COMBINED ABSORPTION AND SELF-DECOMPOSITION OF OZONE IN AQUEOUS-SOLUTIONS WITH INTERFACIAL RESISTANCE

A theoretical analysis is performed employing the film model for the i sothermal absorption and self-decomposition of ozone in aqueous soluti ons with interfacial resistance, which is inversely proportional to th e interfacial mass transfer coefficient k(g). A closed-form solution h as been obtained. The effects of system parameters on the ozone mass t ransfer rate are examined. These parameters include the interfacial re sistance (1/k(g)),the acidic and basic self-decomposition reaction rat e parameters (M(m)(0.5), M(n)(0.5); M(m) = [2D(A)k(m)C(Ai)(m-1)/((m+1) ]/k(L)(0))(2), M(n) = (2D(A)k(n)C(Ai)(n-1)/(n+1))/k(L)(0))(2), the rea ction orders (m,n), the pH value of solution, and the liquid-phase mas s transfer coefficient (k(L)(0)). The results indicate that the reduct ion effect of the interfacial resistance on the absorption rate is mos t significant for the situation with the larger values of M(m) and M(n ) as well as with higher pH values. Also, for any particular finite va lue of k(L)(0)/k(g), the reduction effect encountered is greater for a gas liquid contactor with a lower k(L)(0). The reduction effect shoul d be avoided in order to maintain a higher mass transfer rate of ozone in aqueous solution. This analysis is of importance for the efficient use of ozone in water/wastewater treatment processes in the presence of interfacial resistance substances such as surface active agents. Fo r some known special cases (for example, cases with no interfacial res istance), the present solution reduces to the previous works of other investigators.