| Title: | Bioremediation of chlorinated ethenes in fractured bedrock and associated changes in dechlorinating and nondechlorinating microbial populations |
| Author(s): | Perez-de-Mora A; Zila A; McMaster ML; Edwards EA; |
| Address: | "Department of Chemical Engineering and Applied Chemistry, University of Toronto , 200 College Street, Toronto, Ontario M5S 3E5N, Canada" |
| ISSN/ISBN: | 1520-5851 (Electronic) 0013-936X (Linking) |
| Abstract: | "The use of enhanced in situ anaerobic bioremediation (EISB) and bioaugmentation in fractured bedrock is limited compared to its use in granular media. We evaluated EISB for the treatment of trichloroethene (TCE)-impacted groundwater in fractured carbonate rock at a site in Southern Ontario, Canada, with cool average groundwater temperature ( approximately 13 degrees C). Borehole-connectivity, contaminant concentrations, and groundwater properties were investigated. Changes in dechlorinating and nondechlorinating populations (fermenters, acetogens, methanogens, and sulfate reducers) were assessed via quantitative PCR (qPCR). During biostimulation with ethanol, concentrations of TCE daughter products cis-dichloroethene (cDCE) and vinyl chloride (VC) decreased in association with an enrichment of vcrA (VC reductive dehalogenase)-carrying Dehalococcoides, whereas ethene production was only moderate. Following bioaugmentation with the mixed dechlorinating culture KB-1, greater concentrations of chloride-a product of dechlorination-was observed in most wells; in addition, ethene production increased significantly in monitoring well locations that had strong hydraulic connectivity to the groundwater recirculation system, while Dehalococcoides and vcrA concentrations did not appreciably vary. Interestingly, increases of 3-4 orders of magnitude of an ethanol-fermenting Bacteroidetes population also present in KB-1 were correlated to improved conversion to ethene, an observation which suggests there could be a causal relationship-for example, better syntrophy and/or synergy among bacterial populations" |
| Keywords: | "Bacteria/*metabolism Biodegradation, Environmental Biotransformation Chlorides/analysis Ethylenes/*isolation & purification Geologic Sediments/*chemistry Groundwater/chemistry *Halogenation Ontario Volatile Organic Compounds/metabolism;" |
| Notes: | "MedlinePerez-de-Mora, Alfredo Zila, Anna McMaster, Michaye L Edwards, Elizabeth A eng Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. 2014/04/15 Environ Sci Technol. 2014 May 20; 48(10):5770-9. doi: 10.1021/es404122y. Epub 2014 May 7" |
