Quantifying Enhanced Microbial Dehalogenation Impacting the Fate and Transport of Organohalide Mixtures in Contaminated Sediments.

摘要

The project investigated techniques and amendments to enhance microbial dehalogenation in sediments contaminated with organohalide mixtures and developed methods and tools to monitor the effectiveness of biostimulation processes. Micro- and mesocosm studies with organohalide-contaminated sediments demonstrated that these contain diverse communities of dehalogenating microorganisms. Dechlorination of historical PCB and PCDD/F contaminant mixtures can be stimulated by addition of amendments and/or bioaugmentation with dechlorinating bacteria. The enhanced dechlorination correlates with increased numbers of dehalorespirer populations and reductive dehalogenase genes. Identification of the specific microbial members associated with PCB- and PCDD/F-dechlorinating activity should allow for better strategies to enhance dehalogenation. The results provide compelling evidence to support further testing and development of biostimulation and bioaugmentation with dehalorespiring bacteria as environmentally less invasive and lower cost alternatives for in situ treatment of PCB impacted sediments.