Impact of ethanol on the natural attenuation of MTBE in a normally sulfate-reducing aquifer

Doug Mackay, Nick De Sieyes, Murray Einarson, Kevin Feris, Alex Pappas, Isaac Wood, Lisa Jacobson, Larry Justice, Mark Noske, John Wilson, Cherri Adair, Kate Scow

Research output: Contribution to journalArticlepeer-review

33 Scopus citations

Abstract

Side-by-side experiments were conducted in an aquifer contaminated with methyl-tert-butyl ether (MTBE) at a former fuel station to evaluate the effect of ethanol release on the fate of pre-existing MTBE contamination. On one side, for ∼9 months we injected groundwater amended with 1-3 mg/L benzene, toluene, and o-xylene (BToX). On the other side, we injected the same, adding ∼500 mg/L ethanol. The fates of BToX in both sides ("lanes") were addressed in a prior publication. No MTBE transformation was observed in the "No Ethanol Lane." In the "With Ethanol Lane", MTBE was transformed to tert-butyl alcohol (TBA) under the methanogenic and/or acetogenic conditions induced by the in situ biodegradation of the ethanol downgradient of the injection wells. The lag time before onset of this transformation was less than 2 months and the pseudo-first-order reaction rate estimated after 7-8 months was 0.046 d-1. Our results imply that rapid subsurface transformation of MTBE to TBA may be expected in situations where strongly anaerobic conditions are sustained and fluxes of requisite nutrients and electron donors allow development of an active acetogenic/methanogenic zone beyond the reach of inhibitory effects such as those caused by high concentrations of ethanol.

Original languageEnglish
Pages (from-to)2015-2021
Number of pages7
JournalEnvironmental Science and Technology
Volume41
Issue number6
DOIs
StatePublished - 15 Mar 2007

Fingerprint

Dive into the research topics of 'Impact of ethanol on the natural attenuation of MTBE in a normally sulfate-reducing aquifer'. Together they form a unique fingerprint.

Cite this