Continuous bioelectricity production and sustainable wastewater treatment in a microbial fuel cell constructed with non-catalyzed granular graphite electrodes and permeable membrane

摘要

Oxygen has been so far addressed as the most preferable terminal electron acceptor in thencathodes of microbial fuel cells (MFCs). However, to reduce the oxygen reduction overpotentialnat the cathode surface, eco-unfriendly and costly catalysts have been commonly employed.nHere, we pursued the possibility of using a high surface area electrode to reduce the cathodicnreaction overpotential rather than the utilization of catalyzed materials. A dual chambered MFCnreactor was designed with the use of graphite-granule electrodes and a permeable membrane.nThe performance of the reactor in terms of electricity generation and organic removal rate wasnexamined under a continuous-feed manner. Results showed that the maximum volumetricnpower of 4.4 ^ 0.2W/m3nnet anodic compartment (NAC) was obtained at a current densitynof 11 ^ 0.5A/m3nNAC. The power output was improved by increasing the electrolyte ionicnstrength. An acceptable effluent quality was attained when the organic loading rate (OLR)nof 2 kgCOD/m3nNAC d was applied. The organic removal rate seemed to be less affectednby shock loading. Our system can be suggested as a promising approach to make MFC-basedntechnology economically viable for wastewater treatment applications. This study showsnthat current generation can be remarkably improved in comparison with several othernstudies using a low-surface-area plain graphite electrode.