School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan, 430074, China; Center for the Environmental Implications of Nanotechnology (CEINT), Durham, 27708-0287, USA.
School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan, 430074, China.
Chemosphere. 2019 Oct;233:282-291. doi: 10.1016/j.chemosphere.2019.05.201. Epub 2019 May 29.
Degradation of imipramine (IMI) in the VUV system (VUV + UV) was firstly evaluated in this study. Both HO oxidation and UV direct photolysis accounted for IMI degradation. The quantum yields of UV direct photolysis of deprotonated and protonated IMI were 1.31×10 and 3.31×10, respectively, resulting in the higher degradation efficiency of IMI at basic condition. Increasing the initial IMI concentration lowered the degradation efficiency of IMI. While elevating reaction temperature significantly improved IMI degradation efficiency through the promotion of both the quantum yields of HO and the UV direct photolysis rate. The apparent activation energy was calculated to be about 26.6 kJ mol. Negative-linear relationships between the k of IMI degradation and the concentrations of HCO/CO, NOM and Cl were obtained. The degradation pathways were proposed that cleavage of side chain and hydroxylation of iminodibenzyl and methyl groups were considered as the initial steps for IMI degradation in the VUV system. Although some high toxic intermediate products would be produced, they can be further transformed to other lower toxic products. The good degradation efficiency of IMI under realistic water matrices further suggests that the VUV system would be a good method to degrade IMI in aquatic environment.
本研究首次评估了在 VUV 体系（VUV+UV）中降解丙咪嗪（IMI）的情况。HO 氧化和 UV 直接光解均参与了 IMI 的降解。去质子化和质子化 IMI 的 UV 直接光解量子产率分别为 1.31×10 和 3.31×10，导致碱性条件下 IMI 的降解效率更高。增加初始 IMI 浓度会降低 IMI 的降解效率。而升高反应温度则通过促进 HO 的量子产率和 UV 直接光解速率来显著提高 IMI 的降解效率。表观活化能约为 26.6 kJ/mol。IMI 降解的 k 值与 HCO/CO、NOM 和 Cl 的浓度之间呈负线性关系。提出了降解途径，认为在 VUV 体系中，侧链的断裂和亚氨基二苯甲基和甲基的羟化被认为是 IMI 降解的初始步骤。尽管会产生一些高毒性的中间产物，但它们可以进一步转化为其他低毒性的产物。在实际水基质中 IMI 具有良好的降解效率进一步表明，VUV 体系是降解水环境中 IMI 的一种很好的方法。
