Modelling ozone mass transfer in bubble column: determination of the mass transfer coefficient k_La and the consumption of ozone by the water

摘要

The efficiency of the ozonation process depends on the type of contactor and the hydrodynamic behaviour of the gas and liquid phases. Now, the most common contactors are the bubble-diffuser columns. This paper presents the results obtained on a pilot-scale ozone bubble-diffuser contactor (diameter 0.15 m, height 2.3 m) for a continuous operating mode with both co- or counter-current water and gas flows. A computer model based on the establishment of mass balance equations was develped in order to predict following parameters: ozone concentration profiles inside the contactor, ozone residuals, mass transfer coefficient K_La, ozone consumption by water.