HR: 17:50h
AN: NS44A-05    [Abstracts]
TI: Geoelectrical Signatures Of Microbial Stimulated Mineralization
AU: * Personna, Y R
EM: personna@pegasus.rutgers.edu
AF: Department of Earth and Environmental Sciences, Rutgers University, 101 Warren Street, Newark, NJ 07102, United States
AU: Ntarlagiannis, D
EM: dimntar@pegasus.rutgers.edu
AF: Department of Earth and Environmental Sciences, Rutgers University, 101 Warren Street, Newark, NJ 07102, United States
AU: Slater, L
EM: lslater@andromeda.rutgers.edu
AF: Department of Earth and Environmental Sciences, Rutgers University, 101 Warren Street, Newark, NJ 07102, United States
AU: O Brien, M
EM: mikeob2@pegasus.rutgers.edu
AF: Department of Earth and Environmental Sciences, Rutgers University, 101 Warren Street, Newark, NJ 07102, United States
AU: Hubbard, S
EM: SSHubbard@lbl.gov
AF: Lawrence Berkeley National Laboratory, Earth Science Division, 1 Cyclotron Road MS 90- 1116, Berkeley, CA 94720, United States
AU: Williams, K H
EM: KHWilliams@lbl.gov
AF: Lawrence Berkeley National Laboratory, Earth Science Division, 1 Cyclotron Road MS 90- 1116, Berkeley, CA 94720, United States
AU: Williams, K H
EM: KHWilliams@lbl.gov
AF: Department of Environmental Science, Policy and Management, University of California, Berkeley, CA 94720, United States
AB: Bioremediation techniques are commonly utilized to address soil and groundwater contamination due to acid- mine drainage, industrial sources, and government nuclear weapon programs. One critical component of these efforts is the real time, spatially accurate monitoring of the remediation processes. For this reason non-invasive high resolution geophysical methods have been employed in the recent years to elucidate system transformations occurring during bioremediation. In our study, we performed laboratory column experiments to investigate the geoelectrical response of microbe-mediated iron sulfide (FeS) precipitation accompanying stimulated sulfate-reduction; a bioremediation technique currently utilized for the sequestration of heavy metals in the subsurface. In order to monitor the biomineralization process, we used two geoelectrical methods - induced polarization (IP) and self-potential (SP) - in conjunction with conventional geochemical measurements. The IP data showed significant anomalies associated with ongoing FeS mineralization accompanying microbial activity. The magnitude of the IP response can be considered a proxy for the mass of minerals accumulating in the pore space and may provide insight into the aggregation state of the mineralization. Additionally, strong SP anomalies developed during the mineralization as a result of the continuous redox state changes following the microbial induced mineral formation. Visibly black precipitates accumulated with the column indicating FeS precipitation, and high H2S content confirmed the observed geochemical and geophysical data. Overall, the results suggest that the IP and SP methods can be used to monitor the progress of the microbial induced mineralization process associated with the precipitation of insoluble metal sulfides, and indirectly monitor the microbial activity within the subsurface. These methods can be valuable tools to increase the efficiency of bioremediation techniques.
DE: 0416 Biogeophysics
SC: Near-Surface Geophysics [NS]
MN: 2007 Joint Assembly