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Characterizing The Microbial Community In A TCE DNAPL Site: SABRE Column And Field Studies
Citation:
Dworatzek, S., R. F. HERRMANN, T. DAHLING, C. M. ACHESON, D. W. Major, M. Harkness, M. D. Lee, AND E. E. Mack. Characterizing The Microbial Community In A TCE DNAPL Site: SABRE Column And Field Studies. Presented at Battelle In Situ and On-Site Bioremediation 10th International Symposium, Baltimore, MD, May 05 - 09, 2009.
Impact/Purpose:
To summarize the column study microbial characterization results and compare them to the results obtained from the field scale pilot test.
Description:
The SABRE (Source Area BioREmediation) project is evaluating accelerated anaerobic bioremediation of chlorinated solvents in areas of high concentration, such as DNAPL source areas. In support of a field scale pilot test, column studies were conducted to design the system and obtain modeling information. Samples for microbial characterization have been collected throughout this project including microcosm studies, column studies, and from the field studies during the baseline, biostimulation with SRS, and post-bioaugmentation periods. Results from the microcosm study and column study have been previously presented. While treatment performance is assessed based on the chemical concentrations of TCE and dechlorination products, the microbial community may provide useful information on treatment operation and may assist in troubleshooting problems. For the SABRE project, the microbial community was characterized using three techniques: quantitative polymerase chain reaction (qPCR) for enumeration of Dehalococcoides organisms (Dhc) and for the vinyl chloride reductase (vcr) gene; denaturing gradient gel electrophoresis (DGGE); and phospholipid fatty acid analysis (PFLA). Dhc were tracked as these microbes are capable of complete reductive dechlorination of TCE to ethene. The vcr test provides quantitative information regarding the relative abundance of the gene that encodes for the enzyme that dechlorinates vinyl chloride to ethene. This test determines if the detected Dehalococcoides will degrade VC to ethene efficiently and may be used to evaluate the activity of indigenous and bioaugmented Dhc. DGGE was used to assess and monitor changes in the composition of the microbial communities based upon DNA samples taken from various laboratory studies and over time in the field study. PLFA was used to describe the size and structure of the microbial community based on the phospholipids present in cell membranes. In combination, these three molecular techniques provide a robust understanding of the microbial community. This presentation will summarize the column study microbial characterization results and compare them to the results obtained from the field scale pilot test.
URLs/Downloads:
Characterizing The Microbial Community In A TCE DNAPL Site: SABRE Column And Field Studies (PDF, NA pp, 9 KB, about PDF)Conference Program
