Feasibility of a self-sustaining microbial fuel cell incorporating natural processes of bacteria and microalgae towards a circular bioeconomy

A microbial fuel cell (MFC) consisting of a bacterial anode chamber and a microalgal cathode chamber was operated under various conditions to assess its technical feasibility. Maximum achievable power density reached up to 7.13 mW m^–2. The traditional MFC process of conversion of carbon sources to bioelectricity in the anodic chamber was compared with a system circulating anodic effluent to the cathode chamber. The bacteria and microalgae simultaneously carried out the carbon recycling and recovery of energy and resources synergizing the performance of MFC. Results indicated a comparable chemical oxygen demand removal efficiencies at 50% of the retention time compared to the traditional system. The dissolved oxygen concentration varied between 11.95 and 7.44 mg L^–1 with Chlorella vulgaris under alternative light and dark cycles. Despite the variations in electricity output, the system showed its technical feasibility to harness energy for photosynthesis under natural sunlight conditions.