Effects of adsorption characteristics of carbocatalysts on persulfate-based advanced oxidation processes: Organic removal mechanisms and optimization strategies

Persulfate-based advanced oxidation processes (PS-AOPs) using carbocatalysts exhibit great potential for removing highly toxic organic pollutants from water. Nevertheless, the relationship between carbon adsorption and PS activation is ambiguous. This review discusses the adsorption characteristics of carbocatalysts to PS and organics, concluding that the cycle of adsorption and oxidation on carbocatalysts increases the reaction stoi-chiometric efficiency (RSE) and kinetic rate (kobs) of PS-AOPs. Furthermore, the influences of carbon adsorptive properties on PS activation pathways are analyzed. Generally, the free radical pathway occurs with weak carbon physisorption, while the non-radical pathway occurs with strong carbon chemisorption. The surface and struc-ture characteristics of carbocatalysts are investigated, which are responsible for the behaviors of adsorption and activation. Additionally, the optimization strategies of carbocatalysts are proposed to decrease the inhibition of co-existing organics and external substances in actual wastewater. This review provides a theoretical basis for developing carbon-activated PS-AOPs to treat organically polluted wastewater.