In Situ Aerobic Cometabolic Bioremediation of TCE in Groundwater Using the PHOSter~R? Technology

摘要

The purpose of this study was to evaluate the efficacy of the PHOSter~? technology for treating groundwater contaminated with trichloroethene (TCE) at Edwards Air Force Base (AFB), California. The technology consists of injecting a gaseous mixture of air, methane, and nutrients into groundwater with the objective of stimulating the growth of methanotrophs, a naturally occurring microbial group that is capable of catalyzing the aerobic degradation of chlorinated solvents into nontoxic products. Injection operations were performed at one well for a period of three months. Six monitoring wells were utilized for groundwater and wellhead vapor monitoring and for groundwater and microbial sampling. In the five monitoring wells located within 44 ft (13 m) of the injection well, the following results were observed: dissolved oxygen concentrations increased to range between 6 and 8 milligrams per liter; the biomass of target microbial groups increased by 1 to 2 orders of magnitude; and TCE concentrations decreased by an average of 92 percent, and to below the California primary maximum contaminant level (MCL) in the well closest to the injection well. Based on the results of this study, the PHOSter~R technology was recommended for treatment of TCE contaminated groundwater at other sites at Edwards AFB.