Enhanced degradation of refractory organics by bioelectrochemical systems: A review

Industrial production activities produce a large amount of chemical wastewater, which may pose a potential threat to the environment. Bioelectrochemical systems (BES) are a cutting-edge technology for the sustainable treatment of various types of wastewater while generating energy and value-added chemicals. BESs continuously provide electrons to improve the biological oxidation and reduction efficiency of refractory substances, being more efficient than in-situ bioremediation approaches. However, the BES performance is influenced by various factors, whose alteration can directly affect the processing effect and complicates operation. In addition, BES also needs to be improved in terms of scale and production capacity. This work reviews the influencing factors on BES performance, whose regulation can greatly improve the treatment effect. This work also summarizes the research situation and treatment effect of BES and BES coupling processes in the treatment of organic halogen compounds, petroleum hydrocarbons, and azo-dye wastewater based on some typical BES and BES coupling process examples, so as to highlight the contribution of BES to reducing operation costs and improving treatment efficiency. Although some advanced physical/chemical technologies have been widely reported and applied in the treatment of refractory organics, the high cost of these processes is an obstacle to their smooth application. Therefore, this work provides a new option for enhancing treatment of refractory organics and highlights prospects for future application and challenges of BES.