Anaerobic biodegradation of iso-butanol and ethanol and their relative effects on BTEX biodegradation in aquifer materials

作者：Schaefer Charles E; Yang Xiaomin^*; Pelz Oliver; Tsaob David T; Streger Sheryl H; Steffan Robert J

来源：Chemosphere, 2010, 81(9): 1111-1117.

DOI：10.1016/j.chemosphere.2010.09.002

• Butanol
• Ethanol
• BTEX
• Biofuels
• Biodegradation
• Environment

Biologically produced iso-butanol is currently being considered as an additive in gasoline blends. To evaluate its potential environmental fate in groundwater aquifers, a laboratory microcosm study was performed to evaluate iso-butanol biodegradation under various anaerobic conditions (nitrate-reducing, sulfate-reducing and methanogenic). The impacts of iso-butanol on benzene, toluene, ethylbenzene, and total xylenes (BTEX) biodegradation were also assessed, and microcosms prepared using ethanol instead of iso-butanol were evaluated to provide a basis for comparison. Iso-butanol was biodegraded under all conditions studied, with an observed apparent first-order rate constant ranging from approximately 0.2 d(-1) (nitrate-reducing) to approximately 0.02 d(-1) (sulfate-reducing). Iso-butanol typically was degraded in a time frame that was shorter than or similar to BTEX compounds. Iso-butyric acid and trace levels of iso-butylaldehyde were identified as transient intermediates, and both of these compounds were subsequently degraded within the time frame of the experiments. Iso-butanol and ethanol were biodegraded in similar time frames under methanogenic conditions. Under sulfate-reducing conditions, isobutanol biodegradation initially proceeded more slowly than ethanol, and then increased to a rate greater than that observed for ethanol; this observation likely was due to the growth of iso-butanol degrading bacteria. Iso-butanol generally exhibited less adverse impacts on BTEX biodegradations than ethanol under the anaerobic conditions studied. In some cases, addition of iso-butanol enhanced the rate of TEX biodegradation.

• 出版日期2010-11