Evaluation of Solubility and the Gas-Liquid Equilibrium Coefficient of High Concentration Gaseous Ozone to Water

摘要

Solubility and the gas-liquid equilibrium coefficient of gaseous ozone to water were examined under higher concentrations of supplied gaseous ozone up to 100 mg/L. The experimental and modeling approach was employed to evaluate the gas-liquid equilibrium coefficients and mass transfer of ozone. The gas-liquid equilibrium coefficients were evaluated as 0.35, 0.31 and 0.25 (mg/L-liquid) / (mg/ L-gas) at 15, 20 and 30 °C, respectively. These gas-liquid equilibrium coefficients are applicable for the wide concentration range of supplied ozone gas up to 100 mg/L. The calculation result by a model which has terms of the mass transfer of ozone, the gas-liquid equilibrium coefficient and the rate of ozone self-decomposition, was examined and had a good agreement with the experimental data over the wide range of temperatures, pHs, inorganic carbon concentrations and supplied ozone gas concentrations. The rate of ozone self-decomposition evaluated separately from this study was employed for the calculation. We can conclude that absorption of gaseous ozone to water is expressed by the three terms mentioned above when the rate of ozone self-decomposition is evaluated properly. In sensitive analysis, we elucidated that the rate of ozone self-decomposition affected strongly on the concentration of dissolved ozone at steady-state under higher concentration of supplied gaseous ozone.