Enhanced performance of an air–cathode microbial fuel cell with oxygen supply from an externally connected algal bioreactor

[Display omitted] •MFC power generation was enhanced with high oxygen levels from algae bioreactor.•Cathodic reduction current was increased with oxygen from algae bioreactor.•MFC performance was well maintained with algae oxygen supply in long term operation.•Algae bioreactor aeration kept membrane well hydrated without salt depositions. An algae bioreactor (ABR) was externally connected to air–cathode microbial fuel cells (MFCs) to increase power generation by supplying a high amount of oxygen to cathode electrode. The MFC with oxygen fed from ABR produced maximum cell voltage and cathode potential at a fixed loading of 459mV and 10mV, respectively. During polarization analysis, the MFC displayed a maximum power density of 0.63W/m2 (at 2.06A/m2) using 39.2% O2 from ABR, which was approximately 30% higher compared with use of atmospheric air (0.44W/m2, 20.8% O2,). The cyclic voltammogram analysis exhibited a higher reduction current of −137mA with 46.5% O2 compared to atmospheric air (−115mA). Oxygen supply by algae bioreactor to air–cathode MFC could also maintain better MFC performance in long term operation by minimizing cathode potential drop over time.