Scaling up a novel denitrifying microbial fuel cell with an oxic-anoxic two stage biocathode

A scaled up microbial fuel cell (MFC) of a 50 L volume was set up with an oxic-anoxic two-stage biocathode and activated semicoke packed electrodes to achieve simultaneous power generation and nitrogen and organic matter removals. An average maximum power density of 43.1 W·m^-3 was obtained in batch operating mode. By adjusting the two external resistances, the denitrification in the A-MFC and power production in the O-MFC could be enhanced. In continuous mode, when the hydraulic retention times were set at 6 h, 8 h and 12 h, the removal efficiencies of COD, NH4+-N and total nitrogen (TN) were higher than 95%, 97%, and 84%, respectively. Meanwhile the removal loads for COD, NH4+-N and TN were10, 0.37 and 0.4 kg·(m³·d)^-1, respectively.