Antibiotics are frequently detected in water, which can pose a great threat to human health. In this paper, an ultraviolet/persulfate (UV-C/PS) advanced oxidation process was utilized to remove a common antibiotic sulfachloropyridazine (SCP) efficiently from groundwater. The degradation mechanism and kinetics were investigated by researching several key influencing factors, including two radical scavengers (tert-butanol and methyl alcohol), dosages of PS, initial pH, anions (H₂PO₄⁻, HPO₄²⁻, Cl⁻, HCO₃⁻ and NO₃⁻) and natural organic matter. The degradation of SCP followed a pseudo-first-order kinetic model and better degradation was achieved in acidic conditions than in alkaline conditions. The effect of scavengers indicated that both SO₄⁻˙ and HO˙ contributed to the degradation of SCP and SO₄⁻˙ played a major role. The degradation rate constants of SCP with SO₄⁻˙ and HO˙ at the initial pH of 6.3 were calculated to be k_SCP,HO˙ = 0.867 × 10⁹ M⁻¹ s⁻¹ and k_SCP,SO4⁻˙ = 3.073 × 10⁹ M⁻¹ s⁻¹ in the UV-C/PS system by the relative rate method. Increasing the concentration of PS obviously facilitated the degradation and mineralization rates of SCP, which could reach 100% and 90%, respectively, at a PS dosage of 4.0 mM after 2 h. Also, H₂PO₄⁻ and Cl⁻ promoted the degradation of SCP, whereas the removal of SCP was restrained by the addition of HPO₄²⁻, HCO₃⁻ and large dosages of NO₃⁻. The proposed degradation pathway of SCP was obtained by analyzing the intermediates.

中文翻译：

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UV-C /过硫酸盐降解磺胺氯哒嗪的动力学，关键因素，降解途径

水中经常检测到抗生素，这可能对人类健康构成巨大威胁。本文采用紫外/过硫酸盐（UV-C / PS）高级氧化工艺从地下水中有效去除常见的抗生素磺胺氯哒嗪（SCP）。通过研究几个关键影响因素，其中包括两个自由基清除剂（降解机理和动力学进行了研究叔丁醇和甲醇），PS的剂量，初始pH值，阴离子（H ₂ PO ₄ ^-，HPO ₄ ^2-，氯^- ，HCO ₃ ^-和NO ₃ ^-）和天然有机物。SCP的降解遵循伪一级动力学模型，在酸性条件下比在碱性条件下可实现更好的降解。清除剂的作用表明，SO ₄ ^- ˙和HO˙均对SCP的降解有贡献，而SO ₄ ^- ˙则起着主要作用。计算出在初始pH值为6.3时具有SO ₄ ^- ˙和HO˙的SCP的降解速率常数为k _SCP，HO˙ = 0.867×10 ⁹ M ^-1 s ^-1和k _{SCP，SO 4 ^- ˙} = 3.073 ×10 ⁹ M ^-1秒在UV-C / PS系统中，采用相对速率法测定^-1。PS浓度的增加明显促进了SCP的降解和矿化率，在2 h后以4.0 mM的PS剂量分别可达到100％和90％。此外，H ₂ PO ₄ ^-和Cl ^-促进SCP的降解，而SCP的除去通过加入HPO的抑制₄ ^2-，HCO ₃ ^-和NO的大剂量₃ ^- 。通过分析中间体获得了拟议的SCP降解途径。