Effect of Ethanol on the Natural Fermentation of Benzene in Groundwater (Abstract)

摘要

Ethanol is commonly used as a fuel oxygenate in California and in the mid continent area around the Great Lakes. The presence of ethanol in a gasoline spill has raised con- cerns about the effects of the additive on the natural biodegradation of fuel hydrocarbons, including benzene. Ethanol in water provides microorganisms with an easily metabolized food source. A spill of gasoline containing ethanol would result in the partitioning of ethanol into the ground water. Electron acceptors would then be consumed in the degra- dation of ethanol and be unavailable for metabolism of benzene and fuel hydrocarbons. The process of natural anaerobic fermentation of benzene and other BTEX compounds could be inhibited by ethanol. Other studies have been conducted on the effects of etha- nol on the supply of electron acceptors in fresh spills. At many older gasoline spill sites, the soluble electron acceptors have been consumed and are not available for metabolism of benzene. Benzene in these older spills is metabolized through a fermentation reaction. This work is unique in that it addresses the effects of ethanol on benzene fermentation in aquifer sediments contaminated with gasoline.