In this study, an oxidation model incorporating the mass transfer and kinetics approach based upon the rate constants for the reactions with ozone and center dot OH radicals was developed to predict the degradation of isopropyl alcohol (IPA) and formation of its main byproduct, acetone. The self-decomposition of ozone in buffered water at pH 3 and 7 occurred via a first-order reaction. The ozone mass transfer coefficients are considerably higher at pH 7 than pH 3 due to the participation in the chemical reaction toward the hydroxyl ion. The oxidation model considering side reactions: between ozone or center dot OH radicals and byproducts has been established using nonlinear simultaneous differential equations. The reaction coefficients for IPA degradation are 0.008, 0.0236, 1.4931, and 1.4909 s(-1) at pH 3 and 7 in 03 and O-3/UV processes, respectively. The larger reaction coefficient found in the ozone/UV system indicates several competing mechanisms for hydroxyl radicals.