ASSESSMENT OF GREAT LAKES AREAS OF CONCERN SEDIMENTS FOR ACTIVATED CARBON TREATMENT
Investigator: U. Ghosh
Duration: January 2005 - July 2006.
Funding agency: EPA Great Lakes National Program Office

Background. The Great Lakes Areas of Concern are some of the most impacted sediment sites in the country. Remediation of these large sediment sites is complicated by the enormous cost involved and the lack of innovative technologies. The most commonly considered alternatives for PCB-contaminated sediment management are (1) dredging and placement in confined disposal facilities (CDFs) or hazardous waste landfills and (2) capping, an option for containment in engineered subaqueous sites. However, either option is expensive and requires large-scale material handling and long-term management. In addition, dredging operations can cause temporary high levels of contaminants in the water column and surficial sediments due to resuspension of buried sediments and release of pore water. Natural attenuation of PCBs through anaerobic dechlorination has been demonstrated but has not been widely adopted as a remedial alternative due partly to the slow and uncertain process and continual exposure to the ecosystem during the long attenuation period. Innovative engineering solutions to the problem of persistent organic contaminants in aquatic food webs require rethinking of the existing remediation paradigm of "dredge-and-landfill."

Research Objectives. This research proposes to build on the recent finding for marine sediments of PCB bioavailability reduction through amendment with activated carbon. The research will investigate the availability of PCBs in AOC sediments to repartition into the added activated carbon.