The operation of photosynthetic microbial fuel cells powered by Anabaena variabilis

An air-cathode dual-chamber photosynthetic microbial fuel cell (PMFC) is developed for generating electrical energy through harnessing solar energy by Anabaena variabilis. The PMFC can be operated continuously for 25 days with stable power output without adding any mediator. The aim of this work is to study the PMFC performance and the effect of phosphate buffer and NaCl solution as cathode electrolyte on electricity production process. The results show that the highest power density (47.6 mW/m2) was achieved by a PMFC using NaCl solution as the cathode electrolyte. This is attributed to a larger decrease in internal resistance induced by NaCl solution as compared with the phosphate buffer. NaCl solution leads to an increase in power production by 186.7% than phosphate buffer at the same concentration. Bacteria infection was also found in the anode chamber which is likely the cause of higher power output than PMFC using pure culture.