On-site performance evaluation of a 1,000-litre microbial fuel cell system using submergible multi-electrode modules with air-cathodes for sustainable municipal wastewater treatment and electricity generation

The reliability of a microbial fuel cell (MFC) system was tested on an industrial scale by operating a 1,000-litre single-chamber system under real conditions at a municipal wastewater treatment plant (WWTP) over a 6-month period. Submergible multi-electrode modules with largescale grid-segmented gas diffusion cathodes with activated carbon as a catalyst were used. Maximum power densities normalised to the cathode area were above 100 mW m(Cat)(-2) . Fluctuating chemical and physical wastewater characteristics of the influent had reversible effects on MFC performance in terms of energetic efficiency. Thereby, the composition of the chemical oxygen demand (COD) fractions changes only insignificantly and the concentration of readily biodegradable (S-S) required for the enhanced biological phosphorus removal (EBPR) process or upstream denitrification was reduced by 41 +/- 10 mg L-1 (37 +/- 2% of inflow S-S).

Automated summary

The reliability of a microbial fuel cell (MFC) system on an industrial scale was tested in a 1,000-litre single-chamber system at a municipal wastewater treatment plant (WWTP). The use of submergible multi-electrode modules with largescale grid-segmented gas diffusion cathodes with activated carbon as a catalyst resulted in power densities above 100 mW m(Cat)(-2). Fluctuating chemical and physical wastewater characteristics had reversible effects on the MFC performance in terms of energetic efficiency.