Abstract: Environmental photochemistry of organic pollutants is an important research field, but the ice photochemistry of organic pollutants is still a unknown field and it is attracting more and more attention recently. The ice photochemistry of p-chlorophenol(4-CP), as an important pollutant, is studied a little. In this paper, the UV lamp(125 W high-pressure mercury lamp) was lamp-house and the photoreaction of 4-CP in ice was the object of this research. Some influencing factors and the kinetics and mechanism of the photoconversion was investigated in the range of the temperature of -12—-14 ℃ in the presence of nitrite. According to the results, the initial concentration of the 4-CP, the initial concentration of the nitrite, a commen photoreaction reagent in environment, the initial pH and the intensity of the light had serious effects on the conversion of the 4-CP. The disposal rates of 4-CP and TOC in ice respectively reached 80% and 32% within 180 min. Four reaction products are characterized by MS-GC analysis, it is not completely the same as that reported by other researchers. On this basis the photoconversion mechanism of 4-CP is deduced. It is concluded that the mechanism and photoproducts of 4-CP photoconversion in ice would be changed because of the presence of NO₂^-.

Key words: p-Chlorophenol(4-CP), Nitrite, Ice, Photoconversion, Mechanism