Absorption of ozone in aqueous solutions with self‐decomposition effect

Abstract

A theoretic analysis employing the film model for the isothermal absorption of ozone in aqueous solutions with self‐decomposition of general orders (not necessarily integers) is performed. A closed‐form solution has been obtained. The effects of system parameters on the ozone mass transfer rate are examined. These parameters include the self‐decomposition reaction rate parameters (M_m ⁰⁵, M_n ⁰⁵), the reaction orders (m, n), the pH value of solution, and the liquid‐phase mass transfer coefficient (k_L°). The results indicate that M_m and M_n significantly enhance the absorption rate of ozone. In favor of the direct use of molecular ozone, either the liquid phase should be maintained in the neutral or acidic conditions, or the gas‐liquid contactors operated with higher values of k_L° if the liquid phase is in the strong basic conditions. The reverse choices, on the other hand, would favor the formation of self‐decomposition specices of ozone such as free radicals. This analysis is of importance for the efficient use of ozone in the water/wastewater treatment processes. For some known special cases (for example, M_m=O for any n), the present solution reduces to the previous works of other investigators.