E. Kwok, R. Atkinson, J. Arey
Jun 1, 1995
Citations
3
Influential Citations
97
Citations
Quality indicators
Journal
Environmental science & technology
Abstract
Rate constants for the gas-phase reactions of 2,2'-, 3,3'-, and 3,5-dichlorobiphenyl, 1-chlorodibenzo-p-dioxin, 1,2-dimethoxybenzene, and diphenyl ether with the OH radical have been determined at 297 ± 2 K and atmospheric pressure of air using a relative rate method. The rate constants forthe OH reactions were (in cm 3 molecule -1 s -1 units) as follows : 2.0 x 10 -12 for 2,2'-dichlorobiphenyl ; 4.1 x 10 -12 for 3,3'-dichlorobiphenyl ; 4.2 x 10 -12 for 3,5-dichlorobiphenyl ; 4.7 x 10 -12 for 1-chlorodibenzo-p-dioxin ; 3.5 x 10 -11 for 1,2-dimethoxybenzene ; and 9.6 x 10 -12 for diphenyl ether. The reactions of NO 3 radicals and O 3 with 1-chlorodibenzo-p-dioxin and 2,2'-dichlorobiphenyl were also investigated, and upper limits to the rate constants for the reactions of O 3 with 1-chloro-dibenzo-p-dioxin and 2,2'-dichlorobiphenyl of <7 x 10 -20 cm 3 molecule -1 s -1 and <2 x 10 -20 cm 3 molecule -1 s -1 , respectively, were obtained. The reaction mechanism of the NO 3 radical with 1-chlorodibenzo-p-dioxin is discussed ; no reaction with 2,2'-dichlorobiphenyl was observed. The kinetic data for the OH radical reactions, together with those previously obtained for the reactions of the OH radical with dibenzo-p-dioxin, dibenzofuran, biphenyl, and the monochlorobiphenyls, were used to revise a previous method for calculating the OH radical reaction rate constants and, hence, atmospheric lifetimes for the PCBs, PCDDs, and PCDFs.