• 关键词：糖精  紫外  过氧化氢  过硫酸盐  动力学  降解路径

• 基金项目：国家自然科学基金（No.51525806，51878648）；北京城市学院2019年度实培计划项目

• 段书乐
• 1. 中国矿业大学(北京), 化学与环境工程学院, 北京 100083;2. 中国科学院生态环境研究中心, 中国科学院饮用水科学与技术重点实验室, 北京 100085

• 马婧捷
• 北京城市学院, 城市建设学部, 北京 100191

• 党宁
• 中国矿业大学(北京), 化学与环境工程学院, 北京 100083

• 黄艳超
• 北京城市学院, 城市建设学部, 北京 100191

• 董慧峪
• 中国科学院生态环境研究中心, 中国科学院饮用水科学与技术重点实验室, 北京 100085

• 侯嫔
• 中国矿业大学(北京), 化学与环境工程学院, 北京 100083

• 强志民
• 中国科学院生态环境研究中心, 中国科学院饮用水科学与技术重点实验室, 北京 100085

• 摘要：人工甜味剂（ASs）作为一类新兴污染物在世界范围内的各种水体中被广泛检出，本文选取具有代表性的糖精（SAC）作为研究对象，探讨了紫外/过氧化氢（UV/H₂O₂）和UV/过硫酸盐（PS）两种高级氧化工艺（AOPs）降解SAC的动力学、影响因素、矿化率、转化产物和降解机制.结果表明：单独的UV、PS和H₂O₂对SAC的去除效果有限（去除率<5%），UV/H₂O₂和UV/PS工艺对SAC的去除效果良好（去除率>99%）且降解符合伪一阶动力学，速率分别为0.38 min^-1和0.09 min^-1.降低溶液pH值、增大PS浓度均可促进SAC降解；但随着H₂O₂浓度的升高，SAC降解效率先增加后减小.相比UV/PS工艺，UV/H₂O₂工艺降解SAC的矿化率更高（可达43%）.产物鉴定结果表明，两种UV-AOPs氧化降解SAC均会生成开环产物，表明反应会破坏SAC分子中的N—S结构.此外，UV/H₂O₂工艺更易生成羟基化产物，二聚体产物仅在UV/PS工艺中被检测到.

• Abstract：Artificial sweeteners (ASs), are a class of emerging pollutants, which are widely detected in various water samples around the world. Using saccharin (SAC) as the representative ASs, the kinetics, influencing factor, mineralization rate, degradation products and mechanisms by ultraviolet/hydrogen peroxide (UV/H₂O₂) and UV/persulfate (PS) were investigated in this study. The results showed that the removals of SAC by UV, PS and H₂O₂ alone were limited (<5%), but exhibited significant removal (>99%) in UV/H₂O₂ and UV/PS processes. The pseudo-first-order degradation rates of SAC were determined to be 0.38 min^-1 and 0.09 min^-1 in UV/H₂O₂ and UV/PS processes, respectively. Both decreasing solution pH and increasing PS dosage enhanced the oxidation of SAC significantly. However, the degradation of SAC increased first and then decreased with increasing initial H₂O₂ concentration. Compared with UV/PS process, UV/H₂O₂ process degraded SAC with higher mineralization rate (up to 43%). The ring-opening products of SAC were observed in both UV-based processes, indicating that the N—S structure in the SAC molecule was damaged after the oxidation. In addition, the hydroxylated products were prone to form in UV/H₂O₂ process, and the dimer product was only observed in UV/PS process.

• Key words：saccharin  ultraviolet  hydrogen peroxide  persulfate  kinetics  degradation pathway

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