Degradation of Microplastics in the Aquatic Environment by Advanced Oxidation Process

Advanced oxidation processes (AOPs) were found to be a potential solution for degrading microplastics (MPs) from the environment as these processes are green, environmentally friendly, and utilize strong oxidants that are proven to be highly effective against several recalcitrant pollutants. In this chapter, the principles of several AOPs, such as electrooxidation (EO), photocatalytic oxidation (PCO), UV/ H2O2, ozone-based processes, and Fenton-based processes, for the removal of MPs have been discussed. EO has been found to be effective in the removal of MPs, with careful consideration required when selecting an appropriate anode and supporting electrolyte. The utilization of a boron-doped diamond (BDD) anode and sodium sulfate as supporting electrolyte has shown superior results in the removal of MPs. The MP removal efficiency in the PCO process mostly relies on the type of catalyst used. In UV/H2O2 process, it is crucial to ensure the proper amount of UV irradiation and the optimum amount of H2O2 to achieve the highest removal efficiency. Thermal and photo Fenton have shown promising results in removing MPs. Additionally, this chapter highlights the need for further study of the degradation of MPs, the potential production of toxic compounds during the process, feasibility and scalability of AOPs.