Microbial Degradation Kinetics of Volatile Organic Hydrocarbons: Effect of BTEX Concentration and Environment: Final Report

Groundwater and soil contamination by volatile organic hydrocarbons is a widespread problem within New Jersey. The most common source of this contamination is leakage from underground storage tanks and spills at gasoline service stations, transfer terminals and tank storage yards. The soil and groundwater contaminants most commonly regulated due to this contamination are the light aromatic hydrocarbons benzene, toluene, ethylbenzene and o, m and p-xylene (BTEX) and the dominant fuel oxygenate, MTBE. Although it is known that these compounds are subject to biodegradation, there is limited understanding concerning the rate of reactions and the influence of external factors. Thus it is difficult to predict degradative capacity, and therefore to evaluate site remediation proposals for intrinsic bioremediation/natural attenuation. This report evaluates what constitutes ?reasonable? groundwater on rates for water-soluble contaminants present in gasoline. In particular, the study examines how the presence of high concentrations of contaminants affects microbial activities. The specific objective was to determine the biodegradation rates as a function of concentration for benzene, toluene and MTBE by a variety of microbial populations including those derived from New Jersey soils/sediments. ; This work was supported primarily by the New Jersey Department of Environmental Protection, Division of Science and Research (Research Contract #48106000052). Additional funding which supported background work done before this project started and closely related work was received from the New Jersey Agricultural Experiment Station (NJAES) and the US Department of Defense, Advanced Research Projects Agency, Office of Naval Research, University Research Initiative (Grant # N00014-92-J-1888, R ; Purpose: To expand the range of knowledge concerning what constitutes ?reasonable? groundwater on rates for water-soluble contaminants present in gasoline.