John M. Dietz

Date of Award


Document Type


Degree Name

Master of Science


Department of Systems Engineering and Management

First Advisor

Charles A. Bleckmann, PhD


This research determined the rate and extent of aerobic biodegradation of fuel oxygenates ethyl tert butyl ether (ETBE), tert amyl methyl ether (TAME), and ethyl alcohol (ethanol). Biodegradation was measured using gas chromatography (GC), respirometry, and biochemical oxygen demand (BOD) tests. Additionally, the research determined the effects of toluene on degradation rates. This microcosm study used a microbial consortium obtained from a petroleum refinery wastewater treatment facility. Respirometry data were collected from chambers containing pure oxygenates, or oxygenate/toluene mixtures. Samples were withdrawn periodically for GC analysis. Aerobic conditions were maintained in the chambers at all times. The five-day BOD test was conducted separately using Standard Methods. Degradation of oxygenates was compared to degradation of toluene, assuming first order decay. Across all experiments TAME degraded at 8.57% the rate of toluene. Similarly, ETBE degraded at 7.86% the rate of toluene. Ethanol was significantly faster, degrading at 158.26% the rate of toluene. GC and respirometry were the most suitable methods for measuring degradation. The BOD5 test provided acceptable results for toluene and ethanol, but not for the slower degrading oxygenates. Finally, the presence of toluene slowed the degradation of both ETBE and TAME.

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