In-Situ Bioremediation of Methyl Tertiary Butyl Ether (MTBE) - Advanced Fuel Hydrocarbon Remediation National Test Location

摘要

Equilon's Westhollow Technology Center teamed with Arizona State University to evaluate an in-situ process for bioremediation of methyl tertiary butyl ether (MTBE). MTBE is a gasoline additive that was introduced in fuels to reduce emission of a number of air pollutants including carbon monoxide (CO). Navy sites where MTBE contamination is present. Since MTBE is required in regions of the country that exceed ambient standards for CO, it often is found in urban areas. The U.S. EPA issued a health advisory for MTBE in 1997 indicating that the drinking water level should be less than 40 micro g/L based in odor and taste thresholds. Recent laboratory experiments and limited field studies have demonstrated that MTBE can be aerobically degraded by a bacterial culture, BC-4, developed by the Shell Development Company. BC-4 grows naturally in activated sludge at industrial wastewater treatment plants. The BC-4 culture is a mixture of ordinary soil bacteria such as coryneforms, pseudomonads, and achromobacter species that have been acclimated to MTBE for more than a year. Bioreactor studies with BC-4 in the presence of oxygen have shown 99% removal of MTBE from groundwater, based on a 25-hour retention time. The end products of the degradation are carbon dioxide and water. The field trial, which is the first of its kind for treatment of MTBE, is focusing on the use of BC-4 as an in-situ bio-barrier to downgradient MTBE migration.