Bacterial production stimulated across the zone of influence of a ground water circulation well in a BTEX-contaminated aquifer

Authors

Michael T. Montgomery, U.S. Naval Research Laboratory
Barry J. Spargo, U.S. Naval Research Laboratory
James G. Mueller, URS Corporation
Richard B. Coffin, U.S. Naval Research Laboratory
David C. Smith, University of Rhode Island
Thomas J. Boyd, U.S. Naval Research Laboratory

Document Type

Article

Date of Original Version

1-1-2002

Abstract

Benzene, toluene, ethylbenzene, and xylene (BTEX) hydrocarbons are typically the most abundant carbon source for bacteria in gasoline-contaminated ground water. In situ bioremediation strategies often involve stimulating bacterial heterotrophic production in an attempt to increase carbon demand of the assemblage. This may, in turn, stimulate biodegradation of contaminant hydrocarbons. In this study, ground water circulation wells (GCWs) were used as an in situ treatment for a fuel-contaminated aquifer to stimulate bacterial production, purportedly by increasing oxygen transfer to the subsurface, circulating limiting nutrients, enhancing bioavailability of hydrocarbons, or by removing metabolically inhibitory volatile organics. Bacterial production, as measured by rates of bacterial protein synthesis, was stimulated across the zone of influence (ZOI) of a series of GCWs. Productivity increased from ∼ 102 to > 105 ng C/L hour across the ZOI, suggesting that treatment stimulated overall biodegradation of carbon sources present in the ground water. However, even if BTEX carbon met all bacterial carbon demand, biodegradation would account for <4.3% of the total estimated BTEX removed from the ground water. Although bacterial productivity measurements alone cannot prove the effectiveness of in situ bioremediation, they can estimate the maximum amount of contaminant that may be biodegraded by a treatment system.

Publication Title, e.g., Journal

Ground Water Monitoring and Remediation

Volume

22

Issue

3

Citation/Publisher Attribution

Montgomery, Michael T., Barry J. Spargo, James G. Mueller, Richard B. Coffin, David C. Smith, and Thomas J. Boyd. "Bacterial production stimulated across the zone of influence of a ground water circulation well in a BTEX-contaminated aquifer." Ground Water Monitoring and Remediation 22, 3 (2002). doi: 10.1111/j.1745-6592.2002.tb00763.x.