Advances in sulfate-reducing bacteria-driven bioelectrolysis: mechanisms and applications in microbial electrolysis cell technology

The discharge of sulfate-rich wastewater from chemical and pharmaceutical and food processing industries results in serious environmental problems that impact both the natural environment and human health. The conventional sulfate removal process using chemical precipitation consumes much energy and results in the production of additional pollutants that decrease its scalability and treatment performance. Microbial electrolysis cells (MECs) using sulfate-reducing bacteria (SRB) is a promising sustainable technology for treating wastewater and recovering resources because the metabolic process of SRB in MECs can convert sulfate to sulfide while the cells also produce bioenergy through electrochemical processes. This review focuses on the processes of sulfate reduction in MECs that have demonstrated potential for sulfate removal and hydrogen production and heavy metal elimination and organic pollutant degradation. This review also systematically discussed machine learning systems that optimize MECs performance and result prediction and efficiency enhancement. The SRB-MECs systems have two advantages by producing clean energy while treating wastewater that makes them suitable for application in industrial processes. The two main challenges for the implementation of these systems are the scalability of the system and its long-term operational reliability. This review highlights the need for more research to enhance system performance and microbial efficiency and accelerate the practical implementation of SRB-MECs technology as a sustainable and energy-efficient solution for treating industrial effluents.