Recent advances and trends in microbial fuel cells

With the rapid growth of the worldʹs population and economy, demands for energy are increasing significantly. At the same time, industrial effluent and domestic wastewater are also constantly increasing. The simultaneous production of energy and the degradation of contaminants in wastewater can provide economic and environmental benefits from microbial fuel cells (MFCs ). Production of electricity from renewable organic matter via MFCs has been explored since thel960s. MFC is an electrochemical device that utilizes microorganisms as biocatalysts to decompose organic or inorganic matter and treat organic waste materials simultaneously [2,3]. A typical MFC consists of two compartments, anodic and cathodic chambers being separated by a proton/cation exchange membrane or sometimes salt bridge. Generally, the microorganisms in the anode chamber degrade organic materials to proton and electron, anaerobically. The produced electrons at the surface of the anode electrode travel to the cathode electrode through an external circuit. Protons migrate to the cathodic chamber through proton exchange membrane separator. Electrons combine with protons and oxygen at the surface of cathode electrode to produce water in the electrochemical reduction reaction. The MFC as a novel technology has different applications, which can be classified into four major categories including: (1) electricity generation, (2) biological hydrogen production, (3) wastewater treatment, and (4) biosensors [5,6]. Therefore, MFCs are rapidly evolving technologies that will fascinate scientists and engineers who are challenged with waste technologies and energy production in the coming decades.