A Short Review on Recent Advanced Oxidation Technologies for Microplastics Degradation

Microplastics comprise plastic particles that are less than 5 mm in size. Owing to a significant increase in plastic production, micro plastics have become ubiquitous pollutants worldwide. Several studies have reported that microplastics are harmful to living organisms because they can adsorb contaminants from the environment due to their unique physicochemical properties. The adsorbed contaminants on microplastics can be released and accumulated in living organisms, thereby adversely affecting the health of humans and animals. Since existing water treatment technologies as stand-alone processes cannot achieve complete removal of microplastics, reliable methods must be developed. Advanced oxidation processes (AOPs) are a promising approach for the chemical treatment of contaminants such as microplastics. These processes utilize highly reactive oxygen species (e.g., hydroxyl radicals, sulfate radicals, superoxide anions, and singlet oxygen) to decompose microplastics completely. However, at this stage, AOPs can partially degrade and/or alter surface chemistry of microplastics. Therefore, extensive effort must be made to further study AOPs for complete decomposition of microplastics.