To discover an applicable technology for urea abatement from swimming pool water (SPW), this study compared the performances of seven ultraviolet (UV)-based technologies on urea removal, including UV alone, UV coupled with hydrogen peroxide (UV/H₂O₂), sulfite (UV/Na₂SO₃), potassium persulfate (UV/K₂S₂O₈), a combination of UV and vacuum UV (UV/VUV), and UV/VUV in tandem with either H₂O₂ (VUV/H₂O₂) or potassium persulfate (VUV/K₂S₂O₈). Among them, UV and UV/Na₂SO₃ showed little removal ability, and UV/H₂O₂ removed only 12.8% of urea within 3-h experiments, while UV/VUV degraded 71.7% of urea without introducing substantial total dissolved solids (TDS). Therefore, UV/VUV was considered as a promising technology for further exploration. In comparison, although UV/K₂S₂O₈ exhibited higher urea removal than UV/VUV, it caused dramatic increases of TDS, which made the regulatory threshold for the TDS increment difficult to maintain. Within UV/VUV studies, some common components in SPW (e.g., cyanuric acid, humic acid, nitrate, and bicarbonate) inhibited the removal process, whereas chloride and sulfate facilitated it, while free chlorine at doses ≤ 3 mg-Cl₂/L and pH levels from 6.8 to 8.0 imposed little impact on urea degradation. Overall, UV/VUV degraded 40.0% and 22.2% of urea from tap water and SPW, respectively; both were lower than the efficiency observed in ultrapure water. As for reaction byproducts, urea phototransformation via UV/VUV yielded nitrate and ammonia as the key products with the mass balance of nitrogen element being met. However, the contents of organic carbon decreased at a rate slightly lower than urea degradation, suggesting that urea was mostly mineralized and slightly converted to unknown organic compounds. The results hence demonstrate that UV/VUV is an effective alternative for urea removal from SPW.

为了找到一种适用于游泳池水（SPW）减排尿素的技术，本研究比较了七种基于紫外线（UV）的技术在尿素去除方面的性能，包括仅紫外线，结合紫外线与过氧化氢（UV / H ₂ O _2）），亚硫酸盐（UV / Na ₂ SO ₃），过硫酸钾（UV / K ₂ S ₂ O ₈），UV和真空UV（UV / VUV）的组合，以及与H ₂ O ₂串联的UV / VUV （VUV / H ₂ O ₂）或过硫酸钾（VUV / K ₂ S ₂ O ₈）。其中，UV和UV / Na ₂在3小时的实验中，SO _3的去除能力很小，UV / H ₂ O ₂仅去除了12.8％的尿素，而UV / VUV降解了71.7％的尿素而未引入大量的总溶解固体（TDS）。因此，UV / VUV被认为是进一步探索的有前途的技术。相比之下，虽然UV / K ₂ S ₂ O ₈具有比UV / VUV高的尿素去除率，这导致TDS急剧增加，这使得TDS增量的调节阈值难以维持。在UV / VUV研究中，SPW中的一些常见成分（例如氰尿酸，腐殖酸，硝酸盐和碳酸氢盐）抑制了去除过程，而氯化物和硫酸盐则促进了去除过程，而游离氯的剂量≤3 mg-Cl ₂/ L和pH值从6.8到8.0对尿素降解几乎没有影响。总体而言，UV / VUV分别从自来水和SPW中降解了40.0％和22.2％的尿素。两者均低于超纯水中观察到的效率。对于反应副产物，通过UV / VUV进行的尿素光转化产生了作为主要产物的硝酸盐和氨，同时满足了氮元素的质量平衡。但是，有机碳的含量下降的速度略低于尿素降解的速度，这表明尿素主要是矿化的，并轻微转化为未知的有机化合物。因此，结果表明，UV / VUV是从SPW去除尿素的有效替代方法。