Effect of influential factors on microbial growth and the correlation between current generation and biomass in an air cathode microbial fuel cell

Microbial biomass in a microbial fuel cell (MFC) was determined at varied external resistances and temperatures, and the current generations were correlated with biomass concentration. MFC operation with wastewater generated the highest current of 0.23 mA at 300 Ω compared with 100 Ω (0.22 mA) and 1000 Ω (0.18 mA). The microbial biomass (0.091 mg-protein/cm2) on the anode with 100 Ω was higher than the other resistances. With growth media, current and biomass density were increased due to high strength electrolyte and nutrient. The MFCs with higher current generation contained a more amount of biomass on an anode electrode. The highest biomass growth rate with growth media was 1.307 × 10−4 mg-protein/hr·cm2 at 30 °C (with 300 Ω), which was about 2 times higher than with wastewater. In linear regression, current generation is expected to increase by about 3 times as the biomass is doubled on the anode electrode.