Reduction of Carbon Dioxide Emission by Using Microbial Fuel Cells during Wastewater Treatment

Abstract

To explore the feasibility of simultaneous carbon reduction and energy saving/recycling during wastewater decolorization, this study used naturally-occurring microbes (e.g., Aeromonas and Klebsiella sp.) for dye decolorization as well as energy and materials recycling. These microbes were tested for capabilities of bioelectricity generation in parallel with dye treatment for simultaneous energy recovery. The supplementation of electron-shuttling mediators (e.g., aminophenols) significantly increased the electron-transfer efficiency of electrochemically-active microorganisms. Moreover, the presence of decolorized intermediate(s) might repress intracellular accumulation of the biodegradable polyhydroxyalkanoates (PHAs), likely due to toxicity of aromatic amines. Microbial fuel cells (MFCs) appear to be feasible for use in the reduction of CO2 emitted (ca. 40–60 Faraday efficiency) during the generation of bioenergy (e.g., bioelectricity) and biomaterials (e.g., PHAs) in wastewater treatment, thus aiding the development of cradle-to-cradle sustainable designs.