Bioelectrochemical systems – A potentially effective technology for mitigating microplastic contamination in wastewater

Microplastics are refractory pollutants extensively present in wastewater treatment, which not only directly impact the metabolic activity of microorganisms, but also can directly or indirectly affect the environment and human health by adsorbing and releasing other pollutants in wastewater. Bioelectrochemical systems (BES), as a wastewater treatment technology of microbial metabolism coupled with electrochemical reactions, are progressively being employed for the treatment of refractory pollutants due to their superior oxidative and reductive reaction properties. Therefore, the main focus of this review is to analyze the adverse effects of the presence of microplastics on anaerobic wastewater treatment and to explore the possibility of using BES to alleviate this pollution effect. Due to the lack of relevant literature, this review can only demonstrate the potential ways BES to mitigate microplastic toxicity in wastewater by analyzing the detrimental effects of microplastics generated and the promoting effect of BES during the anaerobic fermentation of the wastewater. This review illustrates the possible roles of BES in microplastic-contaminated wastewater including BES accelerating the aging and decomposition process of microplastics in wastewater, BES enhancing the metabolic activity of microplastic-degrading microorganisms, BES strengthening the resistance of microorganisms to microplastics and the contaminants they release or adsorb and BES attenuating the compounding effect of other pollutants. This review is the first to explore the possibility of using bioelectrochemistry technology to mitigate microplastic contamination in wastewater. These analyses provide new insights into mitigating the adverse effects of microplastics in wastewater treatment processes.