Abstract: In order to avoid catalyst loss and enhance treatment efficiency of non-degradable organic wastewater, MgO-Fe₂O₃/acid-modified zeolite catalyst (MFZ) was prepared by impregnation method. The structure and composition of the catalyst were analyzed by scanning electron microscope-energy dispersive
spectrometer (SEM-EDS), X-ray diffractometer (XRD), X-ray photoelectron spectrometer (XPS), automatic specific surface area and micropore analyzer and Fourier transform infrared spectrometer (FTIR). The effects of ozone concentration, initial solution pH and catalyst dosage on the removal efficiency and reaction rate of sulfamethoxazole (SMX) were studied. A reaction kinetics model was established to explore the degradation pathways and reaction mechanisms of catalytic ozonation of SMX wastewater by MFZ, and a bio-toxicity on the leachate of MFZ catalyst was studied. The results showed that MFZ retained the high mesoporous framework structure of natural zeolite, and the specific surface area, pore volume, and pore size were 12.670 m²/g, 0.044 cm³/g, and 4.012 nm, respectively. MgO-Fe₂O₃ was uniformly loaded on the zeolite surface, and the abundant oxygen vacancies and surface hydroxyl groups could promote the decomposition of O₃ to produce ·OH. Catalytic ozonation degradation of SMX followed a second-order reaction kinetics model using MFZ. The initial pH of the solution had the greatest impact on the removal rate and reaction rate of SMX, with the highest removal rate of 72% and the highest reaction rate of 0.1309 min^-1. The degradation process of SMX in the MFZ/O₃ system consisted of two parts: direct oxidation by O₃ and indirect oxidation by ·OH, and ·OH played a major role. The decomposition of SMX was mainly achieved through amino oxidation and hydroxylation, as well as the breaking of sulfur nitrogen and nitrogen oxygen bonds on the heterocyclic ring, resulting in mineralization into small molecules such as carbon dioxide and water. The average root length and germination index of Chinese cabbage cultured in the leachate of MFZ increased by 10.34% and 17% compared to water, which could promote the germination and growth of Chinese cabbage. The leachate of MFZ catalyst could significantly promote the germination and growth of pakchoi.