Comparison of phenacetin degradation in aqueous solutions by catalytic ozonation with CuFe2O4 and its precursor: Surface properties, intermediates and reaction mechanisms

• The precursor of CuFe2O4 showed a better performance than CuFe2O4.
• The precursor of CuFe2O4 enhanced ozone mass transfer and H2O2 formation.
• Intermediates and pathway of phenacetin in different processes were identified.

In this study, a new magnetic catalyst for enhancing the ozonation process, named as CFOH, a precursor of CuFe2O4 (CFO) was used to enhance the ozonation. The comparison of the surface properties, performance, and reaction mechanisms of CFO and CFOH in catalytic ozonation was investigated. The CFOH showed higher surface area, pore volume, and stronger acidic sites than those of CFO. Importantly, both CFOH and CFO exhibited magnetization, which can be used to separate the catalysts from the bulk solution for reuse. In addition, faster degradation and mineralization of phenacetin (PNT) in catalytic ozonation by CFOH were observed. The generation/decay of intermediates and H2O2 were identified in the studied processes. The yield and decomposition rate of H2O2 in the reaction determined the concentration of OH, which was found to be the key for the better catalytic activity of CFOH. Furthermore, the fates of benzene- and open-ring intermediates in the processes were also investigated. The surface reactions, including surface adsorption and catalytic reaction were observed for the mineralization of intermediates generated from PNT oxidation. These surface reactions became more significant when using CFOH as the catalyst, which justifies the better mineralization ability of CFOH.

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