Microbial Fuel Cell

Introduction Microbial fuel cells (MFCs) are bioreactors that convert chemical energy stored in the bonds of organic matters into electricity through biocatalysis of microorganisms (Potter, 1911; Cohen, 1931; Davis and Yarbrough, 1962; Moon et al., 2006). The schematic of a typical MFC is shown in Fig. 1. In the sketch below, the anodic and cathodic chamber are separated by a proton exchange membrane (PEM) (Wilkinson, 2000; Gil et al., 2003) that allows transport protons while blocking oxygen and other compounds. Microbes in the anodic chamber degrade organic matters and produce electrons, protons and carbon dioxide. Electrons and protons produced by microbes are then transported to the cathodic chamber via external circuit and a proton exchange membrane (PEM), respectively. In the cathodic chamber, protons and electrons react with oxygen to form water. Because the terminal electron acceptor (i.e., oxygen) is kept away from the anodic chamber, electrons are allowed to pass through the external load to generate electricity (Du et al., 2007).