Mathematical model involving chemical reaction and mass transfer for the ozonation of dimethyl phthalate in water in a bubble column reactor

Abstract This research investigated the establishment of a mathematical model for the ozonation of dimethyl phthalate (DMP) through the analysis of the mass transfer and reactions in a semi-batch bubble column reactor. Negative step tracer experiments were conducted with ozone as a tracer, which indicated that the gas phase is perfectly well mixed at the gas flow rate of 400 mL/min. Based on the results from ozone absorption experiments the mass transfer coefficient of ozone was determined to be 0.0054 s−1. The measured stoichiometry ratio of the direct reaction between ozone and DMP was about 5. The calculated rate constant was 0.87 L/(mol·s) for the direct reaction between ozone and DMP. A mathematical model was established based on the component mass balance in the reaction system involving the direct and indirect reactions and mass transfer between gas and liquid phases enhanced by the chemical reactions. The model can predict the removal of DMP for the early stage of the ozonation process well. At the latter stage, the predicated removals deviated from the measured results mainly due to the consumption of ozone by side reactions.