Urea is one of the most important nitrogenous organic pollutants in water, and its removal attracts attention because of a growing concern related to water eutrophication. Urea has previously been considered to be largely unaffected by the UV-chlorine process. However, N-chlorourea, an intermediate of urea chlorination, has been shown to absorb ultraviolet radiation, and as such its photolysis is possible. Experiments were conducted to quantify the kinetics of N-chlorourea degradation under UV₂₅₄ irradiation. The results showed that about 92% of N-chlorourea was degraded under UV₂₅₄ irradiation. Ammonia and nitrate were detected as the primary nitrogen containing products of the photolysis of N-chlorourea. Solution pH ranging from 3.0 to 7.5 influenced the distribution of these products but not on the degradation rate. Based on these data, a possible pathway of photodegradation of N-chlorourea under UV₂₅₄ is proposed. The degradation of urea was also achieved by the photolysis of N-chlorourea during the combined pre-chlorination and UV₂₅₄ process. Insights gained in this study may be useful for exploring the potential of combined pre-chlorination and UV₂₅₄ process on urea removal in water treatment.

尿素是水中最重要的含氮有机污染物之一，由于对水富营养化的关注日益增加，因此尿素的去除引起了人们的关注。尿素以前被认为在很大程度上不受紫外线-氯工艺的影响。然而，已显示出尿素氯化的中间体N-氯脲吸收紫外线，因此其光解是可能的。进行实验以量化在UV ₂₅₄照射下N-氯脲降解的动力学。结果表明，在UV ₂₅₄照射下，约92％的N-氯脲被降解。检测到氨和硝酸盐是N光解的主要含氮产物-氯脲。溶液的pH值在3.0到7.5范围内会影响这些产品的分布，但不会影响降解速率。基于这些数据，提出了在UV ₂₅₄下N-氯脲光降解的可能途径。在联合预氯化和UV ₂₅₄工艺过程中，N-氯脲的光解也可实现尿素的降解。这项研究中获得的见解可能对于探索预氯化和UV _254组合工艺对水处理中尿素去除的潜力很有用。