Production of Electricity during Wastewater Treatment Using a Single Chamber Microbial Fuel Cell

• Published in: Environmental science & technology Vol. 38; no. 7; pp. 2281 - 2285
• Main Authors: Liu, Hong, Ramnarayanan, Ramanathan, Logan, Bruce E
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.04.2004
• Subjects: Advanced Wastewater Treatment; Air flow; Applied sciences; Bioelectric Energy Sources; Biological and medical sciences; Biological treatment of waters; Biomass; Bioreactors; Biotechnology; Chemical oxygen demand; Conservation of Energy Resources; Electricity; Energy; Environment and pollution; Exact sciences and technology; Facility Design and Construction; Fuel cells; Fundamental and applied biological sciences. Psychology; Industrial applications and implications. Economical aspects; Natural energy; Other wastewaters; Oxygen - analysis; Pollution; Technology; Waste Disposal, Fluid - methods; Wastewaters; Water treatment; Water treatment and pollution; Energy recovery; Microbial biomass; Optimization; Sewage treatment plant; Biological purification; Domestic waste water; Bioreactor; Microbial electrode; Biochemical fuel cell; Physicochemical purification; Electric power production; Waste water purification; Performance
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es034923g

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 at the 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.