocarbon Toxicity data were fit to the Target Lipid Model to generate predictive models and determine species sensitivity. Toxicity of chemically enhanced water accommodated fractions of Alaskan North Slope crude Oil (ANS-Oil) was also investigated with shrimp using nominal loading, total petroleum hydrocarbons and biomimetic extraction (BE) as Oil exposure metrics. Coral were more sensitive to dispersant than shrimp while similar sensitivity was observed for hydrocarbons. Study and literature findings indicate deepsea species exhibit acute sensitivities to dispersant, hydrocarbons and Oil that are comparable to pelagic species. Results support use of passive sampling methods to quantify dissolved Oil for interpreting Oil Toxicity tests and suggest models for predicting time-dependence of Toxicity warrant re-evaluation.
-
guidance for improving comparability and relevance of Oil Toxicity tests
Marine Pollution Bulletin, 2015Co-Authors: Aaron D Redman, Thomas F ParkertonAbstract:The complex nature and limited aqueous solubility of petroleum substances pose challenges for consistently characterizing exposures in aquatic life hazard assessments. This paper reviews important considerations for the design, conduct and interpretation of laboratory Toxicity tests with physically and chemically dispersed Oils based on an understanding of the behavior and Toxicity of the hydrocarbons that comprise these substances. Guiding principles are provided that emphasize the critical need to understand and, when possible, characterize dissolved hydrocarbon exposures that dictate observed Toxicity in these tests. These principles provide a consistent framework for interpreting Toxicity studies performed using different substances and test methods by allowing varying dissolved exposures to be expressed in terms of a common metric based on toxic units (TUs). The use of passive sampling methods is also advocated since such analyses provide an analytical surrogate for TUs. The proposed guidance is translated into a series of questions that can be used in evaluating existing data and in guiding design of future studies. Application of these questions to a number of recent publications indicates such considerations are often ignored, thus perpetuating the difficulty of interpreting and comparing results between studies and limiting data use in objective hazard assessment. Greater attention to these principles will increase the comparability and utility of Oil Toxicity data in decision-making.
-
Use of passive samplers for improving Oil Toxicity and spill effects assessment.
Marine Pollution Bulletin, 2014Co-Authors: Daniel J. Letinski, Aaron D Redman, Thomas F Parkerton, Gail E. Bragin, Ryan Manning, Eric Febbo, David Palandro, Tim NedwedAbstract:Methods that quantify dissolved hydrocarbons are needed to link Oil exposures to Toxicity. Solid phase microextraction (SPME) fibers can serve this purpose. If fibers are equilibrated with Oiled water, dissolved hydrocarbons partition to and are concentrated on the fiber. The absorbed concentration (Cpolymer) can be quantified by thermal desorption using GC/FID. Further, given that the site of toxic action is hypothesized as biota lipid and partitioning of hydrocarbons to lipid and fibers is well correlated, Cpolymer is hypothesized to be a surrogate for Toxicity prediction. To test this method, Toxicity data for physically and chemically dispersed Oils were generated for shrimp, Americamysis bahia, and compared to test exposures characterized by Cpolymer. Results indicated that Cpolymer reliably predicted Toxicity across Oils and dispersions. To illustrate field application, SPME results are reported for Oil spills at the Ohmsett facility. SPME fibers provide a practical tool to improve characterization of Oil exposures and predict effects in future lab and field studies.
-
Guidance for improving comparability and relevance of dispersed Oil Toxicity tests
International Oil Spill Conference Proceedings, 2014Co-Authors: Aaron D Redman, Thomas F ParkertonAbstract:The complex nature, variable composition and limited aqueous solubility of crude Oil and related petroleum products poses challenges for evaluating the aquatic Toxicity of these substances. While considerable research has been performed to understand the effects of physically and chemically dispersed Oils to aquatic organisms, differences in design and conduct of aquatic Toxicity studies often makes results impossible to compare and correctly apply in decision-making. A review of past approaches for generating and characterizing Oil exposures in Toxicity tests in the absence and presence of chemical dispersants based on the commonly used water accommodated fraction (WAF) procedure is discussed. Differences in the multicomponent dissolution behavior and resulting exposure concentrations of dissolved hydrocarbons in WAFs obtained from different test procedures based on nominal Oil loadings or WAF dilutions are illustrated using several case studies. To provide a consistent framework for interpreting toxicit...
