Synchronously electricity generation and degradation of biogas slurry using microbial fuel cell

Abstract

Microbial fuel cell (MFC) with biogas slurry (BS) of corn stover as anode substrate was studied in this paper to solve the problem of the accumulation of wastewater generated from biogas plants. Using domestic water (DW) as inoculum, the BS MFCs could start quickly and remain a stable power generation (622.7 ± 30.3 mV) for 10 days. The maximum power density of the BS MFC was 296 mW/m2 when the external resistance varied to 200 Ω. The removal rate of chemical oxygen demand (COD) and ammonium nitrogen was 72.0% and 43.9% at the 16th day, respectively. The microbial community analysis indicated that the microbes in anode solution was mainly from BS, belonging to hydrolyzed bacteria. Meanwhile, the electroactive microbial community mainly coming from DW was predominated in biofilm. Therefore, MFC can effectively degrade organics in the BS and generate electricity, providing a new approach for BS utilization.