Uptake coefficient of OH radical on aqueous surface Original Research Article

The uptake coefficient of OH radicals on water surface was measured using an impinging flow method with a laser-induced fluorescence method. The uptake coefficient was experimentally determined to be (4.2±2.8)×10−3 under the conditions of the contact time of 115 ms, pH=5.6 and the temperature of 293 K. The uptake coefficient was found to be larger in acidic and alkaline regions than in the neutral region. Negative temperature dependence was also observed. The measured uptake coefficient was fairly well reproduced by the numerical simulation consulting the known reactions of OH radicals in water and the Henryʹs law constant. From the simulation, the accommodation coefficient was estimated to be >0.01 and was possibly close to unity.