Simultaneous carbon removal, denitrification and power generation in a membrane-less microbial fuel cell

A membrane-less microbial fuel cell (ML-MFC) was developed to investigate the simultaneous carbon removal and denitrification. The removal rates of 0.64 kg COD m−3 of liquid cathode volume (LCV) d−1 and 0.186 g NO 3 - – N m - 3 of LCV d−1 were achieved, which resulted in the maximal COD and nitrate removal rates of 100% and 36.7%, respectively. The ML-MFC also achieved a maximal power output of 0.0712 W m−3 of LCV and 0.844 A m−3 of LCV in approximately 24 h. The maximal coulombic efficiency of anode (CEAn) and cathode (CECa) was 5.1% and 475%, respectively. The anodic gas phase was consisted of 77.2 ± 4.0% CH4, 3.9 ± 0.5% CO2, and 3.9 ± 1.5% N2, which indicated that the low anode coulombic efficiency was due to anodic methane production. The results of this study demonstrated the potential application of ML-MFC in simultaneous carbon and nitrogen removal and energy (electricity) production.