Meta-analysis of operational performance and response metrics of microbial fuel cells (MFCs) fed with complex food waste

This study reports on a meta-analysis covering the impact of design and operating factors on published MFC performance data to inform MFC research and implementations. Factors of substrate composition, operating phase, electrode material, configuration, and pre-treatments employed were considered. The meta-analysis results indicate that dual-chamber MFCs overall achieve 18% higher COD removal and 73% higher coulombic efficiencies over that of single-chamber MFCs. MFCs using a solid operating phase achieved >38% higher coulombic efficiencies than those using a liquid operating phase. Statistical analyses comparing brush vs flat surface anodes revealed that brush anodes can achieve 130% higher power density than flat surface anodes. The use of a platinum catalyst was found to improve power density, as opposed to catalyst-free cathodes. However, coulombic efficiency is less likely to be influenced by the catalyst used and more likely to be dependent on the inclusion of a membrane separator. The meta-analysis results indicate that even in the presence of expensive catalysts like platinum, membrane separators are of prime importance to maintain a stable MFC operation on a long-term basis and achieve high coulombic efficiency in an MFC. Results presented in this paper outline the impact of MFC design choices on performance and can be used to guide future MFC research. These findings can be beneficial for municipalities as it provides a pathway for future MFC design and optimization by analyzing critical associations between MFC response parameters and multiple varying factors.