Catalytic effects of nine organic acids on the oxidation of sulfite were compared, in which peracetic acid was the most effective. The intrinsic oxidation kinetics of sodium sulfite catalyzed by peracetic acid were studied using intermittent apparatus, and reaction orders of the reagents and activation energy obtained. Using bubbling apparatus, the macroscopic catalyzed oxidation kinetics of calcium sulfite were investigated by varying pH, concentration of calcium sulfite and peracetic acid, airflow flux and temperature. A mathematical model was established that involved intrinsic reaction, dissolution of calcium sulfite and diffusion of oxygen. It was concluded that the macroscopic reaction is controlled by diffusion of oxygen, which benefits wet flue gas desulfurization. (c) 2007 Elsevier B.V. All rights reserved.