Activation of peroxymonosulfate by Al2O3-based CoFe2O4 for the degradation of sulfachloropyridazine sodium: Kinetics and mechanism.

Al 2 O 3 -based CoFe 2 O 4 (CoFe 2 O 4 /Al 2 O 3 ) as a catalyst was prepared to activate peroxymonosulfate (PMS) for degradation of sulfachloropyridazine (SCP). In general, the catalytic performance of CoFe 2 O 4 /Al 2 O 3 in activation PMS was demonstrated more effective than CoFe 2 O 4 . Several influence factors were inspected, including scavengers, PMS concentration, pH, anions, nature organic matter (NOM) and temperature. The oxidation of SCP fitted a pseudo-first-order kinetics model and was efficient with the pH from 5.00 to 8.00. The influence of scavengers demonstrated that SO 4 - · played a more significant role than HO · in the oxidation process. The removal was strongly inhibited by adding NOM or HCO 3 - , and almost unaffected by adding NO 3 - , while chloride could enhance the degradation in the system. The increasing temperature greatly promoted the degradation of SCP. After four recycles, CoFe 2 O 4 /Al 2 O 3 still showed preferable catalytic performance with 97.6% removal rate of SCP. Furthermore, the degradation mechanism was explored based on the XPS results. In the composit of CoFe 2 O 4 /Al 2 O 3 , Al 2 O 3 had no additional catalytic performance but just as a matrix base. [ABSTRACT FROM AUTHOR]