Search Result
LONG-TERM PERFORMANCE ASSESSMENT AT A HIGHLY CHARACTERIZED AND INSTRUMENTED DNAPL SOURCE AREA FOLLOWING BIOAUGMENTATION
Schaefer, C., G. Lavorgna, M. Annable, and A. Haluska.
ESTCP Project ER-201428, 167 pp, 2018
Filed Under: Demonstrations
Filed Under: Demonstrations
In a study of long-term behavior in chlorinated ethene DNAPL source areas following in situ bioaugmentation in heterogeneous media, monitoring was performed up to 3.7 years following active TCE bioremediation using a high-density monitoring network. Soil sampling, passive flux meters, and push-pull tracer testing was performed. Results showed that biogeochemical conditions remained favorable for reductive dechlorination of chlorinated ethenes despite the absence of lactate, lactate fermentation transformation products, or hydrogen. While ethene levels suggested relatively low dechlorination of the parent TCE and daughter products, CSIA showed that the extent of complete dechlorination was much greater than indicated by ethene generation. Results of push-pull tracer testing confirmed that DNAPL remained in a portion of the source area, consistent with soil and groundwater data. Overall study results suggest biological processes have the potential to persist to treat TCE years after cessation of active bioremediation, thereby serving as an important component of remedial design and long-term attenuation. Reliance on ethene generation alone as an indicator of complete dechlorination significantly underestimated the extent of complete dechlorination, as CSIA analysis provided a more reliable estimate, thus highlighting the importance of utilizing isotopic data to determine dechlorination rates in complex systems. Results also emphasized the importance of high-resolution characterization and monitoring in facilitating improved design and performance monitoring. https://www.serdp-estcp.org/content/download/47280/451089/file/ER-201428%20Final%20Report.pdf
ESTCP Project ER-201428, 167 pp, 2018
Filed Under: Demonstrations
Filed Under: Demonstrations
In a study of long-term behavior in chlorinated ethene DNAPL source areas following in situ bioaugmentation in heterogeneous media, monitoring was performed up to 3.7 years following active TCE bioremediation using a high-density monitoring network. Soil sampling, passive flux meters, and push-pull tracer testing was performed. Results showed that biogeochemical conditions remained favorable for reductive dechlorination of chlorinated ethenes despite the absence of lactate, lactate fermentation transformation products, or hydrogen. While ethene levels suggested relatively low dechlorination of the parent TCE and daughter products, CSIA showed that the extent of complete dechlorination was much greater than indicated by ethene generation. Results of push-pull tracer testing confirmed that DNAPL remained in a portion of the source area, consistent with soil and groundwater data. Overall study results suggest biological processes have the potential to persist to treat TCE years after cessation of active bioremediation, thereby serving as an important component of remedial design and long-term attenuation. Reliance on ethene generation alone as an indicator of complete dechlorination significantly underestimated the extent of complete dechlorination, as CSIA analysis provided a more reliable estimate, thus highlighting the importance of utilizing isotopic data to determine dechlorination rates in complex systems. Results also emphasized the importance of high-resolution characterization and monitoring in facilitating improved design and performance monitoring. https://www.serdp-estcp.org/content/download/47280/451089/file/ER-201428
The Technology Innovation News Survey welcomes your comments and
suggestions, as well as information about errors for correction. Please
contact Michael Adam of the U.S. EPA Office of Superfund Remediation
and Technology Innovation at adam.michael@epa.gov or (703) 603-9915
with any comments, suggestions, or corrections.
Mention of non-EPA documents, presentations, or papers does not constitute a U.S. EPA endorsement of their contents, only an acknowledgment that they exist and may be relevant to the Technology Innovation News Survey audience.