Ozonation is an effective treatment for removing various organic pollutants from aquatic systems. The Rct concept, which is defined as the ratio of OH exposure to O3 exposure, has been widely used to predict the removal efficiency of target compounds, but it has significant variations by water temperature and initial O3 dose which are crucial parameters in drinking water plant. The ROH,O3 concept, which is defined as the OH exposure by O3 consumption, was proposed as a kinetic parameter for characterization and kinetic modeling for ozonation. The ROH,O3 concept is independent of temperature and initial O3 dose. A higher ROH,O3 value indicates a higher OH formation when the same amount of O3 is consumed in different water samples; therefore, the OH yield from O3 decomposition of the water samples can be compared using the ROH,O3 values. The ROH,O3 concept can also be used to characterize and model the initial ozone demand phase, and it is more convenient method compared to Rct concept. Using the ROH,O3 concept, the dynamic O3 and OH kinetics and the removal efficiencies of iopromide and ibuprofen were well predicted (R2 = 0.98) over a wide range of experimental conditions (n = 124).
Keywords: Advanced oxidation process; Hydroxyl radical; Kinetics; Ozone; R(OH,O3); R(ct).
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