A systematic review of electrocoagulation technology applied for microplastics removal in aquatic environment

Microplastics (MPs) are relatively stable and not easy to degrade, which poses a serious threat to the environment and biological health. MPs pollution is also listed as a global environmental problem alongside global climate change, ozone layer depletion, etc. Studying the environmental behavior and pollution status of MPs in water environments is of great significance for a comprehensive assessment of MPs in water. Furthermore, efforts to find an effective technology for aqueous removal of MPs requires urgent attention. Electrocoagulation (EC) technology is a promising water treatment technology for MPs removal with the advantages of high efficiency, simple operation and low sludge production. Unfortunately, the lack of a comprehensive summary on the mechanism of EC to remove MPs, the effects of experimental parameters and even how to strengthen this technology, limits its implementation on the industrial scale. Therefore, in this paper, we present reviews on the recent research progress of EC to remove MPs. The fundamentals of the EC process, the effect of its operating conditions (electrode materials, current density, supporting electrolyte, and pH) and the removal mechanism of MPs are highlighted. Moreover, the enhanced process of removing MPs from EC wastewater is also summarized, including reactor design, electrode design and combined processes. This review not only helps researchers and policy makers to gain deeper understanding of the specific processes and mechanism of EC to remove MPs in water, but also provides ideas and references for future research on enhanced removal of MPs in the aquatic environment.