Oxidation of sulfite is an important process in wet flue gas desulfurization. The intrinsic kinetics of sulfite oxidation with inhibitor of phenol was experimentally studied in an intermittent apparatus, indicating that the complicated reaction proceeded with two steps, a rapid reaction in rich oxygen zone and a slow reaction in poor oxygen zone. In the rich oxygen zone, the reaction order is －0.5 for phenol, 1.0 for sulfite, and 2.0 for dissolved oxygen, and the activation energy is 99.2 kJ•mol－1. In the poor oxygen zone, the reaction order is －0.5 for phenol, 1.5 for sulfite, and 0.0 for dissolved oxygen, and the activation energy is 129.7 kJ•mol－1. Integrated with the experimental results, the macroscopical kinetics of sulfite oxidation with the inhibitor of phenol was deduced.

Key words: phenol, sulfite, oxidation, inhibition, kinetics