Kinetics of Ozone Decomposition: A Dynamic Approach

Abstract

Decomposition kinetics of ozone in aqueous solution were studied at 20 °C and in the pH range 2–10, under both quiescent and dynamic conditions. The data obtained in a batch reactor under quiescent conditions were analyzed by integral, initial-rate, and differential methods. The results indicated that ozone decomposes by a second-order reaction with respect to ozone concentration. The second-order decomposition kinetics determined in the batch reactor was confirmed by using a mathematical model developed for ozone decomposition in an ozone contact column and the experimental observations under such dynamic conditions. The rate of decomposition was found to be relatively insensitive to pH below 4 and relatively slow under such acidic conditions (kd = 0.27 L/(mols)). Above pH 4, the rate is pH dependent with kd = k0[OH−]0.55, where k0 is specific to the chemical composition of the aqueous system. © 1982, American Chemical Society. All rights reserved.