Bioelectricity generation in annulus structure of single chamber membrane-less microbial fuel cell using wastewater from chocolate industry

Abstract

Microbial Fuel Cell (MFC) is an efficient system for generating low power where wastewater is substrate for the biocatalyst. In this work, Annular Single Chamber Microbial Fuel Cell (ASCMFC) with spiral anode was fabricated and tested. Carbon cloth and stainless steel 400 meshes were selected as cathode and anode electrodes, respectively. In order to enhance the conductivity of anode, the graphite coating was applied. A 40% platinum as catalyst was used on carbon based cathode in MFC. The carbon cloth was coated with 5% Nafion solution. In fact Nafion acts as Proton Exchange Membrane (PEM) in the fabricated MFC. For the first time, wastewater of Chocolate industry with COD 1400 mg/L was used as substrate in anode compartment. Also a mixture of anaerobic sludge from wastewater treatment plant (Qaem-Shahr, Iran) was introduced into MFC. Maximum voltage obtained in the ASCMFC system was 792 mV in an open-circuit mode. Also, Fabricated MFC operating at 30 ◦C, the maximum achieved power density using an external resistance of 500Ω was about 4.8 W/m3. The upshots from single chamber MFC were compared to dual chamber MFC. The findings demonstrate that, due to the generated high power density and voltage by the cell, the ASCMFC has a great potential for COD removal and wastewater treatment.