Recovery of ammonia from waste or process water is significantly influenced by the presence of carbon dioxide. In order to achieve high recovery efficiency, a selective separation of carbon dioxide froth the liquid prior to the ammonia removal is often desired. In this article, a rigorous model is presented that is based on earlier works [E.Y. Kenig, R. Schneider, A. Gorak, Reactive absorption: optimal process design via optimal modelling. Chem. Eng. Sci. 56 (2001) 343-350: L. Kucka, I. Mueller. E.Y. Kenig, A. Gorak, On the modelling and simulation of sour gas absorption by aqueous amine solutions. Chem. Eng. Sci. 58 (2003) 3571-3578: B. Huepen, E.Y. Kenig, Rigorous modelling on NO, absorption in tray and packed columns, Chem. Eng. Sci. 60 (2005) 6462-6471.]. This model describes an integrated process for the selective removal of carbon dioxide comprising steam stripping, subsequent direct-contact condensation (DCC) of the stripping steam and absorption of undesired stripped ammonia in packed columns. Based on the film theory, the model directly considers heat and multicomponent mass transfer rates as well as chemical reaction kinetics. Diffusional interactions typical for multicomponent mass transfer can usually be neglected in absorption and stripping processes, but not necessarily in DCC of multicomponent vapour mixtures consisting of condensable and noncondensable components. Therefore. the rigorous model taking account of diffusional interactions via the Maxwell-Stefan equations is compared with the effective diffusivity method. It is shown that neglecting of molecular interactions may lead to poorly designed direct-contact condensers. The influence of the interactions in the tested system depends oil the mixture composition and it increases significantly when an additional component is added to the ternary mixture. (C) 2008 Elsevier B.V. All rights reserved.