Design and Evaluation of the Influence of Mutual Induction on Microbial Electrolysis Cell Performance and Biogas Production

Microbial electrolysis cells (MECs) present a pathway for energy recovery in wastewater treatment by converting organic substrates into methane or hydrogen. Traditional MEC designs typically rely on physical electrode contacts and expensive materials, which restrict their scalability. This study introduces the first induction-based MEC that uses mutual inductance between an external copper wrap and an internal coil to generate a fluctuating electrical potential, removing the need for expensive electrodes. The induction-stimulated reactor showed faster total organic carbon removal and a higher CH4/CO2 ratio compared to a conventional anaerobic digester, indicating improved carbon-to-methane conversion, although total gas yield remained similar. Microbial community analyses revealed that methanogenic groups were more enriched on the induction coil surface, while exoelectrogenic taxa were unexpectedly more abundant on the Control coil. Overall, induction enhanced methane purity, carbon uptake, and microbial selectivity. This work presents the first implementation of induction as a driving force for MECs and provides a foundation for future experimental designs aimed at optimizing induction-driven systems for enhanced biogas production and purity.