Optimizing energy productivity of microbial electrochemical cells

Microbial electrochemical cells, such as microbial fuel cells (MFCs) and microbial electrolysis cells (MECs) are bioreactors that produce energy from organic matter, e.g. wastewater. The goal of this work is to optimize their product generation, either electricity or hydrogen, by selecting optimum operating current, with the influent flow (organic load) being adjusted to guarantee a given treatment capacity. Analysis of a multi-population model of a microbial electrochemical cell reveals that the ratio between different microbial populations in the anodic biofilm is determined by the current. Furthermore, the optimal operating current varies considerably with the internal resistance. (C) 2012 Elsevier Ltd. All rights reserved.