Stable isotope ratios as a tool to assess biodegradation of methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA)

摘要

The aim of this study was to evaluate if compound-specific isotope analysis can be used to assess biodegradation of MTBE. The effect of aerobic biodegradation on carbon isotope ratios of MTBE was evaluated using microcosms with MTBE as the only substrate and cometabolic microcosms with 3-methylpentane as the primary substrate. In both types of microcosm, the δ~(13)C of MTBE steadily increased as degradation proceeded while no change in δ~(13)C occurred in control experiments. After >95% degradation, a shift in δ~(13)C of 5.1 to 6.9% was observed. The δ~(13)C of TBA, which accumulated transiently in the cometabolic microcosm, increased by 4.3per thousand confirming that TBA was also degraded. This study suggests that carbon isotope analysis is a potential tool for tracing in situ biodegradation of MTBE and TBA, and thus to aid better understanding of the fate of these contaminants in the environment.