Absorption of sulfur dioxide into aqueous solutions containing hydrogen peroxide results in the irreversible oxidation to sulfuric acid. As shown in previous works, the absorption rate increases with the concentration of oxidizing agent but decreases with the rise of acidity. This paper presents a thorough kinetic investigation of the liquid-phase reaction Of SO2 for a wide range of H2O2 and H2SO4 concentrations. Absorption of sulfur dioxide was carried out at 20 degrees C in a pilot-scale packed column. The experimental data were modelled thanks to the theory of absorption in the fast or moderately fast chemical reaction regimes defined by classical Hatta numbers and depending on the H2O2 concentration at a given acidity. For both regimes, a satisfactory agreement was obtained between experimental results and predictions of models including original values of kinetic parameters. (c) 2005 Elsevier Ltd. All rights reserved.