The influence of various carbon anodes; graphite, sponge, paper, cloth, felt, fiber, foam and reticulated vitreous carbon (RVC); on microbial fuel cell (MFC) performance is reported. The feed was brewery wastewater diluted in domestic wastewater. Biofilms were grown at open circuit or under an external load. Microbial diversity was analysed as a function of current and anode material. The bacterial community formed at open circuit was influenced by the anode material. However at closed circuit its role in determining the bacterial consortia formed was less important than the passage of current. The rate and extent of organic matter removal were similar for all materials: over 95% under closed circuit. The biofilm in MFCs working at open circuit and in the control reactors, increased COD removal by up to a factor of nine compared with that for baseline reactors. The average voltage output was 0.6 V at closed circuit, with an external resistor of 300 kΩ and 0.75 V at open circuit for all materials except RVC. The poor performance of this material might be related to the surface area available and concentration polarizations caused by the morphology of the material and the structure of the biofilm. Peak power varied from 1.3 mW m-2 for RVC to 568 mW m-2 for graphite with biofilm grown at closed circuit.
Bibliographical noteFunding Information:
Acknowledgments The support of the European Union for Transfer of Knowledge award (MTKD-CT-2004-517215) for biological fuel cells, the EPSRC and the Spanish Ministry of Science and Innovation (MICINN ENE2006-09395) are acknowledged. Mrs. Fiona L. Read and Mr. Alberto Alcolea are acknowledged as well for their support in microbial analysis and SEM.
- Bacteria selection
- Carbon materials
- Microbial fuel cell
- Wastewater treatment
ASJC Scopus subject areas
- Applied Microbiology and Biotechnology