חיפוש מתקדם
Hunkeler, D., Centre for Hydrogeology and Geothermics (CHYN), University of Neuchâtel, Rue Emile Argand 11, CH-2000 Neuchâtel, Switzerland
Aravena, R., Department of Earth and Environmental Sciences, University of Waterloo, Waterloo N2L 3G1, Canada
Shouakar-Stash, O., Department of Earth and Environmental Sciences, University of Waterloo, Waterloo N2L 3G1, Canada
Weisbrod, N., Department of Environmental Hydrology and Microbiology, Zuckerberg Institute for Water Research, Ben Gurion University of the Negev, Sde Boker Campus 84990, Israel
Nasser, A., Institute of Soil, Water and Environmental Sciences, Volcani Center, Agricultural Research Organization, POB 6, Bet Dagan 50250, Israel
Netzer, L., Department of Environmental Hydrology and Microbiology, Zuckerberg Institute for Water Research, Ben Gurion University of the Negev, Sde Boker Campus 84990, Israel
Ronen, D., Department of Environmental Hydrology and Microbiology, Zuckerberg Institute for Water Research, Ben Gurion University of the Negev, Sde Boker Campus 84990, Israel, Israel Water Authority, POB 20365, Tel Aviv 61203, Israel
Compound-specific isotope analysis (CSIA) can potentially be used to relate vapor phase contamination by volatile organic compounds (VOCs) to their subsurface sources. This field and modeling study investigated how isotope ratios evolve during migration of gaseous chlorinated ethenes across a 18 m thick unsaturated zone of a sandy coastal plain aquifer. At the site, high concentrations of tetrachloroethene (PCE up to 380 μg/L), trichloroethene (TCE up to 31,600 μg/L), and cis-1,2-dichloroethene (cDCE up to 680 μg/L) were detected in groundwater. Chlorinated ethene concentrations were highest at the water table and steadily decreased upward toward the land surface and downward below the water table. Although isotopologues have different diffusion coefficients, constant carbon and chlorine isotope ratios were observed throughout the unsaturated zone, which corresponded to the isotope ratios measured at the water table. In the saturated zone, TCE became increasingly depleted along a concentration gradient, possibly due to isotope fractionation associated with aqueous phase diffusion. These results indicate that carbon and chlorine isotopes can be used to link vapor phase contamination to their source even if extensive migration of the vapors occurs. However, the numerical model revealed that constant isotope ratios are only expected for systems close to steady state. © 2011 American Chemical Society.
פותח על ידי קלירמאש פתרונות בע"מ -
הספר "אוצר וולקני"
אודות
תנאי שימוש
Carbon and chlorine isotope ratios of chlorinated ethenes migrating through a thick unsaturated zone of a sandy aquifer
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Hunkeler, D., Centre for Hydrogeology and Geothermics (CHYN), University of Neuchâtel, Rue Emile Argand 11, CH-2000 Neuchâtel, Switzerland
Aravena, R., Department of Earth and Environmental Sciences, University of Waterloo, Waterloo N2L 3G1, Canada
Shouakar-Stash, O., Department of Earth and Environmental Sciences, University of Waterloo, Waterloo N2L 3G1, Canada
Weisbrod, N., Department of Environmental Hydrology and Microbiology, Zuckerberg Institute for Water Research, Ben Gurion University of the Negev, Sde Boker Campus 84990, Israel
Nasser, A., Institute of Soil, Water and Environmental Sciences, Volcani Center, Agricultural Research Organization, POB 6, Bet Dagan 50250, Israel
Netzer, L., Department of Environmental Hydrology and Microbiology, Zuckerberg Institute for Water Research, Ben Gurion University of the Negev, Sde Boker Campus 84990, Israel
Ronen, D., Department of Environmental Hydrology and Microbiology, Zuckerberg Institute for Water Research, Ben Gurion University of the Negev, Sde Boker Campus 84990, Israel, Israel Water Authority, POB 20365, Tel Aviv 61203, Israel
Carbon and chlorine isotope ratios of chlorinated ethenes migrating through a thick unsaturated zone of a sandy aquifer
Compound-specific isotope analysis (CSIA) can potentially be used to relate vapor phase contamination by volatile organic compounds (VOCs) to their subsurface sources. This field and modeling study investigated how isotope ratios evolve during migration of gaseous chlorinated ethenes across a 18 m thick unsaturated zone of a sandy coastal plain aquifer. At the site, high concentrations of tetrachloroethene (PCE up to 380 μg/L), trichloroethene (TCE up to 31,600 μg/L), and cis-1,2-dichloroethene (cDCE up to 680 μg/L) were detected in groundwater. Chlorinated ethene concentrations were highest at the water table and steadily decreased upward toward the land surface and downward below the water table. Although isotopologues have different diffusion coefficients, constant carbon and chlorine isotope ratios were observed throughout the unsaturated zone, which corresponded to the isotope ratios measured at the water table. In the saturated zone, TCE became increasingly depleted along a concentration gradient, possibly due to isotope fractionation associated with aqueous phase diffusion. These results indicate that carbon and chlorine isotopes can be used to link vapor phase contamination to their source even if extensive migration of the vapors occurs. However, the numerical model revealed that constant isotope ratios are only expected for systems close to steady state. © 2011 American Chemical Society.
Scientific Publication
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