RADIATION-INDUCED OXIDATION OF HSO3- IN AQUEOUS-SOLUTION

Kinetics of HSO3- oxidation under e-beam irradiation has been studied. The ranges of main parameters: initial bisulfite concentration-2 x 10 (-4)-3 x 10(-2) M, pH almost-equal-to 2-4, dose rate-I = 10(-3) - 10 k Gy s-1. The stoichiometry of HSO3- oxidation in deaerated and aerated solutions was established. In deaerated solution the competition of re actions of H atoms with HSO3- (k1) and SO2 (k2) was observed. The esti mated rate constants: k1 of order 10(7) and k2 of order 5 x 10(7) M-1 s-1. It was found that only sulfate has been produced in SO3- radicals self-recombination. For aerated solution at 1 less-than-or-equal-to 1 0(-1) kGy s-1 HSO3- oxidation proceeds in degenerated chain regime wit h main termination reaction HO2 + SO5- and maximum chain length almost -equal-to 10. The influence of mass-transfer processes to the oxidatio n rate in thin water film in a contact with gas mixture air-SO2 has be en also investigated.