School of Environment and Energy, South China University of Technology, Guangzhou, 510006, PR China.
Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Guangdong-Hong Kong, Macao Joint Laboratory for Contaminants Exposure and Health, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou, 510006, China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory of City Cluster Environmental Safety and Green Development, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, China.
Chemosphere. 2022 Oct;305:135440. doi: 10.1016/j.chemosphere.2022.135440. Epub 2022 Jun 23.
The ubiquity of antidepressants in the environment has posed a potential threat to eco-systematic safety. In this study, six kinds of antidepressants including fluoxetine (FLU), paroxetine (PAR), sertraline (SER), fluvoxamine (FLX), citalopram (CTP), and venlafaxine (VEN) were selected to explore their degrading kinetics, transformation pathways, and the acute toxicity of the reaction solution during UV oxidation. The results showed that the order of the photodegradation rate was FLU > PAR > SER > CTP > FLX > VEN. The calculation results of density functional theory (DFT) and molecular orbital theory showed that it was positively correlated with the frontier electron density of drugs and negatively correlated with the HOMO-LUMO gap, respectively. Intermediates were identified with UHPLC-Q-TOF/MS/MS to propose the possible degradation pathways of the drugs and the most likely directions of the reactions were determined by the single point energy calculation. The results of toxicity tests indicated that the acute toxicity of the reaction solution of PAR did not change significantly. The photolysates toxicity of FLU, SER, and FLX decreased at the end of the reaction, while that of CTP and VEN was increased by 1.5 and 1.3 times compared with the parent compound, respectively. Toxicity predictions by the quantitative structure activity relationship (QSAR) model showed that except FLU-162, FLX-174, and VEN-230, other degradation products have developmental toxicity. The results revealed the transformation pathways of these drugs under the UV disinfection process in wastewater treatment plants, especially the formation of toxic by-products during the disinfection process.
环境中抗抑郁药的普遍存在对生态系统安全构成了潜在威胁。在本研究中，选择了六种抗抑郁药，包括氟西汀（FLU）、帕罗西汀（PAR）、舍曲林（SER）、氟伏沙明（FLX）、西酞普兰（CTP）和文拉法辛（VEN），以探索它们在 UV 氧化过程中的降解动力学、转化途径和反应溶液的急性毒性。结果表明，光降解速率的顺序为 FLU > PAR > SER > CTP > FLX > VEN。密度泛函理论（DFT）和分子轨道理论的计算结果表明，它与药物的前沿电子密度呈正相关，与 HOMO-LUMO 能隙呈负相关。利用 UHPLC-Q-TOF/MS/MS 鉴定了中间体，提出了药物的可能降解途径，并通过单点能计算确定了反应的最可能方向。毒性测试结果表明，PAR 反应溶液的急性毒性没有明显变化。FLU、SER 和 FLX 的光解产物毒性在反应结束时降低，而 CTP 和 VEN 的毒性分别比母体化合物增加了 1.5 倍和 1.3 倍。定量结构活性关系（QSAR）模型的毒性预测表明，除了 FLU-162、FLX-174 和 VEN-230 外，其他降解产物具有发育毒性。这些结果揭示了这些药物在污水处理厂 UV 消毒过程中的转化途径，特别是在消毒过程中形成有毒副产物。
