Dual-Chambered Membrane Microbial Fuel Cell: Limitation On Potential Difference G. S. Jadhav, Y. D. Jagtap and M. M. Ghangrekar 1, 2 Rajgad Dnyanpeeth’s Shri Chhtrapati Shivajiraje College of Engineering, Pune, India. 3 Department of Civil Engineering, Indian Institute of Technology, Kharagpur 721302, West Bengal, India Abstract Performance of two microbial fuel cells (MFCs) was investigated under batch mode of operation using aerated distilled water as cathodic electrolyte. Stainless steel (SS) mesh anode was used in both the MFCs with surface area of 100 and 170 cm 2 in MFC-1 and MFC-2, respectively. Stainless steel (SS) mesh cathode with surface area of 33.9 cm 2 was used in MFC-1, where as graphite rods cathode with surface area of 150 cm 2 was used in MFC-2.Under batch mode of operation, these MFCs gave chemical oxygen demand removal efficiency in the range of 85-87 % and about 87-92 %, respectively. Anodic electrolyte pH was decreased for both MFCs, where as cathodic electrolyte pH was increased in MFCs. Carbonate alkalinity, bicarbonate alkalinity, hardness and TDS (total dissolved solids) of cathodic electrolyte were increased in both MFCs. 1. Introduction Microbial fuel cell (MFC) provides new opportunity for the sustainable production of energy, in the form of direct electricity from biodegradable compounds present in the wastewater. MFC is a device that converts chemical energy to electrical energy with the aid of the catalytic reaction of microorganisms [1]. The MFC system often consists of two compartments normally separated by a PEM. In the anaerobic compartment microorganisms oxidize substrate [2]. The generated protons migrate from the anaerobic compartment to the aerobic compartment through the PEM. The produced electrons are transferred to the anode and then pass through an external electric circuit to the cathode, where they reduce oxygen to form H 2 O. [3-4]. Performance of a MFC is affected by the substrate conversion rate, over-potentials at the anode and at the cathode, the PEM performance, and internal resistance of the cell [5]. The optimization of MFCs requires extensive exploration of the operating parameters that affect the power output. A sound body of literature supports the exploration of different parameters such as surface area of electrode, different materials as electrodes, use of special aerobic culture of Shewanella oneidensis DSP10 as the active electrochemical species in the anode chamber [6], sedimentary bacterium [7], Geobacter sulfurreducens [8], sedimentary bacterium [7]; cathode performance with different electron acceptor such as a permanganate, oxygen [9-10]; and Hexacyanoferrate [10]; spatial arrangement of effluent with respect to PEM [9]; electrode distance [11]; cathode surface area and cathode mediator [12]; and operating parameters such as pH, temperature[13] etc. This study was aimed to investigate the effect on cathodic electrolyte of MFC and to investigate factors affecting reduction of potential difference, under batch mode of operation using dual chambered membrane MFC. 2. Materials and methods 2.1. Microbial fuel cell Two dual-chambered MFCs were constructed from acrylic sheet, with difference of anode surface area, anode orientation, cathode material and cathode area. MFC-1 was provided with L-shaped stainless steel (SS) mesh anode electrode, having surface area of 100 cm 2 . Stainless steel (SS) wire mesh square cage of side 7×7 cm and length of 7 cm as anode electrode, offering total surface area of 170 cm 2 , was used in MFC-2. Stainless steel was used as a cheaper replacement to the graphite electrode and as an easily available material in mesh form to offer more surface area per unit volume [9]. Total working volume of each anode and cathode chamber was 1,330 ml for MFC-1 and 1,310 ml for MFC-2. Proton exchange membrane of 0.007 inch thickness (Nafion ® 117, Aldrich) was used to separate both chambers. Membrane surface area of 25.0 and 24.01 cm 2 was used in MFC-1 and MFC-2, 1638 International Journal of Engineering Research & Technology (IJERT) Vol. 2 Issue 4, April - 2013 ISSN: 2278-0181 www.ijert.org