A predictive model for design of fixed-bed adsorbers for treatment of multicomponent waters and wastewaters is developed and compared to data from experimental systems. The model incorporates both liquid and solid phase resistances to mass transfer. The partial differential equations resulting from conceptual analysis of the model are solved numerically and the numeric algorithm is presented. Two bisolute systems, selected on the basis of providing a severe test of generality, are used for model verification. The components of one system exhibit substantially different affinities for adsorption as well as different intraparticle diffusion characteristics, while those of the second exhibit different adsorption affinities but similar microtransport characteristics. Satisfactory agreement is found between model predictions and experimental data under these rather broad conditions.