The Experts below are selected from a list of 117177 Experts worldwide ranked by ideXlab platform
Jason R Rohr - One of the best experts on this subject based on the ideXlab platform.
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community responses to Contaminants using basic ecological principles to predict ecotoxicological effects
Environmental Toxicology and Chemistry, 2009Co-Authors: William H. Clements, Jason R RohrAbstract:Community ecotoxicology is defined as the study of the effects of Contaminants on patterns of species abundance, diversity, community composition, and species interactions. Recent discoveries that species diversity is positively associated with ecosystem stability, recovery, and services have made a community-level perspective on ecotoxicology more important than ever. Community ecotoxicology must explicitly consider both present and impending global change and shift from a purely descriptive to a more predictive science. Greater consideration of the ecological factors and threshold responses that determine community resistance and resilience should improve our ability to predict how and when communities will respond to, and recover from, xenobiotics. A better understanding of pollution-induced community tolerance, and of the costs of this tolerance, should facilitate identifying Contaminant- impacted communities, thus forecasting the ecological consequences of Contaminant exposure and determining the restoration effectiveness. Given the vast complexity of community ecotoxicology, simplifying assumptions, such as the possibility that the approximately 100,000 registered chemicals could be reduced to a more manageable number of Contaminant classes with similar modes of action, must be identified and validated. In addition to providing a framework for predicting Contaminant fate and effects, food-web ecology can help to identify communities that are sensitive to Contaminants, Contaminants that are particularly insidious to communities, and species that are crucial for transmitting adverse effects across trophic levels. Integration of basic ecological principles into the design and implementation of ecotoxicological research is essential for predicting Contaminant effects within the context of rapidly changing, global environmental conditions. Keywords—Community ecotoxicology Contaminant transport Global change Indirect effects Resistance/resilience
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community responses to Contaminants using basic ecological principles to predict ecotoxicological effects
Environmental Toxicology and Chemistry, 2009Co-Authors: William H. Clements, Jason R RohrAbstract:Community ecotoxicology is defined as the study of the effects of Contaminants on patterns of species abundance, diversity, community composition, and species interactions. Recent discoveries that species diversity is positively associated with ecosystem stability, recovery, and services have made a community-level perspective on ecotoxicology more important than ever. Community ecotoxicology must explicitly consider both present and impending global change and shift from a purely descriptive to a more predictive science. Greater consideration of the ecological factors and threshold responses that determine community resistance and resilience should improve our ability to predict how and when communities will respond to, and recover from, xenobiotics. A better understanding of pollution-induced community tolerance, and of the costs of this tolerance, should facilitate identifying Contaminant-impacted communities, thus forecasting the ecological consequences of Contaminant exposure and determining the restoration effectiveness. Given the vast complexity of community ecotoxicology, simplifying assumptions, such as the possibility that the approximately 100,000 registered chemicals could be reduced to a more manageable number of Contaminant classes with similar modes of action, must be identified and validated. In addition to providing a framework for predicting Contaminant fate and effects, food-web ecology can help to identify communities that are sensitive to Contaminants, Contaminants that are particularly insidious to communities, and species that are crucial for transmitting adverse effects across trophic levels. Integration of basic ecological principles into the design and implementation of ecotoxicological research is essential for predicting Contaminant effects within the context of rapidly changing, global environmental conditions.
Yavuz M Corapcioglu - One of the best experts on this subject based on the ideXlab platform.
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effect of dissolved organic matter and bacteria on Contaminant transport in riverbank filtration
Journal of Contaminant Hydrology, 2003Co-Authors: Song-bae Kim, Yavuz M Corapcioglu, Dong Ju KimAbstract:A mathematical model for the transport of hydrophobic organic Contaminants in an aquifer under simplistic riverbank filtration conditions is developed. The model considers a situation where Contaminants are present together with dissolved organic matter (DOM) and bacteria. The aquifer is conceptualized as a four-phase system: two mobile colloidal phases, an aqueous phase, and a stationary solid phase. An equilibrium approach is used to describe the interactions of Contaminants with DOM, bacteria, and solid matrix. The model is composed of bacterial transport equation and Contaminant transport equation. Numerical simulations are performed to examine the Contaminant transport behavior in the presence of DOM and bacteria. The simulation results illustrate that Contaminant transport is enhanced markedly in the presence of DOM and bacteria, and the impact of DOM on Contaminant mobility is greater than that of bacteria under examined conditions. Sensitivity analysis demonstrates that the model is sensitive to changes of three lumped parameters: K1 + (total affinity of stationary solid phase to Contaminants), K2 + (total affinity of DOM to Contaminants), and K3 + (total affinity of bacteria to Contaminants). In a situation where Contaminants exist simultaneously with DOM and bacteria, Contaminant transport is mainly affected by a ratio of K1 + /K2 + /K3 + , which can vary with changes of equilibrium distribution coefficient of Contaminants and/or colloidal concentrations. In riverbank filtration, the influence of DOM and bacteria on the transport behavior of Contaminants should be accounted to accurately predict the Contaminant mobility. D 2003 Elsevier Science B.V. All rights reserved.
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Contaminant transport in riverbank filtration in the presence of dissolved organic matter and bacteria a kinetic approach
Journal of Hydrology, 2002Co-Authors: Song-bae Kim, Yavuz M CorapciogluAbstract:In riverbank filtration, the removal of organic Contaminants is an important task for the production of good quality drinking water. The transport of an organic Contaminant in riverbank filtration can be retarded by sorption on to the solid matrix and facilitated by the presence of mobile colloids. In the presence of dissolved organic matter (DOM) and bacteria, the subsurface environment can be modeled as a four-phase porous medium: two mobile colloidal phases, an aqueous phase, and a solid matrix. In this study, a kinetic model is developed to simulate the Contaminant transport in riverbank filtration in the presence of DOM and bacteria. The bacterial deposition and the Contaminant sorption on bacteria and DOM are expressed with kinetic expressions. The model equations are solved numerically with a fully implicit finite difference method. Simulation results show that the Contaminant mobility increases greatly in riverbank filtration due to the presence of DOM. The mobility can be enhanced further when the bacteria and DOM are present together in the aquifer. In this system, the total aqueous phase Contaminant concentration, Cct+, includes the Contaminant dissolved in the aqueous phase, Cc+, the Contaminant sorbed to DOM, σcd+, and the Contaminant sorbed to mobile bacteria, Cb+σcbm+, (i.e. Cct+=Cc++σcd++Cb+σcbm+). Sensitivity analysis illustrates that the distribution of the total aqueous phase Contaminants among the dissolved phase, DOM and bacteria is changed significantly with various Damkohler numbers related to the Contaminant sorption on mobile colloids.
Song-bae Kim - One of the best experts on this subject based on the ideXlab platform.
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effect of dissolved organic matter and bacteria on Contaminant transport in riverbank filtration
Journal of Contaminant Hydrology, 2003Co-Authors: Song-bae Kim, Yavuz M Corapcioglu, Dong Ju KimAbstract:A mathematical model for the transport of hydrophobic organic Contaminants in an aquifer under simplistic riverbank filtration conditions is developed. The model considers a situation where Contaminants are present together with dissolved organic matter (DOM) and bacteria. The aquifer is conceptualized as a four-phase system: two mobile colloidal phases, an aqueous phase, and a stationary solid phase. An equilibrium approach is used to describe the interactions of Contaminants with DOM, bacteria, and solid matrix. The model is composed of bacterial transport equation and Contaminant transport equation. Numerical simulations are performed to examine the Contaminant transport behavior in the presence of DOM and bacteria. The simulation results illustrate that Contaminant transport is enhanced markedly in the presence of DOM and bacteria, and the impact of DOM on Contaminant mobility is greater than that of bacteria under examined conditions. Sensitivity analysis demonstrates that the model is sensitive to changes of three lumped parameters: K1 + (total affinity of stationary solid phase to Contaminants), K2 + (total affinity of DOM to Contaminants), and K3 + (total affinity of bacteria to Contaminants). In a situation where Contaminants exist simultaneously with DOM and bacteria, Contaminant transport is mainly affected by a ratio of K1 + /K2 + /K3 + , which can vary with changes of equilibrium distribution coefficient of Contaminants and/or colloidal concentrations. In riverbank filtration, the influence of DOM and bacteria on the transport behavior of Contaminants should be accounted to accurately predict the Contaminant mobility. D 2003 Elsevier Science B.V. All rights reserved.
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Contaminant transport in riverbank filtration in the presence of dissolved organic matter and bacteria a kinetic approach
Journal of Hydrology, 2002Co-Authors: Song-bae Kim, Yavuz M CorapciogluAbstract:In riverbank filtration, the removal of organic Contaminants is an important task for the production of good quality drinking water. The transport of an organic Contaminant in riverbank filtration can be retarded by sorption on to the solid matrix and facilitated by the presence of mobile colloids. In the presence of dissolved organic matter (DOM) and bacteria, the subsurface environment can be modeled as a four-phase porous medium: two mobile colloidal phases, an aqueous phase, and a solid matrix. In this study, a kinetic model is developed to simulate the Contaminant transport in riverbank filtration in the presence of DOM and bacteria. The bacterial deposition and the Contaminant sorption on bacteria and DOM are expressed with kinetic expressions. The model equations are solved numerically with a fully implicit finite difference method. Simulation results show that the Contaminant mobility increases greatly in riverbank filtration due to the presence of DOM. The mobility can be enhanced further when the bacteria and DOM are present together in the aquifer. In this system, the total aqueous phase Contaminant concentration, Cct+, includes the Contaminant dissolved in the aqueous phase, Cc+, the Contaminant sorbed to DOM, σcd+, and the Contaminant sorbed to mobile bacteria, Cb+σcbm+, (i.e. Cct+=Cc++σcd++Cb+σcbm+). Sensitivity analysis illustrates that the distribution of the total aqueous phase Contaminants among the dissolved phase, DOM and bacteria is changed significantly with various Damkohler numbers related to the Contaminant sorption on mobile colloids.
William H. Clements - One of the best experts on this subject based on the ideXlab platform.
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community responses to Contaminants using basic ecological principles to predict ecotoxicological effects
Environmental Toxicology and Chemistry, 2009Co-Authors: William H. Clements, Jason R RohrAbstract:Community ecotoxicology is defined as the study of the effects of Contaminants on patterns of species abundance, diversity, community composition, and species interactions. Recent discoveries that species diversity is positively associated with ecosystem stability, recovery, and services have made a community-level perspective on ecotoxicology more important than ever. Community ecotoxicology must explicitly consider both present and impending global change and shift from a purely descriptive to a more predictive science. Greater consideration of the ecological factors and threshold responses that determine community resistance and resilience should improve our ability to predict how and when communities will respond to, and recover from, xenobiotics. A better understanding of pollution-induced community tolerance, and of the costs of this tolerance, should facilitate identifying Contaminant- impacted communities, thus forecasting the ecological consequences of Contaminant exposure and determining the restoration effectiveness. Given the vast complexity of community ecotoxicology, simplifying assumptions, such as the possibility that the approximately 100,000 registered chemicals could be reduced to a more manageable number of Contaminant classes with similar modes of action, must be identified and validated. In addition to providing a framework for predicting Contaminant fate and effects, food-web ecology can help to identify communities that are sensitive to Contaminants, Contaminants that are particularly insidious to communities, and species that are crucial for transmitting adverse effects across trophic levels. Integration of basic ecological principles into the design and implementation of ecotoxicological research is essential for predicting Contaminant effects within the context of rapidly changing, global environmental conditions. Keywords—Community ecotoxicology Contaminant transport Global change Indirect effects Resistance/resilience
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community responses to Contaminants using basic ecological principles to predict ecotoxicological effects
Environmental Toxicology and Chemistry, 2009Co-Authors: William H. Clements, Jason R RohrAbstract:Community ecotoxicology is defined as the study of the effects of Contaminants on patterns of species abundance, diversity, community composition, and species interactions. Recent discoveries that species diversity is positively associated with ecosystem stability, recovery, and services have made a community-level perspective on ecotoxicology more important than ever. Community ecotoxicology must explicitly consider both present and impending global change and shift from a purely descriptive to a more predictive science. Greater consideration of the ecological factors and threshold responses that determine community resistance and resilience should improve our ability to predict how and when communities will respond to, and recover from, xenobiotics. A better understanding of pollution-induced community tolerance, and of the costs of this tolerance, should facilitate identifying Contaminant-impacted communities, thus forecasting the ecological consequences of Contaminant exposure and determining the restoration effectiveness. Given the vast complexity of community ecotoxicology, simplifying assumptions, such as the possibility that the approximately 100,000 registered chemicals could be reduced to a more manageable number of Contaminant classes with similar modes of action, must be identified and validated. In addition to providing a framework for predicting Contaminant fate and effects, food-web ecology can help to identify communities that are sensitive to Contaminants, Contaminants that are particularly insidious to communities, and species that are crucial for transmitting adverse effects across trophic levels. Integration of basic ecological principles into the design and implementation of ecotoxicological research is essential for predicting Contaminant effects within the context of rapidly changing, global environmental conditions.
Sage R Hiibel - One of the best experts on this subject based on the ideXlab platform.
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evaluation of semi volatile Contaminant transport in a novel gas tight direct contact membrane distillation system
Desalination, 2018Co-Authors: Kevin A Salls, Danbi Won, Edward P Kolodziej, Amy E Childress, Sage R HiibelAbstract:Abstract A first-of-its-kind, gas-tight MD system was designed to provide insight into the dynamic transport of semi-volatile Contaminants over time by closing the mass balance for each Contaminant. Testing with non-volatile ions was used to confirm the integrity of the test system and sampling procedures. Non-volatile Contaminants had consistently high rejection rates (≥ 99%) for all analytes tested. For the most hydrophobic semi-volatile Contaminants, sorption to the membrane and polymeric components within the system played a significant role in their fate. Less hydrophobic semi-volatile Contaminants reached a pseudo-equilibrium governed largely by Contaminant volatility, as predicted by Henry's Law. Rejection of semi-volatile nitrosamines varied from − 96 to 88%, demonstrating significant variation in behavior even within the same Contaminant class. Results suggest that transport of semi-volatile Contaminants in MD was consistent with a pseudo-equilibrium partitioning process and was highly correlated with Contaminant volatility (R2 = 0.934 for the combined data set). These results have implications for treatment of complex source waters where an understanding of the transport of volatile components is needed even if treatment objectives are focused on nonvolatile components.
