Roles and mechanisms of carbonaceous materials in advanced oxidation coupling processes for degradation organic pollutants in wastewater: a review

The widespread organic pollutants in wastewater are one of the global environmental problems. Advanced oxidation processes (AOPs) are widely used because of their characteristics of high efficiency and strong oxidation. However, AOPs may have some defects, such as incomplete mineralization of organic pollutants and the generation of toxic by-products during the degradation process, thus it is essential to seek efficient and green wastewater treatment technologies. Coupling different AOPs or other processes is beneficial for the mineralization of pollutants and reduces ecological risks to the environment. It is worth noting that carbonaceous materials (CMs) have received widespread attention and application in the degradation of organic pollutants in water by advanced oxidation coupling processes (C-AOPs) due to their excellent physicochemical properties in recent years. However, the behaviors and mechanisms of C-AOPs based on CMs on the degradation of organic pollutants are still unknown. Therefore, it is essential to comprehensively summarize the recent research progress. In this review, the applications of different CMs in C-AOPs were reviewed first. Secondly, the synergistic mechanisms of the C-AOPs based on different CMs were discussed. Then, toxic intermediates were explored and important toxicity assessment methods were proposed. Finally, the application potential of the C-AOPs in the future and the challenges were proposed. This review provides an important reference for the application and optimization of the C-AOPs in organic wastewater treatment in the future. Graphical Abstract