LIQUID-PHASE MASS-TRANSFER IN MULTICOMPONENT ION-EXCHANGE .2. SYSTEMSWITH IRREVERSIBLE CHEMICAL-REACTIONS IN THE FILM

Liquid-phase mass transfer in ion exchange controlled by diffusion acr oss a Nernst film was studied. The expression for the momentary ion fl uxes in systems without chemical reactions which was derived in a prev ious article is expanded to the more general case of systems where an irreversible chemical reaction occurs inside the film. In the case of two counterions and two colons an analytical solution is obtained, whi ch for the first time allows arbitrary valences to be adopted for all ions. For the general case of any number of counterions and colons the original system of differential equations is reduced to a set of nonl inear, algebraic equations, which are much easier to solve. Exemplary calculations show that the introduction of an irreversible chemical re action does not necessarily increase the effective diffusion coefficie nts of the ions and that in systems with chemical reactions in the fil m the total concentration at the resin boundary may substantially diff er from that in the bulk, even for small fractions of the reacting col ons.