title: In-situ biodegradation of tetrachloroethene and trichloroethene in contaminated aquifers monitored by stable isotope fractionation.
abstract: Stable carbon isotope analysis of tetrachloroethene (PCE) and trichloroethene (TCE) was applied to evaluatenatural attenuation processes in the upper Quaternary and lower Tertiary aquifer in the area of a former dry-cleaning plant located in Leipzig, Germany. Groundwater samples were taken during one monitoring campaign in 2001. The 13C enrichment in contaminants along the water flow path suggested that both, PCE and TCE were degraded in the Quaternary aquifer. The enrichment of 13C in the residual PCE fraction and an isotope fractionation factor from laboratory experiments were used to calculate the extent of biodegradation in the Quatemary aquifer. These calculations indicated that a major portion of PCE was biodegraded in the course of the plume. In the Tertiary aquifer the carbon isotope ratios of PCE and TCE indicated that the decreasing concentrations of these contaminants were probably not caused by microbial processes.
authors.affiliation: UFZ Centre for Environmental Research Leipzig-Halle, 04318 Leipzig, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Vieth
authors.forename: J
authors.initials: J
authors.lastname: Müller
authors.forename: G
authors.initials: G
authors.lastname: Strauch
authors.forename: M
authors.initials: M
authors.lastname: Kästner
authors.forename: M
authors.initials: M
authors.lastname: Gehre
authors.forename: R U
authors.initials: RU
authors.lastname: Meckenstock
authors.forename: H H
authors.initials: HH
authors.lastname: Richnow
mesh_terms: D001673:Biodegradation, Environmental; D002247:Carbon Isotopes / Q000032:analysis; D004784:Environmental Monitoring / Q000379:methods; D004785:Environmental Pollutants / Q000378:metabolism*; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism; D012997:Solvents / Q000378:metabolism*; D013750:Tetrachloroethylene / Q000378:metabolism*; D014241:Trichloroethylene / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism
chemical_list: D002247:Carbon Isotopes; D004785:Environmental Pollutants; D012989:Soil Pollutants; D012997:Solvents; D014874:Water Pollutants, Chemical; D014241:Trichloroethylene; D013750:Tetrachloroethylene