Microbial Electrochemical Systems (MESs) for Sustainable Wastewater Treatment

Microbial electrochemical systems (MESs) represent an emerging technology in bioelectrochemical wastewater treatment, leveraging the metabolic activity of electroactive microorganisms to generate electricity, hydrogen, and hydrogen peroxide (H2O2). These systems are classified into microbial fuel cells (MFCs), microbial electrolysis cells (MECs), and microbial peroxide-producing cells (MPPCs). MFCs generate electricity by oxidizing organic matter, while MECs apply an external voltage to drive hydrogen production. The latest advancement, MPPCs, focuses on microbial-driven electrochemical synthesis of hydrogen peroxide, which is a key reactant in AOPs. MESs offer a sustainable alternative to conventional electrochemical methods by reducing energy input and enabling on-site H2O2 production. However, challenges such as low power density, limited electron transfer efficiency, and biofilm formation must be addressed to enhance system scalability. Recent research has explored genetically engineered electroactive bacteria, optimized electrode materials, and co-culture strategies to improve performance. The integration of MESs with AOPs holds significant promise for degrading recalcitrant pollutants, treating industrial effluents, and reducing environmental impact. Future advancements should focus on reactor design, microbial optimization, and hybrid electrochemical-biological treatment systems to make MESs a viable solution for real-world wastewater treatment.