Reactions between some inorganic radicals and oxychlorides studied by pulse radiolysis and laser photolysis

Abstract

Rate constants for the reactions of free radicals, including e _aq ^- , OH, SO ₄ ^- , NO ₃ and Cl ₂ ^- (Cl ^Nsbd ), with oxychloride compounds have been determined. The free radicals were generated by pulse radiolysis and laser photolysis. Most of the reactions have nearly diffusion-controlled rate constants (>10 ⁹ dm3 mol ^-1 s ^-1 ). ClO ^- has relatively higher reactivity than its acid form. e _aq ^- reacts with oxychloride compounds to form their electron adducts which dissociate easily. Electron transfer reactions occur between OH, SO ₄ ^- , NO ₃ and Cl ₂ ^- (Cl ^Nsbd ) radicals and the oxychloride ions. The kinetics results obtained here can be used in simulation work to understand the radiation-induced reactions taking place in groundwater which are relevant to the geological aspects of radioactive waste storage and disposal.