Carbon filtration cathode in microbial fuel cell to enhance wastewater treatment

• A homogeneous carbon filtration membrane was fabricated without using noble metals.
• Excellent effluent quality and power generation were achieved in the filtration MFC.
• The performance of filtration MFC kept relative stable during 20 days operation.

A homogeneous carbon membrane with multi-functions of microfiltration, electron conduction, and oxygen reduction catalysis was fabricated without using noble metals. The produced carbon membrane has a pore size of 553 nm, a resistance of 6.0 ± 0.4 Ω cm2/cm, and a specific surface area of 32.2 m2/g. After it was assembled in microbial fuel cell (MFC) as filtration air cathode, a power density of 581.5 mW/m2 and a current density of 1671.4 mA/m2 were achieved, comparable with previous Pt air cathode MFCs. The filtration MFC was continuously operated for 20 days and excellent wastewater treatment performance was also achieved with removal efficiencies of TOC (93.6%), NH4+–N (97.2%), and total nitrogen (91.6%). In addition, the carbon membrane was much cheaper than traditional microfiltration membrane, suggesting a promising multi-functional material in wastewater treatment field.