Solubility, Self-decomposition and Mass Transfer Characteristics of Ozone in Aqueous Solution

Abstract

The effects of temperature and pH on solubility, self-decomposition reaction and mass transfer were studied to grasp the characteristics of ozone in aqueous solution from the viewpoint of water treatment. Regardless of flow rate, the linear relationship existed between concentration of ozone in the feed gas and equilibrium concentration of ozone in aqueous solution, and its proportionality constant (apparent distribution coefficient m) decreased with increase of both temperature and pH. The experimental date on the self-decomposition of ozone was most satisfactorily explained if the reaction was assumed to be of the first order, so that decomposition rate constant (k) increased remarkably with increase of both temperature and pH. The overall mass transfer coefficient (K_L) was affected by the flow rate as well as temperature and pH, and it decreased with increasing flow rate by the interaction of bubbles, increasing with increase of temperature and decrease of pH. The real distribution coefficient (m*) and Henry's constant (E) can be calculated from the apparent distribution coefficient by taking account of the self-decomposition of ozone, so that they become _??_where, a is constant area per unit volume of column, and X is a constant. The values calculated from the equations above satisfactorily agreed with the values previously reported.