Carbon and Chlorine Isotope Fractionation During Microbial Degradation of Tetra- and Trichloroethene
| Autor: | Rich D Pancost, Christoph Aeppli, Örjan Gustafsson, Jiřina Macháčková, Richard P. Evershed, Paraskevi N. Polymenakou, Timothy D J Knowles, Henry Holmstrand, Manolis Mandalakis, Charline Wiegert |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
chemistry.chemical_element
010501 environmental sciences 01 natural sciences Vinyl chloride chemistry.chemical_compound Isotopes polycyclic compounds Chlorine Reductive dechlorination Environmental Chemistry Microbial biodegradation 0105 earth and related environmental sciences Isotope analysis Air Pollutants Carbon Isotopes Stable isotope ratio 010401 analytical chemistry Isotopes of chlorine General Chemistry Trichloroethylene 0104 chemical sciences Biodegradation Environmental chemistry 13. Climate action Environmental chemistry Carbon Environmental Monitoring |
| Zdroj: | Environmental Science and Technology |
| ISSN: | 1520-5851 0013-936X |
| DOI: | 10.1021/es305236y |
| Popis: | Two-dimensional compound-specific isotope analysis (2D-CSIA), combining stable carbon and chlorine isotopes, holds potential for monitoring of natural attenuation of chlorinated ethenes (CEs) in contaminated soil and groundwater. However, interpretation of 2D-CSIA data sets is challenged by a shortage of experimental Cl isotope enrichment factors. Here, isotope enrichments factors for C and Cl (i.e., εC and εCl) were determined for biodegradation of tetrachloroethene (PCE) and trichloroethene (TCE) using microbial enrichment cultures from a heavily CE-contaminated aquifer. The obtained values were εC = -5.6 ± 0.7‰ (95% CI) and εCl = -2.0 ± 0.5‰ for PCE degradation and εC = -8.8 ± 0.2‰ and εCl = -3.5 ± 0.5‰ for TCE degradation. Combining the values for both εC and εCl yielded mechanism-diagnostic εCl/εC ratios of 0.35 ± 0.11 and 0.37 ± 0.11 for the degradation of PCE and TCE, respectively. Application of the obtained εC and εCl values to a previously investigated field site gave similar estimates for the fraction of degraded contaminant as in the previous study, but with a reduced uncertainty in assessment of the natural attenuation. Furthermore, 16S rRNA gene clone library analyses were performed on three samples from the PCE degradation experiments. A species closely related to Desulfitobacterium aromaticivorans UKTL dominated the reductive dechlorination process. This study contributes to the development of 2D-CSIA as a tool for evaluating remediation strategies of CEs at contaminated sites. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|