Degradation of 3,4-dichlorobenzotrifluoride by the Fenton-like process using zirconia-coated magnetite magnetic nanoparticles as an effective heterogeneous catalyst

Abstract

In this study, zirconia-coated magnetite magnetic nanoparticles (ZrO₂/Fe₃O₄ MNPs) were prepared, characterized, and used as an effective and reusable heterogeneous catalyst for 3,4-dichlorobenzotrifluoride (3,4-DCBTE) degradation. The catalytic potential of the Fe₃O₄/ZrO₂-H₂O₂ system for the removal of 3,4-DCBTE was tested in comparison with several other systems, and the effects of various operating parameters, including initial solution pH, catalyst addition, H₂O₂ concentrations, and reaction temperature, were also evaluated with respect to the degradation efficiency of 3,4-DCBTE. Results showed that the Fe₃O₄/ZrO₂ composite could effectively enhance the oxidation of 3,4-DCBTE by the Fenton-like process, and there might be a synergetic effect in the Fe₃O₄/ZrO₂ composite. When the mass ratio of Fe₃O₄ and ZrO₂ was 1:1, the Fe₃O₄/ZrO₂ exhibited the best catalytic activity, and the catalyst-driven Fenton process achieved high removal of 3,4-DCBTE (98.5%) and total organic carbon (TOC) (52.7%) at the operating conditions: pH 3.0, catalyst 2.0 g/L, H₂O₂ 30 mM, temperature 30 °C, and reaction time 1 h. Furthermore, five successive runs of the Fenton oxidation using the same Fe₃O₄/ZrO₂ composite resulted in the steady removal of 3,4-DCBTE, further confirming the high stability of the catalyst. In addition, the possible catalytic mechanism and degradation pathways of 3,4-DCBTE were also investigated.

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