title: Production of electricity during wastewater treatment using a single chamber microbial fuel cell.
abstract: Microbial fuel cells (MFCs) have been used to produce electricity from different compounds, including acetate, lactate, and glucose. We demonstrate here that it is also possible to produce electricity in a MFC from domestic wastewater, while atthe same time accomplishing biological wastewater treatment (removal of chemical oxygen demand; COD). Tests were conducted using a single chamber microbial fuel cell (SCMFC) containing eight graphite electrodes (anodes) and a single air cathode. The system was operated under continuous flow conditions with primary clarifier effluent obtained from a local wastewater treatment plant. The prototype SCMFC reactor generated electrical power (maximum of 26 mW m(-2)) while removing up to 80% of the COD of the wastewater. Power output was proportional to the hydraulic retention time over a range of 3-33 h and to the influent wastewater strength over a range of 50-220 mg/L of COD. Current generation was controlled primarily by the efficiency of the cathode. Optimal cathode performance was obtained by allowing passive air flow rather than forced air flow (4.5-5.5 L/min). The Coulombic efficiency of the system, based on COD removal and current generation, was < 12% indicating a substantial fraction of the organic matter was lost without current generation. Bioreactors based on power generation in MFCs may represent a completely new approach to wastewater treatment. If power generation in these systems can be increased, MFC technology may provide a new method to offset wastewater treatment plant operating costs, making advanced wastewater treatment more affordable for both developing and industrialized nations.
authors.affiliation: Department of Civil and Environmental Engineering, The Penn State Hydrogen Energy, (H2E) Center, The Pennsylvania State University, University Park, Pennsylvania, USA.
authors.forename: Hong
authors.initials: H
authors.lastname: Liu
authors.forename: Ramanathan
authors.initials: R
authors.lastname: Ramnarayanan
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Logan
mesh_terms: D001674:Bioelectric Energy Sources; D019149:Bioreactors; D003246:Conservation of Energy Resources; D004560:Electricity; D005160:Facility Design and Construction; D010100:Oxygen / Q000032:analysis; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D010100:Oxygen