Optimizing Electrode Design for Microbial Fuel Cells Used for Wastewater Treatment

Microbial fuel cells (MFC) utilize bacteria to generate an electrical current that can be used in the decomposition of sludge and human urine. In a MFC there is an anode (for oxidation of organic compounds), cathode (reduction of oxygen or carbon dioxide), and a proton exchange membrane (PEM, allows protons to migrate); reduction-oxidation reactions between the anode and cathode produce a measurable current. Bacteria that are found in sludge can be used to produce electrons in a voltaic cell, but optimizing conditions for harnessing the energy is crucial to making a MFC efficient. Research has shown that the ratios of surface area for the cathode and anode, as well as, the ratio of surface areas of the cathode and the PEM affect the power density. The objective of this research project is to optimize the electrodes, both size and material, for a MFC. In order to optimize the electrodes, flow tests will be conducted to determine the best flow rate and electrode pattern based on the flow patterns observed. This experiment will ensure that nutrients and species involved in red-ox reactions are distributed evenly across the electrode, making the cell more efficient and maximizing power density