In Colorado alone there are over 30,000 abandoned mines. Heavy metals emanating from former mine sites are a major threat to water resources. Sulfate-reducing bacteria (SRB) present a natural way to reverse the damage caused by acid mine drainage. SRB are able to "breathe" sulfate, forming sulfides, which in turn bind to metals and remove them from the water. When applied in a permeable reactive zone (PRZ), mine drainage is treated passively (no energy inputs required- ideal for remote sites): acidic metal laden water enters the barrier and exits as neutral metal free water. The purpose of this research is to optimize the performance of PRZs through the application of optimized inocula. Our experiments have demonstrated that inocula has a significant impact on performance. We have developed a suite of molecular tools, including denaturing gradient gel electrophoresis (DGGE), single stranded conformation polymorphism (SSCP), and real time PCR in order to characterize the microbial communities active in PRZs. This research is in collaboration with Dr. Kenneth Reardon (CSU, Chemical Engineering) and Dr. Linda Figueroa (Colorado School of Mines, Environmental Engineering and Science). Most current work is in the characterization of the microbial communities active at the Luttrell and Peerless Jenny King SR-PRZs near Helena, MT, and the Leviathan Ethanol sulfate-reduciong bioreactor near Markleeville, CA.
|Dr. Pruden sampling the Peerless Jenny King combination wetland / SR-PRZ.||
Passive treatment using sulfate-reducing bacteria (SRB) in a permeable reactive zone (PRZ).
Column experiment demonstrating effect of inoculum on removal of zinc.
Thank you to the David Reisman and the EPA Office of Research and Development Engineering Technical Support Center for financial support!
Students Working this Project:
Luciana P. Pereyra, Ph.D. Candidate
B.S. Food Engineering
Sage R. Hiibel, Ph.D. Candidate (Co-advisor with Dr. Reardon)
M.S. and B.S. Chemical Engineering,
April Tischer, B.S.
Environmental Engineering, Colorado State University
Kaileen Blanchard, B.S. Candidate
Chemical and Biological Engineering
Pruden, A., Messner, N.L., Pereyra, L.P., Hiibel, S., Hanson, R.E., and K.F. Reardon. Role of Inoculum in the Performance of Sulfate-Reducing Columns Remediating Heavy Metals. Water Research (submitted April, 2006).
Hong, H., Inman, L.Y., Pruden, A., and K.F. Reardon. Comparison of CE-SSCP and DGGE for Monitoring a Complex Microbial Community Remediating Mine Drainage. J. Microbiol. Meth. (in preparation, submission expected August, 2006).
Hong, H., Inman, L.Y., Pruden, A., and K.F. Reardon. Comparison of microbial communities present in columns with varying sulfate-reducing activities remediating mine drainage. Water Res. (in preparation, submission expected September, 2006).
Pereyra, L.P., Pruden, A., Hiibel, S.R., Inman, L.Y., Kashani, N., Reardon, K.F., and D. Reisman. Microbiology of Two Sulfate-Reducing Field Bioreactors Used for the Remediation of Mining Influenced Water. ASCE Environmental and Water Resources Institute (EWRI) World Environmental and Water Resources Conference, May 21-25, 2006, Omaha, NE.
Pereyra, L.P., and A. Pruden. Comparison of Inocula Applied in the Remediation of Heavy Metals by Sulfate Reduction. 3 rd Annual WEF/AWWA Regional Student Conference, May 19 th, 2006, Colorado State University, Fort Collins, CO. ( won 1 stprize for student poster presentations).
Pruden, A., Pereyra, L.P., Hiibel, S., Reardon, K.F., and D. Reisman. Microbiology of Sulfate-Reducing Passive Treatment Systems. 7 th International Conference on Acid Rock Drainage (ICARD), March 26-29, 2006, St. Louis, MO.
Hiibel, S.R., Pereyra, L.P., Pruden, A., and K.F. Reardon. Microbiological Comparison of Two Field-Scale Sulfate-Reducing Permeable Reactive Zones Treating Mine Drainage. 26th Annual American Geophysical Union Hydrology Days, March 20 - 22, 2006, Colorado State University, Fort Collins, CO.
Pereyra, L.P., Hanson, R.E., Hiibel, S., Pruden, A., and K.F. Reardon. Comparison of Inocula Applied in the Remediation of Acid Mine Drainage by Sulfate Reduction. American Society for Mining Reclamation (ASMR), June 18-23, 2005 , Breckenridge , CO. (won 2nd place for student presentation)
Pruden, A., Hong, H., Inman, L.Y., Logan , M.V., Sans, C., Ahmann, D., Figueroa, L.A. and K. F. Reardon. Microbial Characterization of Sulfate-Reducing Columns Remediating Acid Mine Drainage. American Society for Mining Reclamation (ASMR), June 18-23, 2005, Breckenridge, CO.
Pereyra, L.P., and A. Pruden. Comparison of Inocula Applied in the Remediation of Heavy Metals by Sulfate Reduction. WEF/AWWA Student Conference, May 18, 2005, University of Wyoming, Laramie , WY.
N.L. Messner, L.P. Pereyra, A. Pruden, K. Reardon, and C. Sans-Mazón. Effect of inocola on Heavy Metal Removal by Sulfate-Reducing Columns. 11 th Annual Conference on Tailings and Mine Waste, October 10-13, 2004 , Vail, CO. Balkema Publishers, Leiden , Netherlands , pp. 213-221.
Hong, H., Pruden, A., Inman, L., Walston, K., Logan , M., Reardon, K.F., and Figueroa, L. Molecular Characterization of Microbial Communities Present in Sulfate-Reducing Permeable Reactive Zones Remediating Heavy Metals. Mine Design, Operation, and Closure Conference, April 27-29, 2004 , Polson, MT.
Pruden, A., Hong, H., Logan, M., Inman, L., Sans Mazón, C., Reardon, K.F. and Figueroa, L.A. Microbial community dynamics of sulfate-reducing permeable reactive zones remediating heavy metals. 10th International Symposium on Microbial Ecology, August 22-27, 2004, Cancun, Mexico. p. 229.
Messner, N.L., H. Hong, L.Y. Inman, K.R. Walston, A. Pruden, N.M. DuTeau, K.F. Reardon M. Logan, D. Ahmann, and L. Figueroa. Microbial Population Dynamics in Sulfate-Reducing Mine Drainage Treatment Systems. Battelle Conference on Remediation of Chlorinated and Recalcitrant Compounds, May 24-27, 2004 , Monterey , CA. p. E2.
Pereyra, L.P., Hanson, R.E., Messner, N.L., Pruden, A., and K.F. Reardon. The Optimization of Inocula for the Bioremediation of Acid Mine Drainage Using Sulfate Reduction, HSRC Annual Meeting, August 8-10, 2004, Colorado State University, Fort Collins, CO.
Hong, H., Pruden, A., Logan , M., Inman, L.Y., Sans, C., Reardon, K.F., and Figueroa, L.A. Microbial Analysis of Sulfate-Reducing Columns Remediating Heavy Metals. WEF/AWWA Student Conference, May 18, 2004, Colorado School of Mines, Golden, CO.