Glucocorticoids (GCs) have drawn great concern due to widespread contamination in the environment and application in treating COVID-19. This work aimed to compare the performance of UVA/chlorination and ozonation on GC removal in terms of removal efficiency, degradation pathway, and toxicity change, with fluocinolone acetonide (FA), triamcinolone acetonide (TA), and clobetasol propionate (CP) as target compounds. The results showed that both UVA/chlorination and ozonation could degrade GCs. Compared with UVA/chlorination (removal efficiency of 89% for FA, 86% for TA, and 90% for CP at 7 h), ozonation (removal efficiency of 90% for FA, 96% for TA, and 98% for CP at 15 min) was more effective in GC removal. Photodegradation contributed most to GC removal during UVA/chlorination, while O₃ molecules were the main functional species during ozonation. H-abstraction, dechlorination, carbon–carbon bond cleavage, and ester hydrolysis were proposed for both UVA/chlorination and ozonation based on the identification of intermediates. However, ozone tended to attack C=C double bonds, resulting in the cracked benzene ring of GCs, while chlorine was more likely to attack alcohol and ketone groups. Although most GCs were removed during ozonation and UVA/chlorination, their acute toxicities slightly declined. Compared with UVA/chlorination, ozonation was more effective in toxicity reduction.

中文翻译：

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UVA/氯化和臭氧去除糖皮质激素的评估：动力学、降解途径和毒性的性能比较

由于环境中的广泛污染和在治疗 COVID-19 中的应用，糖皮质激素 (GC) 引起了极大的关注。本工作旨在比较 UVA/氯化和臭氧对 GC 去除的去除效率、降解途径和毒性变化的性能，以氟轻松 (FA)、曲安奈德 (TA) 和丙酸氯倍他索 (CP) 为目标化合物。结果表明，UVA/氯化和臭氧化都可以降解 GC。与 UVA/氯化（FA 的去除效率为 89%，TA 的去除效率为 86%，CP 的去除效率为 7 小时）相比，臭氧化（FA 的去除效率为 90%，TA 的去除效率为 96%，CP 的去除效率为 98% 15 分钟）更有效地去除 GC。在 UVA/氯化过程中，光降解对 GC 去除的贡献最大，而 O ₃分子是臭氧化过程中的主要功能物种。基于中间体的鉴定，提出了用于 UVA/氯化和臭氧化的 H 提取、脱氯、碳-碳键断裂和酯水解。然而，臭氧倾向于攻击C=C双键，导致GC的苯环破裂，而氯更容易攻击醇和酮基团。尽管大多数 GC 在臭氧化和 UVA/氯化过程中被去除，但它们的急性毒性略有下降。与UVA/氯化相比，臭氧在降低毒性方面更有效。