Bioelectricity Generation From Synthetic Wastewater Treatment in a Membrane-Less Microbial Fuel Cell Using Methylene Blue and/or Neutral Red as Mediators

Abstract

Microbial fuel cells (MFCs) represent a new method for treating wastewaters and simultaneously producing electricity (renewable energy (bioelectricity)) as innovative technologies. Feasibility of using synthetic wastewater as a substrate for electricity generation using anaerobic sludge as a source of microorganisms was investigated after a short acclimatization period of less than 10 days. among two different kind substrate (methanol and acetic acid) Significant reduction in COD of synthetic wastewater by 63% and 75% was observed at initial COD=2743 mg/l and 2560 mg/l respectively in Methanol and Acetic Acid indicated effective wastewater treatment in batch experiments. The present article deals with the studies of a two chambered salt bridge (membrane-less) MFC anode chamber [(with mediator; plain graphite electrode; acidified by ortho-posphoric acid (pH≈6)]; cathode chamber (50mM potassium ferricyanide [K3Fe(CN)6] in phosphate buffer; pH ≈7.5; plain graphite electrode) in the presence of mediators. The effect of Methylene Blue (MB) and Neutral Red (NR) as electron mediators and microelements inoculated to anolyte chamber on the power generation in MFCs are reported. The best performance was obtained in the case of Acetic Acid. Using methylene blue (MB) (0.2mM) as the electron mediator, the maximum power density and current density of 61.718 mW/m2 and 92.530 mA/m2 were obtained respectively with CE of 3.94%, which are found to be very promising. The maximum power density and current density of 58.820 mW/m2 and 89.940 mA/m2 were obtained respectively with CE of 8.05%. In the most cases, results show that MB has more effective role than NR. Efforts are being made to improve the performance and reduce the construction and operating costs of MFCs.