Enhanced electricity generation and water pressure tolerance using carbon black-based sintered filtration air-cathodes in microbial fuel cells

Abstract

Filtration air-cathode coupled electrochemical property and filtration can enhance the power generation and effluent quality of microbial fuel cell. Filtration membrane air-cathode modified by conductive carbon black as the catalyst is fabricated using the sintered method. The optimal content of carbon black is 15% (by weight with active carbon). The conductivity (19.8 ± 0.6 mS cm−1) is 38.6 times higher than the control (0.5 ± 0.06 mS cm−1, activated carbon, no carbon black). The cathode produces the highest maximum power density of 1330 ± 52 mW m−2, which is 90% higher than that of the control (700 ± 5 mW m−2). The reject rate of the final anolyte total chemical oxygen demand is 55.4 ± 2.4%, which is 28% higher than that of the control (43.2 ± 1.1%). With different water pressure, the sintered filtration air-cathode with 15% carbon black exhibits the more stable electrochemical performances. The porosity is stable before and after adding of 30 kPa water pressure. These results demonstrate that the novel sintered filtration cathode possesses higher water pressure tolerance and higher quality effluent compared to those of the control cathode.