Peracetic Acid Activation by Modified Hematite for Water Purification: Performance, Degradation Pathways, and Mechanism.

Natural mineral-based advanced oxidation processes (AOPs) are now receiving increasing attention for the efficient degradation of pollutants. In this work, we used a common reducing agent (NaBH 4 ) to treat natural Hematite to obtain modified Hematite (Hematite-(R)) and applied it to activate peracetic acid (PAA) for efficient degradation of cefazolin (CFZ). Compared with Hematite, the Hematite-(R)/PAA system increased the degradation rate of CFZ by 21.7% within 80 min under neutral conditions. Scavenging experiments and electron paramagnetic resonance (EPR) technology were introduced to identify the principal roles of 1 O 2 , CH 3 C(O)OO • , and • OH for CFZ removal over the Hematite-(R)/PAA process. The outstanding capability of Hematite-(R) could be mainly due to the higher percentage of Fe(II) (52%) on the surface of catalysts. Furthermore, the possible degradation pathways of CFZ were explored. Moreover, the Hematite-(R)/PAA process showed a superior CFZ removal efficiency with a wide initial pH scope of 1.0-9.0. The degradation efficiency of CFZ showed a negligible effect in the presence of Cl - , SO 4 2- , and NO 3 - , while significant inhibition was recorded after the addition of H 2 PO 4 - and CO 3 2- . The inhibition of humic acid (HA) on CFZ degradation via the Hematite-(R)/PAA process showed an obvious concentration dependence. This work could provide strong support for the use of natural Hematite in water purification.