Highly efficient removal and detoxification of phenolic compounds using persulfate activated by MnOx@OMC: Synergistic mechanism and kinetic analysis

• A MnO x @OMC composite was prepared for persulfate activation with high efficiency. • Phenol was effectively removed and detoxified by persulfate activation. • Synergistic effect between MnOx and OMC enhanced phenol removal performance. • A new kinetic model for phenol decay by persulfate was proposed. Persulfate-based advanced oxidation technology exhibits great potential for hazardous organic pollutant removal from wastewater. Acceleration of pollutant degradation needs to be elucidated, particularly for heterogeneous catalytic systems. In this study, manganese oxide ordered mesoporous carbon composites (MnO x @OMC) were prepared by nano-casting method and used for persulfate activation to degrade phenol. Kinetics analysis indicate that the rate of phenol degradation using MnO x @OMC composites was improved by 34.9 folds relative to that using a mixture of MnO x and OMC. The phenol toxicity towards Caenorhabditis elegans could be totally reduced within 8 min. The different roles of MnO x and OMC in persulfate activation were confirmed to validate their synergistic effect. MnO x provided major active sites for persulfate activation in accordance with the surface Mn 3+ /Mn 4+ cycle to induce SO 4 •− radicals. The OMC matrix provided the adsorption sites to enrich phenol molecules on the catalytic surface and promote the interfacial electron transfer process for persulfate activation. Moreover, a novel kinetic model with two distinct kinetic stages was established to verify the effects of phenol and persulfate on phenol removal.