title: The photoconversion of gamma-hexachlorocyclohexane under UV irradiation in water, snow and ice.
abstract: The photochemistry of organic pollutants has received increasing attention in ice and snow. In this work, the photoconversion of gamma-hexachlorocyclohexane (γ-HCH) under UV irradiation was investigated in water, snow and ice. The photoconversion rate, products and mechanisms were inspected, and the effect of inorganic ions (NO2(-), NO3(-), HCO3(-) and Fe(2+)) was discussed. The results showed that γ-HCH could be photoconverted in water, snow and ice, with the photoconversion rate being fastest in snow, and slowest in ice. All photoconversion could be described by the first-order kinetics model. In water, snow and ice, the common photoproducts of γ-HCH were alpha-hexachlorocyclohexane (α-HCH) and pentachlorocyclohexene. α-HCH was generated by a change in the bonding of a chlorine atom in γ-HCH; pentachlorocyclohexene was generated by the removal of a molecule of chlorine hydride from a molecule of γ-HCH. Different concentrations of NO2(-), NO3(-) and HCO3(-) all inhibited the photoconversion of γ-HCH, and the inhibition effect decreased with increasing concentrations of NO2(-) and NO3(-), but increased with the increasing concentrations of HCO3(-). Different concentrations of Fe(2+) promoted the photoconversion of γ-HCH in water and ice, but had little effect in snow.
authors: Key Laboratory of Songliao Aquatic Environment, Ministry of Education, Jilin Jianzhu University, Changchun 130118, China; Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China E-mail: kangcl@jlu.edu.cn.
authors: Honghai
authors: H
authors: Xue
authors: Key Laboratory of Songliao Aquatic Environment, Ministry of Education, Jilin Jianzhu University, Changchun 130118, China; Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China E-mail: kangcl@jlu.edu.cn.
authors: Xiaojian
authors: X
authors: Tang
authors: Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China E-mail: kangcl@jlu.edu.cn.
authors: Chunli
authors: C
authors: Kang
authors: Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China E-mail: kangcl@jlu.edu.cn.
authors: Jia
authors: J
authors: Liu
authors: Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China E-mail: kangcl@jlu.edu.cn.
authors: Lei
authors: L
authors: Shi
authors: Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China E-mail: kangcl@jlu.edu.cn.
authors: Hongliang
authors: H
authors: Wang
authors: Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China E-mail: kangcl@jlu.edu.cn.
authors: Ting
authors: T
authors: Yang
mesh_terms: D004785:Environmental Pollutants / Q000737:chemistry* / Q000528:radiation effects; D001556:Hexachlorocyclohexane / Q000737:chemistry* / Q000528:radiation effects; D007053:Ice; D010782:Photolysis; D012914:Snow; D014466:Ultraviolet Rays
chemical_list: D004785:Environmental Pollutants; D007053:Ice; D001556:Hexachlorocyclohexane