Milliliter-scale microbial fuel cell (MFC) fabricated by polyethersulfone (PES) hollow fiber membrane

Microbial fuel cell (MFC) is a technology of increasing interest recently. However, the lack of efficient and cost-effective membranes has hampered the commercialization of MFCs. polyether sulfone (PES) hollow fiber was utilized as the separator in the cylindrical ml-scale active–air MFC to treat domestic wastewater. The conventional aeration unit replaced with the silicon membrane tube that was only passed the oxygen of air across wall membranes and provides appropriate dissolved oxygen in the cathode chamber. The increase in hydraulic retention time (HRT) (from 1.43 to 3.97 min) drastically improved the power and current densities of the MFC from 306.41±17.43 to 540.98 ±32.00 mW/m2, and from 1842.138±103.18 to 2191.83±160.06 mA/m2, respectively. The electricity generation performance gradually continued to grow by further extending the HRT from 3.97 to 10.19 min. The maximum power and current densities of 582.97±28.61 mW/m2 and 2404.15±140.61 mA/m2 are obtained at the HRT of 10.19 min. Similarly, the coulombic efficiency as well as the current and voltage generation of the MFC is enhanced by the increment of HRT. The maximum open circuit voltage and current of 768±14.10 mV, and 0.418±0.004 mA (with the external resistance of 986 Ω) are yielded at the HRT of 10.19 min. The rather low response time which was obtained for this hollow fiber-MFC (450 min) shows its potential applicability as a biosensor.