Power generation from organic substrate in batch and continuous flow microbial fuel cell operations

Microbial fuel cells (MFCs) are biochemical-catalyzed systems in which electricity is produced by oxidizing biodegradable organic matters in presence of either bacteria or enzyme. This system can serve as a device for generating clean energy and, also wastewater treatment unit. In this paper, production of bioelectricity in MFC in batch and continuous systems were investigated. A dual chambered air-cathode MFC was fabricated for this purpose. Graphite plates were used as electrodes and glucose as a substrate with initial concentration of 30 g l(-1) was used. Cubic MFC reactor was fabricated and inoculated with Saccharomyces cerevisiae PTCC 5269 as active biocatalyst. Neutral red with concentration of 200 mu mol l(-1) was selected as electron shuttle in anaerobic anode chamber. In order to enhance the performance of MFC, potassium permanganate at 400 mu mol l(-1) concentration as oxidizer was used. The performance of MFC was analyzed by the measurement of polarization curve and cyclic volatmmetric data as well. Closed circuit voltage was obtained using a 1 K Omega resistance. The voltage at steady-state condition was 440 mV and it was stable for the entire operation time. In a continuous system, the effect of hydraulic retention time (HRT) on performance of MFC was examined. The optimum HRT was found to be around 7 h. Maximum produced power and current density at optimum HRT were 1210 mA m(-2) and 283 mW m(-2), respectively. (C) 2011 Elsevier Ltd. All rights reserved.