The synergistic interactions of reaction parameters in heterogeneous peroxymonosulfate oxidation: Reaction kinetic and catalytic mechanism

The reaction parameters including catalyst dosage, oxidant amount, initial contaminant concentration and pH etc. play the crucial roles in the heterogeneous persulfate oxidation processes, while the synergistic interactions among these reaction parameters are still obscure. We herein took an efficient heterogeneous persulfate oxidation system "bimetallic MnxCo3_ xO4 solid solution (MnCo) activated peroxymonosulfate (PMS)" for carbamazepine (CBZ) removal from water. MnCo/PMS system exhibited outstanding performance that CBZ was completely removed within 10 min. The CBZ degradation performance was ascribed to the radical oxidation of SO4.- and O2.-, the nonradical oxidation of 1O2, the redox cycles between Mn and Co species and synergistic interactions among MnCo, PMS and CBZ. By monotonously or synchronously adjusting the MnCo dosage, PMS amount and initial CBZ concentration, the inherent connections of different reaction parameters were established. Strong and different synergistic interactions between MnCo and PMS, and among MnCo, PMS and CBZ, were existed due to the formation of three different reaction modes when reaction parameters met certain conditions. The features of the modes were "two-stage, the following auto-deceleration", "one-stage, constant velocity" and "two-stage, the following auto-acceleration". This discovery may provide new insights into the synergistic interactions of reaction parameters in advanced oxidation processes for wastewater treatment.