Granular activated carbon in capacitive microbial fuel cells

Wastewater represents a very suitable source of energy, as it contains organic compounds that need to be removed and can be converted into valuable products (e.g. methane, chemicals). In this context, Microbial Fuel Cell (MFC) is a sustainable and efficient technology to recover electricity from organics in wastewater, thus making profit from a treatment process. Microorganisms oxidize the organics (e.g. acetate) in the wastewater and produce electrons, which are then transferred from the anode to the cathode producing thereby current. In this study, capacitive MFCs are studied as an alternative to classical MFCs. The main difference relies on the use of capacitive materials as electrodes which provide with a large (porous) surface area for the growth of biofilms as well as the storage of electrons in form of electrical double-layer (EDL). Granular activated carbon represents a suitable three-dimensional capacitive electrode material for MFCs that can be implemented under many reactor configurations (e.g. fixed or fluidized beds).