An overview of microbial electrolysis cell configuration: Challenges and prospects on biohydrogen production

Microbial electrolysis cell (MEC) is a novel clean and green energy technology for biohydrogen production and simultaneously removes pollutants in terms of chemical oxygen demand, biological oxygen demand, total dissolved solids, colour, metal ions etc. from domestic, industrial and agricultural wastewater. MEC comprises of an anode and a cathode chamber separated by proton exchange membrane in which hydrogen is produced with the addition of a small electrical input (<1.2 V) due to the thermodynamic barrier. MEC is still in its inception stage and faces challenges in large-scale applications due to its design, electrodes, membrane cost, etc. In order to understand the applications of MEC, a review has been conducted to explore the various reactor configurations, including single and dual chamber, up-flow, packed bed, fluidized bed, and trickle bed reactors. In addition, basic principles, components required, MEC integrated with other bioelectrochemical system, challenges, pros and cons of reactor design have been discussed in this article. This review provides the advances and recent developments in research on MEC design, including mechanisms for real-time applications.

Automated summary

Microbial electrolysis cell (MEC) is a clean and green energy technology that produces biohydrogen and removes pollutants from wastewater. However, MEC is still facing challenges in terms of design, electrodes, and membrane cost for large-scale applications. This review summarizes the various reactor configurations of MEC, discusses its basic principles and required components, and explores the integration of MEC with other bioelectrochemical systems.