Acid red 73 (AR73) is a representative dye pollutant that poses a threat to the environment and human health. Effectively removing this type of pollutant by conventional processes is difficult. However, this study found that compared with UV/PDS, UV/O₃, and PDS/O₃, UV/O₃/PDS composite system had the highest degradation effect on AR73. The degradation efficiency in the composite system reached 97.61% within 30 min, and the synergistic coefficients in the composite system were all greater than 1. In the UV/O₃/PDS system, ·OH was the main free radical that mainly degrades AR73. The increase of PDS dosage promoted the degradation of AR73, but the increase of O₃ dosage was difficult to greatly improve the degradation of AR73 effect. The kinetic model of the apparent reaction rate was determined. The UV/O₃/PDS system can efficiently degrade AR73 in a wide range of substrate concentrations and pH levels, and at the same time showed good adaptability to various concentrations of anions (Cl⁻, CO₃²⁻, SO₃²⁻, and C₂O₄²⁻). Under raw water quality, the degradation effect of AR73 was still as high as approximately 90%. The theoretical attack site was obtained by DFT calculation, and the possible degradation pathway of AR73 was proposed based on the GC-MS spectrum and UV–Vis absorption spectrum. The attack of –NN- by ·OH, SO₄⁻, and O₃ was proposed to be the main possible degradation pathway for AR73. Therefore, this study further improves the understanding of the UV/O₃/PDS system and shows the potential applicability of this system in the treatment of dye wastewater.

酸性红73（AR73）是一种代表性染料污染物，对环境和人类健康构成威胁。传统工艺很难有效去除这类污染物。但本研究发现，与UV/PDS、UV/O ₃和PDS/O ₃相比，UV/O ₃ /PDS复合体系对AR73的降解效果最高。30 min内复合体系的降解效率达到97.61%，复合体系的协同系数均大于1。在UV/O ₃ /PDS体系中，·OH是主要降解AR73的主要自由基。PDS用量的增加促进了AR73的降解，但O _3的增加剂量很难大幅度提高AR73的降解效果。确定了表观反应速率的动力学模型。UV/O ₃ /PDS体系可在广泛的底物浓度和pH值范围内高效降解AR73，同时对各种浓度的阴离子（Cl ^-、CO ₃ ²⁻、SO ₃ ²⁻、和 C ₂ O ₄ ²⁻）。在原水水质下，AR73的降解效果仍高达90%左右。通过DFT计算得到理论攻击位点，并基于GC-MS光谱和UV-Vis吸收光谱提出了AR73可能的降解途径。-N的攻击N- 被·OH、SO ₄ ^-和O ₃提出是AR73 的主要可能降解途径。因此，本研究进一步提高了对UV/O ₃ /PDS系统的认识，并展示了该系统在处理染料废水中的潜在适用性。