DescriptionBiogeochemical processes alter the physical and chemical properties in the subsurface, and efficient monitoring of these changes is important for successful implementation of soil and groundwater remediation. Electrical geophysical methods offer spatially extensive and densely sampled information on variations in the physiochemical properties of subsurface at various scales. The focus of this dissertation is the development of electrical geophysical monitoring approaches sensitive to microbial sulfate reduction in porous media, sulfate-reducing bacteria activity, and mineral precipitation in porous media. This research suggests the feasibility of using electrical geophysical techniques in monitoring environmental contamination remediation. In the first research topic, electrodic potential (EP), in conjunction with spectral induced polarization (SIP) and self-potential (SP) measurements were used for monitoring microbial sulfate reduction in a silica beads column saturated with natural river water. Significant EP signals were recorded and correlated with HS- near multiple sensing electrodes, no significant SP signals were observed. The SIP responses were linked with overall microbial activity in the column. Joint use of multiple electrical geophysical methods can be applied to capture the spatiotemporal variability in microbial sulfate reduction in a porous medium. The second research topic examined the sensitivity of dielectric spectroscopy to sulfate-reducing bacteria (Desulfovibrio vulgaris) growth in cellular suspensions. Low frequency dielectric properties of D. vulgaris were studied using a high quality two-electrode system over frequencies 20 Hz to 1 MHz. The dielectric permittivity, real and imaginary parts of complex conductivity increased for higher concentrations of bacteria at frequencies <10 kHz. Reduced permittivity and conductivity were found as bacteria grew from earlier growth stage to later growth stage. The third research topic investigated the evolution of urea mediated calcium carbonate mineral precipitation and ion adsorption using SIP in silica gel column. Both real and imaginary parts of complex conductivity increased with rising hydroxide ion concentration during urea hydrolysis. Distinct decreases in complex conductivity were observed during calcium carbonate precipitation. Significant dependence of imaginary conductivity on pH in silica gel was found in a separate study. The results suggest the control of pH and calcite precipitation on the polarization response in silica gel in.