Evaluation of intrinsic bioremediation of BTEX and chlorinated hydrocarbons at cold temperatures.

摘要

The purpose of do investigation is to evaluate the viability of intrinsic bioremediation of BTEX and chlorinated solvents at the former landfill site in CFB Cold Lake, Alberta. Investigations from 1988 to 1998 involved assessments of the soil stratigraphy, the determination of major contaminants that were deposited into the area, the location of the contaminant sources and the delineation of plume extent. The contaminants evaluated include chlorinated aliphatic hydrocarbons (CAHs), such as 1,1,1-trichloroethane (PCA),1,1-dichloroethane (DCA), and benzene, toluene, ethylbenzene, and xylenes (BTEX). Microcosm tests were set up to represent two sites at two different temperatures (10°C and 20°C), to determine a first order rate of biodegradation. Although no discernable trends were observed in the microcosm tests, the field results indicate that the site conditions are conducive for intrinsic bioremediation. The CAHs and BTEX concentrations are decreasing downgradient from the source, daughter products such as DCA are being formed, and the microbial degradation products such as iron (II) and methane increase in concentration close the source of contamination and downgradient of the source.