Polypropylene biofilm carrier and fabricated stainless steel mesh supporting activated carbon: Integrated configuration for performances enhancement of microbial fuel cell

Abstract

The mass transfer resistance at the anode and the reduction of oxygen at the cathode are currently perceived as two major bottlenecks of microbial fuel cells. To overcome these issues, an integrated configuration was developed for performances enhancement on simultaneous bioelectricity generation and wastewater treatment in single chamber up-flow membrane-less microbial fuel cell (UFML-MFC). Polypropylene biofilm carriers were used as anodic packing materials and fabricated stainless steel mesh holder supporting activated carbon flakes (CF/SM) was employed as biocathode configuration in this study. The employments of polypropylene carriers and CF/SM enhanced not only the active surface area and microbial adhesion, but also the mass transfer of MFC system. The maximum output voltage, power and current generation achieved in this system were 615 mV, 162.59 mW/m2 and 468.74 mA/m2, respectively. In terms of wastewater treatment performance, UFML-MFC achieved 85.6% and 95.7% of COD and NH4+ removal, respectively. The COD reduction in closed circuit was 9.87% better than open circuit due to stimulation of electrochemical-active bacteria for electron transfer to the anode, which favoured organic matter degradation. The enrichment of electrogenic bacteria at A3, which was largest electrode spacing (23 cm) in the system resulted a higher voltage and power output compared to A1 (11 cm) and A2 (17 cm). Besides, the energy performances of this MFC system were also evaluated based on NERs (1.074 kWh/kg COD), NERv (22.86 Wh/m3) and CE (10.42%).