Methyl tert-butyl ether (MTBE) is a gasoline additive that has contributed greatly to reducing emissions and improving air quality. However, its high water solubility allows it to spread rapidly in groundwater when underground storage tanks leak. Thus, it has become a significant threat to drinking water supplies. While MTBE is not known to be toxic, other major gasoline components are: (benzene, toluene, ethylbenzene, and xylenes or BTEX). Biodegradation is a promising approach to MTBE and BTEX clean-up. However, several studies have shown that BTEX interferes with MTBE biodegradation both in laboratory experiments and in the field. On the other hand, other experiments (Pruden and Suidan, 2004) have demonstrated that this is not always the case. The purpose of this research is to better understand BTEX inhibition of MTBE biodegradation through investigating the microbial community dynamics of inhibition. We are currently conducting a pilot-scale study of a surface-flow wetland at the SunCor oil refinery, Denver, CO. Surface-flow wetlands have high microbial activity and also provide a complex environment for multiple microbial niches and thus may facilitate simultaneous biodegradation of MTBE and BTEX.

Thank you to SunCor Oil Refinery and CONACYT for supporting this research!!!

Student working on this project:

Maria Elena Raynal Gutierrez, Ph.D. Candidate

M.S. U Illinois Urbana-Champaign, Environmental Engineering. 2004.
B.S. Civil Engineering, Universidad de las Americas, Mexico, 2001.


at CSU:

Raynal, M., Sale, T., and A. Pruden. MTBE biodegradation in the presence of BTEX by two distinct consortia under batch and semi-batch conditions. Biodegradation (in preparation, submission expected September, 2006).

Raynal, M., Sale, T., and A. Pruden. Wetland Treatment of MTBE Contaminated Groundwater at a Local Refinery. M. ASCE Environmental and Water Resources Institute (EWRI) World Environmental and Water Resources Conference, May 21-25, 2006, Omaha, NE.

Raynal, M., Pruden, A., and T. Sale. Treatment of MTBE and BTEX at a Local Refinery: Bench and Field Studies . 26th Annual American Geophysical Union Hydrology Days, March 20 - 22, 2006, Colorado State University, Fort Collins, CO.

Pruden, A., and Pei, R. Microbial Community Dynamics of BTEX Inhibition of MTBE and TBA Biodegradation. 10th International Symposium on Microbial Ecology, August 22-27, 2004 , Cancun , Mexico .

Pei, R., Anurita, and Pruden, A. Microbial Community Dynamics of MTBE and BTEX Degradation. Hydrology Days, March 10-12, 2004 , Colorado State University, Fort Collins, CO.

Pei, R., Anurita, and A. Pruden. Microbial Community Dynamics During BTEX Inhibition of MTBE and TBA Biodegradation. WEF/AWWA Student Conference, May 18, 2004 , Colorado School of Mines, Golden, CO.

Select Publications from Dr. Pruden's dissertation research with Dr. Suidan at University of Cincinnati.

Pruden, A., M.A. Sedran, M.T. Suidan, and A.D.Venosa. (2005). Anaerobic Biodegradation of Methyl tert-Butyl Ether Under Iron-Reducing Conditions. Water Environ. Res. (in press for March/April 2005, vol. 77 No. 2).

Pruden, A., and M.T. Suidan. (2004). Effect of Benzene, Toluene, Ethyl Benzene, and p-Xylene (BTEX) on the Biodegradation of Fuel Oxygenates Methyl tert-Butyl Ether (MTBE) and tert-Butyl Alcohol (TBA) by Pure Bacterial Culture UC1. Biodegradation 15(4): 213-227.

Sedran, M.A., Pruden, A., Wilson , G.J., Suidan, M.T., and A.D. Venosa. (2004). Biodegradation of Methyl tert-Butyl Ether and BTEX at Varying Hydraulic Retention Times. Water. Env. Res.76(1): p47-55.

Pruden, A., M.A. Sedran, M.T. Suidan, and A.D. Venosa. (2003). Biodegradation of MTBE and BTEX in an Aerobic Fluidized-Bed Reactor. Water Sci. Technol. 47 (9):123–128.

Sedran, M.A., A. Pruden, G.J. Wilson, M.T. Suidan, A.D. Venosa. (2002). Effect of BTEX on the Degradation of MTBE and TBA by a Mixed Bacterial Consortium. ASCE J. Environ. Eng. 128: 830-835.

Wilson , G.J., Pruden, A., Suidan, M.T., and A.D. Venosa. (2002). Biodegradation Kinetics of MTBE in Laboratory Batch and Continuous Flow Reactors. ASCE J. Environ. Eng. 128: 824-829.

Pruden, A., M.T. Suidan, J. Morrison, and A.D. Venosa. (2001). Denaturing Gradient Gel Electrophoresis Analysis of a Methyl tert-Butyl Ether Degrading Culture Applied in a Membrane Bioreactor. Water Sci. Technol: Water Supply 2:207-212.

Pruden, A., G.J. Wilson, M.T. Suidan, and A.D. Venosa. (2001). Biodegradation of Methyl tert-Butyl Ether Under Various Substrate Conditions. Environ. Sci. Technol.35(21):4235-4241.

Wilson , G.J., A. Pruden, M.T. Suidan, A.D. Venosa. (2001). Aerobic Biodegradation of Gasoline Oxygenates MTBE and TBA. Water Sci. Technol. 43(2):277-284.