Economic Assessment of Nanomaterials in Bio-Electrical Water Treatment

Abstract

Materials testing in bio-electrical systems (BES) currently experiences a Cambrian explosion. Combinations of materials on electrodes, membranes, and in the electrolyte are virtually infinite. The use of nanomaterials in BES has great prospects as many of the “nano-benefits”, such as large surface area, material savings, and scalability, are indispensable for successful commercialization of BES. Since the first stage of commercial BES development has been wastewater treatment, we focus on this application. In our survey of most recent literature we focus on the economic benefits. We discovered that there is no common benchmark for performance, as it is usual in photovoltaics or for batteries. To normalize our findings, we use dollar per peak power capacity as ($Wp−1) as it is standard in photovoltaics. The median cost for air cathodes of microbial fuel cells (MFCs) is $4700 Wp−1 ($2800 m−2). Platinum on carbon (Pt/C) and carbon nanofibers are the best performing materials with $500 Wp−1 (Pt/C $2800 m−2; nanofibers $2000 m−2). We also briefly explain the different kinds if nanomaterials in BES: carbon-based, metal and metal composites, as well as mineral materials. These types of materials were used for different components of BES: anodes, cathodes, membranes, and electrolytes. We found that carbon-based nanomaterials often deliver performance comparable to Pt/C. While still far away from being profitable, with these new materials, MFCs are moving closer to become an economic reality.