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In this study, a highly efficient peroxymonosulfate (PMS) activator, ZnO/ZnMn2O4, was synthesized using a simple one‐step hydrothermal method. The resulting bimetallic oxide catalyst demonstrated a homogenous and high‐purity composition, showcasing synergistic catalytic activity in activating PMS for degrading 2, 4‐dichlorophenol (2, 4‐DCP) in aqueous solution. This catalytic performance surpassed that of individual ZnO, Mn2O3, and ZnMn2O4 metal materials. Under the optimized conditions, the removal efficiency of 2, 4‐DCP reached approximately 86% within 60 min, and the catalytic ability remained almost constant even after four cycles of recycling. The developed degradation system proved effective in degrading other azo‐dye pollutants. Certain inorganic anions such as HPO4−, HCO3−, and NO3− significantly inhibited the degradation of 2, 4‐DCP, while Cl− and SO42− did not exhibit such interference. Results from electrochemical experiments indicated that the electron transfer ability of ZnO/ZnMn2O4 surpassed that of individual metals, and electron transfer occurred between ZnO/ZnMn2O4 and the oxidant. The primary active radicals responsible for degrading 2, 4‐DCP were identified as SO4•−, OH• and O2•−, generated through the oxidation and reduction of PMS catalyzed by Zn (II) and Mn (III). Furthermore, X‐ray photoelectron spectroscopy (XPS) analysis of the fresh and used catalysts revealed that the exceptional electron transfer ability of ZnO facilitated the valence transfer of Mn (III) and the transfer of electrons to the catalyst's oxygen surface, thus enhancing the catalytic efficiency. The analysis of radicals and intermediates indicates that the two main pathways for degrading 2, 4‐DCP involve hydroxylation and radical attack on its aromatic ring. Practitioner Points: A bimetallic ZnO/ZnMn2O4 catalyst was synthesized and characterized.ZnO/ZnMn2O4 can synergistically activate PMS to degrade 2, 4‐DCP compared with single metal oxide.Three primary active radicals, O2•−, •OH, and SO4•−, were generated to promote the degradation.ZnO promoted electron transfer among the three species of Mn to facilitate oxidizing pollutants.Hydroxylation and radical attack on the aromatic ring of 2, 4‐DCP are the two degradation pathways. [ABSTRACT FROM AUTHOR]

Decolorization and degradation of C. I. Disperse Blue 56 (DB 56) in aqueous dispersion by the methods of UV, NaCIO, and UV/NaCIO, respectively, has been investigated in the present study. It was found that the combination of UV/NaCIO is most efficient, and the color and chemical oxygen demand (COD) removal rate related to different methods decreased in the following order: UV/NaCIO > NaClO >>UV. The decolorization efficiency (99%) was always far higher than that of mineralization (49%) when the model dye solution was treated by UV/NaC1O for 60 mm. In order to address the possible formation of absorbable organic halides (AOX) arised from the use of NaCIO as an oxidant in the present study, DB-56 solution saturated with either O2 or N2 was treated by UV/NaCIO to explore the optimum conditions to minimize the generation of AOX species. The results revealed that AOX species were non-detectable in the UV/NaCIO/O2 system after 60 mm reaction, whereas for UV/NaCIO/N2 system, a fairly large number of AOX was detected by GC/MS. [ABSTRACT FROM AUTHOR]