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羟基多环芳烃(OH-PAHs)是PAHs羟基化的一类新型污染物,广泛存在于水、大气等环境介质中,并潜在存在于极地冰雪中,研究其环境行为和毒理效应具有重要意义.以9-羟基芴(9-OHFL)为模型化合物,考察了光照(λ>290 nm)作用下冰中9-OHFL的光降解动力学、影响因素、转化产物及光修饰毒性.9-OHFL的光降解遵循准一级反应动力学,纯水冰中速率常数为0.0092 min-1,表观光解量子产率为0.022.外推至实际环境,南极长城站附近夏天中午冰雪表面9-OHFL的半减期为54 h.与纯水冰中相比,海水冰、淡水冰中光降解较快,这归因于水中主要溶解性物质的影响,Cl-,NO3-,Fe(III)及低浓度腐殖酸均可促进9-OHFL的光降解.通过GC-MS/MS分析,纯水冰中9-OHFL光化学转化生成了5种主要产物,涉及的转化路径为脱氢氧化、异构化和苯环羟基化.毒性实验表明,9-OHFL对发光菌(Vibrio fischeri)表现为光修饰毒性.本研究所揭示的9-OHFL光降解规律和光化学转化风险对于极地冰雪环境中OH-PAHs类污染物的归趋和风险评价具有重要意义.
Hydroxy polycyclic aromatic hydrocarbons (OH-PAHs) are new types of PAHs hydroxylation of a new type of pollutants, widely exist in water, atmosphere and other environmental media, and the potential exists in polar ice and snow, to study its environmental behavior and toxicological effects of great significance 9-OHFL (9-OHFL) was used as a model compound to investigate the photodegradation kinetics, influencing factors, conversion products and photo-induced toxicity of 9-OHFL in ice under irradiation of light (λ> 290 nm) The photodegradation followed the quasi-first order reaction kinetics, the rate constant of pure water ice was 0.0092 min-1, and the apparent photolysis quantum yield was 0.022. Extrapolating to the actual environment, the surface of the Antarctic Great Wall near the summer noon ice and snow 9-OHFL The half-time period was 54 h. Compared with pure ice, photodegradation of seawater ice and freshwater ice was faster, due to the influence of major dissolved substances in water, such as Cl-, NO3-, Fe (III), and low The concentration of humic acid can promote the photodegradation of 9-OHFL. By GC-MS / MS analysis, photochemical conversion of 9-OHFL in pure water ice generated five main products, the conversion path involved dehydrogenation, isomerization And the hydroxylation of benzene ring.The toxicity experiments showed that 9-OHFL showed photo-modification toxicity to Vibrio fischeri.The present study revealed that 9-OHFL optical and photochemical conversion and degradation of important risk and risk assessment for the fate OH-PAHs pollutant in the polar ice environment.