The theory of formation of surface complexes and its application to the description of multicomponent dynamic sorption systems

The fundamentals of the theory of formation of surface complexes (or the surface complexation theory, SCT), which is used in processing the results of studies on the equilibria in multicomponent ion exchange sorption systems, are outlined. The advantage of the theory is the use of the sorption characteristics of binary ion exchange systems for the description and calculation of multicomponent equilibria with allowance for the medium pH value. The solutions to some problems of nonlinear sorption dynamics theory obtained using the description of multicomponent equilibria in the framework of the SCT model are considered. Experimental data on the concentration distributions of components in frontal and displacement chromatograms are compared with the results of corresponding numerical calculations using various sets of parameters of the SCT model (including versions with allowance for the effect of complexation reactions in the mobile phase).