Activation of peroxymonosulfate by Co2P via interfacial radical pathway for the degradation and mineralization of carbamazepine

Peroxymonosulfate (PMS)-based advanced oxidation processes (AOPs) have raised wide attention due to the efficient degradation of pollutants. However, the low efficiency in PMS activation is still a challenge for practical application. Herein, an economic Co2P catalyst with surface-active center was constructed for PMS activation to induce fast degradation of carbamazepine (CBZ). Particularly, the removal ratio of CBZ in the Co2P/PMS system could achieve at 98% in 10 min, accompanied with the removal ratio of total organic carbon (TOC) reached 60% in 60 min. Characterizations indicated that interfacial transformation of Coδ+ to Co2+ promoted electron-rich Co center formation, which supplied electrons for PMS to produce SO4•–and •OH that were responsible for the efficient degradation of CBZ. Furthermore, potential interferences from the real water matrix, dosage of the catalyst and PMS, and variation of initial pH were carefully studied for practical applications. Besides, three possible degradation pathways of CBZ were proposed and the toxicity of the products was predicted. However, the generation of more toxic intermediates was found in the system for the radical (SO4•–and •OH) oxidation is a non-selective oxidation process. Particularly, we expect that this work can provide new insights into the regulation of reaction mechanisms, degradation routes and safe transformation in PMS-AOPs for wastewater treatment.