Development and Experimental Validation of the Model of a Tall, Continuous-Flow, Countercurrent, Bubble-Type Ozone Contactor

The objective of this study was the development of a fully mechanistic model for the description of ozone mass transfer from gaseous to aqueous phase and the aqueous-phase ozone decomposition in a continuous-flow, countercurrent, tall, bubble-type ozone contactor. The developed model was used to simulate the effects of changes in aqueous-phase pH and scavenger concentration on ozone mass transfer and decomposition. Simulation results could be adequately explained based on the current understanding of ozone mass transfer and aqueous ozone chemistry. Experimental determination of steady-state aqueous ozone profiles and corresponding effluent gaseous ozone concentrations in a tall contactor was made at various influent aqueous pHʹs and scavenger concentrations using an experimental contactor fabricated for this purpose. Comparison of the simulated and experimentally obtained aqueous ozone profiles showed adequate agreement. However, the experimentally obtained effluent gaseous ozone concentrations were consistently lower than the corresponding simulated values by approximately 13%. This discrepancy is probably due to gas-phase ozone decomposition occurring inside the reactor and in the headspace above the reactor.