Impact of Ethanol on Benzene Plume Lengths: Microbial and Modeling Studies Academic Article uri icon


  • Recent legislation in several states has called for the removal of methyl tert-butyl ether (MTBE) from gasoline. In order to comply with Federal Clean Air Act requirements for carbon monoxide and ozone attainment, ethanol is being considered as a replacement for MTBE. The objective of this study is to evaluate the potential impact of ethanol on benzene plume lengths in subsurface environments following accidental spills of ethanol-blended gasoline. Two types of studies were conducted here. First, laboratory studies were performed using a pure culture indigenous to a gasoline-contaminated aquifer to evaluate the effect of ethanol on the rate of benzene biodegradation under aerobic conditions. Results from microbial studies showed that the biodegradation of 25 mg/L benzene was severely inhibited in the presence of 25 mg/L ethanol. While the enzymes responsible for benzene biodegradation by the culture were inducible, ethanol degradation appeared to be constitutive. Second, a two-dimensional model was developed to quantify the impact of ethanol on benzene plume lengths using weighted-average aerobic and anaerobic biodegradation rates for benzene in the presence and absence of ethanol. Model simulations indicated that benzene plume lengths are likely to increase by 16-34% in the presence of ethanol.

published proceedings

  • Journal of Environmental Engineering

author list (cited authors)

  • Deeb, R. A., Sharp, J. O., Stocking, A., McDonald, S., West, K. A., Laugier, M., ... Alvarez-Cohen, L.

citation count

  • 39

complete list of authors

  • Deeb, Rula A||Sharp, Jonathan O||Stocking, Andrew||McDonald, Shane||West, Kimberlee A||Laugier, Maryline||Alvarez, Pedro JJ||Kavanaugh, Michael C||Alvarez-Cohen, Lisa

publication date

  • September 2002