Study on the synergistic oxidation of sulfite solution by ozone and oxygen: Kinetics and mechanism

Abstract

Kinetics for the synergistic oxidation of sulfite containing solution by ozone and oxygen was studied in this work. A model including the macro oxidation of sulfite solution, the gas–liquid mass transfer of ozone and oxygen, and chemical reaction in the liquid phase was developed and established. The model considered the following variables: sulfite concentration, partial pressure of ozone or oxygen, pH of the sulfite solution, ionic strength of the medium, reaction temperature, and residence time. For the oxidation processes, mass transfer of oxygen was found to be the rate-determining step as the transfer of ozone and chemical transformation was found to proceed rapidly. In addition, the simulation results for the oxidation rates obtained from this model via comparison of the experimental results with the predicted values were found to be acceptable. The developed kinetic model is beneficial for further understanding of the oxidation mechanism of sulfite solution.