M. Gordon Wolman Seminar - Kevin R. Sowers

Event Date

Tue, 02/21/2017

3:00pm - 4:00pm

Tuesday, February 21, 2017 at 3pm
Johns Hopkins Homewood Campus 
Ames Hall 234

M. Gordon Wolman Seminar presents: Microbial Bioaugmentation: A Sustainable Approach for In Situ Treatment of Polychlorinated Biphenyl-Impacted Sediments

Kevin R. Sowers
Professor and Associate Chair                                                                                                         
Department of Marine Biotechnology
University of Maryland, Baltimore County

In situ treatment by bioaugmentation has the potential to significantly reduce the environmental impact compared with dredging by reducing the health risks associated with sediment disruption, reducing overall energy use, effectively negating the requirement for extensive waste management and substantial habitat restoration.  The objective of this research is to develop and test the efficacy of a bioamended form of pelleted activated carbon (SediMite) embedded with microorganisms to concurrently sequester PCBs from the food chain and dechlorinate and degrade weathered PCBs in sediments. A pilot study was initiated in April 2015 to demonstrate and validate this environmentally sustainable technology at a PCB-impacted DoD field site. The project goal is to: 1) evaluate the efficacy of bioaugmentation for the complete degradation of highly chlorinated Aroclors in situ; and 2) evaluate the efficacy of a delivery system for deploying biocatalysts into PCB-impacted sediment through a water column.  Technical challenges for the pilot field study included production-level scale-up of the microorganisms without residual POPs, production of SediMite modified as a carrier for the bioamendments, development of an inoculation system to introduce active PCB-transforming microorganisms into SediMite pellets during deployment at the site, and maintaining viability of the anaerobes and aerobes during the deployment process. Methodology, challenges associated with deployment and final one year post-treatment results for total and aqueous concentrations of PCBs, sustainability of the bioamendment and effect on indigneous microbial populations will be discussed. On-going pilot studies at other sites will also be discussed.