Impact of Ethanol on the Natural Attenuation of MTBE in a Normally Sulfate-Reducing Aquifer

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• 作者：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
• 刊名：Environmental Science & Technology
• 出版年：2007
• 出版时间：March 15, 2007
• 年：2007
• 卷：41
• 期：6
• 页码：2015 - 2021
• 全文大小：516K
• 年卷期：v.41,no.6(March 15, 2007)
• ISSN：1520-5851

文摘

Side-by-side experiments were conducted in an aquifercontaminated with methyl-tert-butyl ether (MTBE) at a formerfuel station to evaluate the effect of ethanol release onthe fate of pre-existing MTBE contamination. On one side,for ~9 months we injected groundwater amended with1-3 mg/L benzene, toluene, and o-xylene (BToX). On theother side, we injected the same, adding ~500 mg/ L ethanol.The fates of BToX in both sides ("lanes") were addressedin a prior publication. No MTBE transformation wasobserved in the "No Ethanol Lane." In the "With EthanolLane", MTBE was transformed to tert-butyl alcohol (TBA)under the methanogenic and/or acetogenic conditions inducedby the in situ biodegradation of the ethanol downgradientof the injection wells. The lag time before onset of thistransformation was less than 2 months and the pseudo-first-order reaction rate estimated after 7-8 months was0.046 d^-1. Our results imply that rapid subsurfacetransformation of MTBE to TBA may be expected insituations where strongly anaerobic conditions are sustainedand fluxes of requisite nutrients and electron donorsallow development of an active acetogenic/methanogeniczone beyond the reach of inhibitory effects such asthose caused by high concentrations of ethanol.