Microplastics in Water: A Review of Characterization and Removal Methods

Abstract

Microplastics (MPs), as an emerging persistent pollutant, exist and accumulate in the environment, which has garnered them considerable global attention. While the origin, dispersion, distribution, and impact of MPs have been extensively documented, the characterization and removal strategies for MPs present ongoing challenges. In this literature review, we introduce in detail the advantages and disadvantages of seven characterization methods, from macroscopic to microscopic, from visual observation to microscopic characterization, and discuss their scope of application. In addition, 12 treatment schemes were summarized from the three treatment directions of physics, chemistry, and biology, including filtration, adsorption, extraction, magnetic separation, oil film separation, Fenton oxidation, electrochemical oxidation, persulfate advanced oxidation, photocatalytic oxidation, coagulation, electrocoagulation, foam flotation, anaerobic–anoxic–aerobic activated sludge, enzymatic degradation, bacterial degradation, and fungal degradation. Additionally, we present a critical assessment of the advantages and drawbacks associated with these removal strategies. Building upon the findings of our research team, we propose a novel approach to degrade MPs, which combines three-dimensional electrocatalytic oxidation technology with persulfate advanced oxidation technology. This advanced oxidation technology achieves 100% degradation of antibiotics in water, can degrade large molecules into environmentally harmless small molecules, and should also be a very good strategy for the degradation of MPs. Compared with two-dimensional electrocatalytic technology, the degradation efficiency is higher and the degradation cost is lower This review intends to propel further advancements for addressing the issue of MP pollution.