The research presented herein addresses the need to explore strategies for the cost-effective development of permeable reactive barriers in the deep subsurface. The metabolic capabilities of Dissimilatory Metal-Reducing Bacteria (DMRB) appear to have the potential to create zones of reduced indigenous metals (e.g. ferrous iron) in the path of a groundwater contaminant plume forming redox-reactive barriers. Microbially reduced iron can reductively dechlorinate organic pollutants, reduce nitroaromatics, and/or precipitate heavy metals and radionuclides from contaminated waters. Starvation of bacteria has shown to enhance bacterial transport and distribution through porous media, thus providing a possible means for the delivery of bacteria into the subsurface. To demonstrate the potential of starved bacteria for in situ metal-reduction, starved bacteria were resuscitated of starved bacteria for in situ metal-reduction, starved bacteria were resuscitated with surface associated iron minerals in batch and column experiments. In both batch and column studies, the microbially produced surface-associated Fe(II) reduced Cr(VI), a common groundwater contaminant, to Cr(III), Cr(III) precipitated on the existing surfaces, forming stable end products and thereby eliminating the chromium compounds from the water phase.
展开▼
