ERG members monitor microbial dynamics in porous media using spectral induced polarization

In a new paper, ERG members Adrian Mellage, Christina Smeaton, Fereidoun Rezanezhad and Philippe Van Cappellen, together with colleagues from Technion and University of Delaware, describe the results of a fully saturated sand-filled column reactor experiment where the growth of the bacterium Shewanella oneidensis during nitrate reduction to ammonium is monitored using spectral induced polarization (SIP). They demonstrate that the geophysical signals are not only sensitive to the changing cell density but also record changes in surface charging properties of the cells resulting from toxic stress due to nitrite accumulation. The study represents an important step toward the application of SIP as a non-destructive method to monitor in situ microbial growth dynamics in the subsurface. The paper was published in the journal Near Surface Geophysics and can be accessed here.