Liquid-Phase Bioreactor for Degradation of Trichloroethylene and Benzene

摘要

The major objective was to demonstrate the efficacy of a dual-stage bioreactorsystem for the treatment of groundwater contaminated with fuels and solvents. Under this SBIR Phase II, the number of chemicals to be treated during the field demonstration was expanded to include TCE, BTEX, and dichlorobenzenes (DCBs). A pilot-scale dual-stage bioreactor system was operated at Robins AFB GA to establish proof-of-concept and to develop operational and economic information for full-scale implementation. The system included a fluidized-bed reactor (FBR), an air stripper, and a TCE gas-phase bioreactor (GPR). Due to the enhanced performance of the FBR towards TCE, the demonstration essentially became a test of two independent pilot systems, one for treatment of contaminated water in the FBR and the second for treatment of contaminated air in the GPR. Operation of the system demonstrated effective treatment of not only BTEX and DCB, but also TCE. Over 210,000 gallons of contaminated groundwater were effectively treated during the demonstration. All hazardous chemicals were treated to concentrations near or below drinking water standards. An economic evaluation of the FBR to UV-peroxidation, air stripping with carbon adsorption, wet carbon adsorption and air stripping followed by PURUS adsorption suggests a significant cost savings over the life of a typical project.