Comparative study of different hydro-dynamic flow in microbial fuel cell stacks

This work has investigated the scale-up potential of microbial fuel cells (MFCs) under stacking mode. Stacking was done in batch mode and continuous mode. Batch feeding mode stacks were operated in electrical series (S) and parallel (P) mode. Continuous feeding mode stacks were kept in electrically parallel mode with different hydro-dynamic patterns. The two continuous stacks were connected hydro-dynamically in series (i.e. Parallel Dependent; PD) and parallel (i.e. Parallel Independent; PID) configurations. The performance of the continuous stacks was evaluated on the basis of COD consumption rate, power generation and coulombic efficiency. PID obtained highest power (0.47 mW) which was approximately 3.6 times that of PD configuration (0.13 mW). The rate of COD consumption was also highest in PID stack (3091.75 mg·L−1·d−1). Coulombic efficiency of the PID stack was 14.26% which was approximately 292.8% of the PD stack. The results confirmed that the parallel electrical connection hybridized with the independent hydro-dynamic flow gives the best possible results when working with stacking of MFCs. © 2021 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd.