Enhanced microbial fuel cell for electricity generation from wastewater

Abstract

The Microbial Fuel Cells (MFCs) are typically designed as a two-chamber system with the nutrient medium in the anode chamber separated from the cathode chamber by a polymeric Proton Exchange Membrane (PEM). One of the drawbacks of MFC operation is its low power output, and these are due to some of the limitations. This project investigates on the various modifications to the coatings and chemical enhancement on the surface of the cathode. The cathode was made up of pre-treated (PTFE) carbon cloth material. It consists of a Micro- porous layer (MPL) and a Platinum catalyst layer bonded to the carbon cloth with the use of PTFE and Nafion as binders respectively. The primary concern in the modified set up was to alter the position of the cathode structures such that these two layers were placed together on the same side facing the substrate medium. Results from calculations showed that cell potential improved by approximate 15%, power densities improving by 30%, COD removal efficiency improving by 30% and cathode vs. SCE potential improved by approximate 20%. The MFC performance tests demonstrated that the ‘modified’ cathode structure has a great potential in future development due to its enhanced mass transfer properties and oxygen reduction kinetics. Scanning Electron Microscope (SEM) images were also visualized to observe the surface structures and morphology. Close observations from the SEM showed that the MPL and Pt. Catalyst coating were not ideally done. It was noted that the level of difficulty to achieve a good and evenly spread coating on the electrode surface was difficult to achieve.