Principal, Mechanism, and Basic Thermodynamics of Microbial Electrolysis Cell

Microbial electrolysis cell is a technology that was initially designed to produce hydrogen. This technology requires a biologically assisted anodic chamber, while hydrogen is produced in the cathodic chamber under an applied external voltage. In the microbial colonized anodic chamber, in which electroactive bacteria (EAB) promote electron transfer, a wide variety of organic compounds can be oxidized, which makes this technology promising in wastewater treatment with the advantage of producing hydrogen at the same time. However, scaling up of this technology has not been fully successful yet and production of hydrogen is still low in comparison with water electrolysis. In this chapter, the basic thermodynamics and fundamentals of MEC are presented first initiating with the thermodynamics of an abiotic cell which is the basis of the water electrolysis and a brief description of the mechanism occurring in these biological assisted systems.