中文摘要：

研究了模拟太阳光-NO2-作用下冰中γ-六六六（γ-HCH）的光解动力学和机理。结果发现，模拟太阳光-NO2-作用下冰中γ-HCH能够快速光解；且光解过程符合一级动力学方程。 HCO3-和Fe3＋抑制了γ-HCH的光解；强酸性条件有利于γ-HCH的光解，中性及碱性条件影响不大。模拟太阳光-NO2-作用下冰中γ-HCH光解产物为一氯酚、四氯环己烯和五氯环己烯，主要光解机制为脱氯及羟基取代。研究结果对于深入认识亚硝酸根的光敏化作用以及γ-HCH的环境行为具有重要意义。

英文摘要：

The photolysis kinetics and mechanism of γ-HCH in ice by the simulated sunlight with the presence of nitrite was studied. The results showed thatγ-HCH photolysis occured in this system, and it obeyed the first-or-der kinetics. Dicarbonate and ferric ion inhibited the photolysis ofγ-HCH;the strong acidic condition was in favor of the photolysis, while neutral and alkaline conditions had little effect. The photolysis products ofγ-HCH detected were chlorophenol, tetrachlorocyclohexene and pentachlorocyclohexene, and the main photolysis mechanism was dechlorination and hydroxy substitution. The results help to understand the photosensitization of nitrite, as well as the environmental behavior of γ-HCH.