Development of an Enhanced Bioremediation Technology for Complete Degradation of High Concentrations of Tri-, Di-, and Monochlorobenzene Using Indigenous Wetland Bacteria and the WBC-2 Dechlorinating Consortium

摘要

Background/Objectives. A remediation technology is needed to address high concentrations of tri-, di-, and monochlorobenzene and benzene in discharging groundwater and shallow wetland sediments at a Delaware Superfund site. Given the vertically upward head gradients, a reactive flow-through cap, bioaugmented with degrading microorganisms and additional materials to enhance attenuation of the contaminants, could be feasible in the wetland and creek bottom. In this study, chlorobenzene degradation efficiencies for biofilms comprised of native wetland microorganisms under anaerobic and aerobic conditions were compared to biofilms comprised of the anaerobic WBC-2 dechlorinating consortium (developed originally for degradation of chlorinated ethanes and ethenes). Biofilm performance was characterized in bioreactors using an inert polypropylene matrix and in column experiments with a granular activated carbon (GAC) matrix to evaluate a dual biofilm-sorption approach for cost-effective, in situ remediation.