This study reports on the propranolol (PRO) degradation performance and product toxicity of an ultraviolet light-emitting diode (UV-LED)/chlorine process. The effects of experimental parameters including solution pH, chlorine dosage, and water matrix constituents on PRO removal were evaluated. Up to 94.5% of PRO could be eliminated within 15 min at a PRO-to-chlorine molar ratio of 1:4. The overall removal efficiency of PRO was non-pH dependent in the range of 5-9, while the initial rate was accelerated under alkaline conditions. The presence of Cl-/HCO3- had little influence on the PRO degradation, whereas either humic acid or NO3- had an obvious inhibitory effect. Radical scavenger experiments showed that both HO and Cl primarily contributed to the PRO degradation, and electron paramagnetic resonance data demonstrated the generation of 1O2. The transformation of PRO during this process led to five detected products, which exhibited a higher acute toxicity than the parent compound according to the bright luminescent bacillus T3 method. It is worth mentioning that under the same ultraviolet illumination intensity, the degradation of PRO under UV-LED/chlorine gave a better performance than UV254/chlorine, but the EEO of the former is obviously higher than the latter. So further research is required on improving the electric current to photon conversion efficiency for UV-LED. Additionally, the UV-LED/chlorine system was effective in the degradation of other drugs including sulfamethoxazole, oxytetracycline hydrochloride, and gatifloxacin, suggesting the possible application of the UV-LED/chlorine process for the removal of pharmaceuticals during wastewater treatment.

中文翻译：

---

UV-LED /氯丙醇在水中的降解：降解途径和产物毒性。

这项研究报告了紫外线发光二极管（UV-LED）/氯工艺中普萘洛尔（PRO）的降解性能和产品毒性。评估了实验参数（包括溶液的pH值，氯的用量和水基质成分）对PRO去除的影响。在PRO与氯的摩尔比为1：4的情况下，可以在15分钟内消除高达94.5％的PRO。在5-9范围内，PRO的整体去除效率不受pH值的影响，而在碱性条件下，初始去除速度加快。Cl- / HCO3-的存在对PRO的降解影响很小，而腐殖酸或NO3-则具有明显的抑制作用。自由基清除剂实验表明，HO和Cl均主要是PRO降解的原因，电子顺磁共振数据表明生成了1O2。在此过程中，PRO的转化导致产生了五种检测到的产物，根据明亮的发光芽孢杆菌T3方法，它们的毒性比母体化合物高。值得一提的是，在相同的紫外线照射强度下，UV-LED /氯气对PRO的降解性能优于UV254 /氯气，但前者的EEO明显高于后者。因此，需要进一步研究以提高UV-LED的电流至光子转换效率。此外，UV-LED /氯系统可有效降解包括磺胺甲恶唑，盐酸土霉素和加替沙星在内的其他药物，这表明UV-LED /氯工艺可用于废水处理中的药物去除。