Investigation on influential factors in electricity generation of microbial fuel cell

The output power and resistance were evaluated to investigate the effects of pH, substrate concentration, electrode spacing and electrolyte addition on the electricity generation of direct microbial fuel cell. The results showed that output power was much affected by pH. The optimal pH value was 7.5. The output power increased with the substrate concentration. It could be improved with the decrease of resistance as the electrode spacing decreased. When electrode spacing was decreased to 2 cm, the maximum power density was 700 mW/m², the resistance 80 Ω, and the coulomb efficiency 7.7%. PBS as the electrolyte was much better than NaCl on power improvement When PBS was 100 mmol/L, the maximum power density was 922 mW/m², the resistance 70 Ω, and the coulomb efficiency 11.5%.