MICROBIAL-DEGRADATION OF 1,2-DIBROMOETHANE IN SHALLOW AQUIFER MATERIALS

The objective of this study was to determine the importance of microbial degradation to natural decontamination of 1,2-dibromoethane (ethylene dibromide, EDB) in aquifer materials. Shallow aquifer materials were obtained from two sites in Connecticut that are contaminated with EDB. Ethylene dibromide was degraded aerobically in all samples except autoclaved controls; products of left bracket **1**4C right bracket -EDB degradation included varying amounts of **1**4CO//2, solid-bound **1**4C (microbial biomass), and a nonvolatile water soluble fraction. At one of the sites, rates were faster in samples obtained from within the contaminant plume, suggesting adaptation of the microbial community to the presence of the chemical. Degradation was slowed at low-oxygen compared to air-saturated conditions. Additional study results are discussed.