Search Results - "Widdowson, Mark A"

Evaluating Flow Distribution in a Multiaquifer Recharge Well Using an In Situ Flowmeter by Martinez, Meredith B., Widdowson, Mark A.

“…Quantifying the flow rate distribution in a multiple‐screen recharge well is relevant to understanding groundwater flow and solute transport behavior in…”
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Effect of Surface Water Stage Fluctuation on Mixing‐Dependent Hyporheic Denitrification in Riverbed Dunes by Hester, Erich T., Eastes, Lauren A., Widdowson, Mark A.

“…The hyporheic zone, where surface water (SW) and groundwater (GW) interact in shallow sediments beneath rivers, is uniquely reactive and attenuates pollutants…”
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Effects of boundary hydraulics, dissolved oxygen, and dissolved organic carbon on growth and death dynamics of aerobic microbes in riverbed dune-induced hyporheic zones by Monterroso, Hector, Widdowson, Mark A., Lotts, W. Seth, Strom, Kyle B., Hester, Erich T.

“…Surface and groundwater interact in the hyporheic zone beneath and adjacent to rivers in the presence of a diverse microbial community. Heterotrophic bacteria…”
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Numerical Modeling and Data‐Worth Analysis for Characterizing the Architecture and Dissolution Rates of a Multicomponent DNAPL Source by Prieto‐Estrada, Andres E., Widdowson, Mark A., Stewart, Lloyd D.

“…A numerical solute transport model was calibrated to a high‐resolution monitoring data set to characterize a multicomponent source of nonaqueous phase liquids…”
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Abiotic Mixing‐Dependent Reaction in a Laboratory Simulated Hyporheic Zone by Santizo, Katherine Y., Widdowson, Mark A., Hester, Erich T.

“…Groundwater (GW) contaminants upwelling toward surface water (SW) can attenuate in the hyporheic zone, with dissolved oxygen (DO) frequently controlling the…”
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Numerical modeling of an abiotic hyporheic mixing-dependent reaction: Chemical evolution of mixing and reactant production zones by Santizo, Katherine Y., Widdowson, Mark A., Hester, Erich T.

“…Mixing-dependent reactions occur where groundwater and surface water mix in shallow sediments (hyporheic zone) and can attenuate contaminants along upwelling…”
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Upscaled modeling of complex DNAPL dissolution by Stewart, Lloyd D., Chambon, Julie C., Widdowson, Mark A., Kavanaugh, Michael C.

“…A straightforward, upscaled DNAPL mass dissolution model is developed using relatively simple input consisting of characteristic dimensions and saturations of…”
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Hyporheic transverse mixing zones and dispersivity: Laboratory and numerical experiments of hydraulic controls by Hester, Erich T., Santizo, Katherine Y., Nida, Abenezer A., Widdowson, Mark A.

“…Mixing of surface water and groundwater in shallow sediments is important to biogeochemical cycling and contaminant migration, and is often used to define the…”
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Demonstration of Managed Aquifer Recharge in a Coastal Plain Aquifer: Lessons Learned by Martinez, Meredith B., Widdowson, Mark A., Bott, Charles, Holloway, Dan, Heisig‐Mitchell, Jamie, Wilson, Christopher

“…The sustainable water initiative for tomorrow (SWIFT) is a 378,000 m3/day (100 MGD) managed aquifer recharge (MAR) program designed by the Hampton Roads…”
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Controls on mixing-dependent denitrification in hyporheic zones induced by riverbed dunes: A steady state modeling study by Hester, Erich T., Young, Katie I., Widdowson, Mark A.

“…The hyporheic zone is known to attenuate contaminants originating from surface water, yet the ability of the hyporheic zone to attenuate contaminants in…”
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Direct Volatilization of Naphthalene to the Atmosphere at a Phytoremediation Site by Marr, Linsey C, Booth, Elizabeth C, Andersen, Rikke G, Widdowson, Mark A, Novak, John T

“…Phytoremediation systems are known to reduce groundwater contamination by at least three major mechanisms:  plant uptake, phytovolatilization, and enhanced…”
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Modeling of Complex Reductive Biodegradation Kinetics of Recalcitrant Organic Contaminants by Gupta, Ankit, Widdowson, Mark A

“…AbstractA kinetic model based on the Michaelis-Menten kinetic equations for simulating the complex reductive biodegradation kinetics of groundwater…”
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Effect of biostimulants on 2,4,6-trinitrotoluene (TNT) degradation and bacterial community composition in contaminated aquifer sediment enrichments by Fahrenfeld, Nicole, Zoeckler, Jeffrey, Widdowson, Mark A., Pruden, Amy

“…2,4,6-Trinitrotoluene (TNT) is a toxic and persistent explosive compound occurring as a contaminant at numerous sites worldwide. Knowledge of the microbial…”
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Modeling of Complex, Multi‐Component NAPL Remediation for Decision Support by Stewart, Lloyd D., Nyman, Jennifer, Prieto‐Estrada, Andres E., Chambon, Julie C., Widdowson, Mark A., Kavanaugh, Michael C.

“…In situ remediation of nonaqueous phase liquid (NAPL)‐impacted sites is difficult and costly. Even with enhancements (e.g., chemical and thermal) and partial…”
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Influence of Petroleum Deposit Geometry on Local Gradient of Electron Acceptors and Microbial Catabolic Potential by Singh, Gargi, Pruden, Amy, Widdowson, Mark A

“…A field survey was conducted following the Deepwater Horizon blowout and it was noted that resulting coastal petroleum deposits possessed distinct geometries,…”
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Multicomponent NAPL Source Dissolution: Evaluation of Mass-Transfer Coefficients by Mobile, Michael A, Widdowson, Mark A, Gallagher, Daniel L

“…Mass transfer rate coefficients were quantified by employing an inverse modeling technique to high-resolution aqueous phase concentration data observed…”
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Modeling Long-Term Trends of Chlorinated Ethene Contamination at a Public Supply Well by Chapelle, Francis H., Kauffman, Leon J., Widdowson, Mark A.

“…A mass‐balance solute‐transport modeling approach was used to investigate the effects of dense nonaqueous phase liquid (DNAPL) volume, composition, and…”
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Modeling the Effects of Naturally Occurring Organic Carbon on Chlorinated Ethene Transport to a Public Supply Well by Chapelle, Francis H, Kauffman, Leon J, Widdowson, Mark A

“…The vulnerability of public supply wells to chlorinated ethene (CE) contamination in part depends on the availability of naturally occurring organic carbon to…”
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Evaluation of in‐service residential nutating disc water meter performance by Mantilla‐Peña, Carlos F., Widdowson, Mark A., Boardman, Gregory D.

“…This article reports the experimental evaluation of registry error of in‐service residential water meters and the effects of service time (ST) and volumetric…”
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Volatilization and Biodegradation of Naphthalene in the Vadose Zone Impacted by Phytoremediation by Andersen, Rikke G, Booth, Elizabeth C, Marr, Linsey C, Widdowson, Mark A, Novak, John T

“…The combined remediation mechanisms of volatilization and biodegradation in the vadose zone were investigated for naphthalene remediation at a…”
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