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光化学降解是表层水体中抗生素类污染物的重要消减方式.研究了水中代表性唑烷酮类抗生素利奈唑酮的光降解动力学、影响因素与转化产物.模拟日光(λ>290nm)照射下,利奈唑酮的光解遵循准一级反应动力学,纯水中表观光解量子产率为0.834±0.054;与纯水中相比,淡水、海水中光解较慢,这归因于水中常见溶解性物质的影响.pH,Cl–和海水盐度对光解动力学无显著影响(P>0.05),但腐殖酸、NO3–和Fe(III)通过光掩蔽等效应显著抑制其光降解猝灭实验表明,模拟日光和UV-vis(λ>200nm)照射下,利奈唑酮发生了直接光解及1O2参与的自敏化光解,表现为光解速率常数与初始浓度呈负相关.两种光源照射下,主要光解产物和途径均有差别,UV-vis光照下主要发生了脱氟和光致水解,而在模拟日光照射下发生了吗啉环脱氢等反应.
Photochemical degradation is an important way to abate antibiotic pollutants in surface water.The photodegradation kinetics, influencing factors and conversion products of linezolid, a representative oxazolidinone in water, were studied.Under simulated sunlight (λ> 290nm) irradiation, The photolysis of linezolid followed the first order reaction kinetics and the apparent photolysis yield of pure water was 0.834 ± 0.054. Compared with pure water, the photolysis of fresh water and seawater was slower, which was attributed to the common (P> 0.05). However, the photosynthetic kinetics of humic acid, NO3- and Fe (III) significantly inhibited their photodegradation Quenching experiments showed that the direct photolysis and the self-sensitized photolysis with 1O2 occurred under the illumination of simulated sunlight and UV-vis (λ> 200nm). The results showed that the photolysis rate constant was negatively correlated with the initial concentration. Under the irradiation of two light sources, the main photolysis products and pathways are different. Under the UV-vis light irradiation, defluorination and photolysis mainly occurred, and the morpholine ring dehydrogenation reaction occurred under simulated sunlight.