Chromium Remediation and Recovery Using Microbial Fuel Cell Technology

University Of Southern California, Los Angeles CA

Investigators

Abstract

CBET- 0826198 Nealson This proposal involves the application of microbial fuel cell (MFC) technology for the removal of chromium (Cr), a carcinogenic metal commonly found in the soils and aquifers of polluted locations, such as brownfield or Superfund sites. The proposed approach has unique advantages over the existing treatment techniques it would capitalize on the metal reducing capabilities of Shewanella in the cathode compartment of a MFC to remove the soluble and mobile Cr (VI) species through reductive precipitation while providing supplemental electrical energy to the system. Preliminary studies in the PI's lab have demonstrated the ability of prototype systems to effectively reduce and remove hexavalent chromium species from solution. The proposal will develop a microbial fuel cell to use organisms capable of reducing hexavalent chromium to form an insoluble precipitate within the cathode compartment. The research will result in a greater understanding of the metal reducing ability and biological pathways in metal reducing bacteria for hexavalent chromium species. The results of this study may be also extended to other pollutants. Until now, the focus of applied MFC technology has been wastewater treatment by microbial consortia in the anodic compartment. Application of MFCs to heavy metal remediation will yield new avenues of research with respect to fuel cell biocathodes and MFC modeling. This research will result in a greater understanding of the metal reducing ability and biological pathways found in metal reducing bacteria (MRB). Members of the Shewanella genus will be used as our model organisms because the genomes of strains to be utilized have already been sequenced. This will be of great importance in future genomic and proteomic studies; discoveries regarding metal reduction pathways and functionality can be extended to other MRB species and communities. The results of this study may be also extended to other pollutants such as arsenic, uranium, and technetium. Development of the proposed MFC technology will provide highly beneficial and desirable interdisciplinary collaboration focusing on protecting the environment and public health. In addition to being an effective tool for metal remediation and recovery, the development of the MFC system as proposed would be an exciting educational tool for both general audiences and students of multiple disciplines