Discussion of the theoretical isotherms describing adsorption from multicomponent liquid mixtures on heterogeneous solids of quasi-Gaussian energy distribution

Discussion of two isotherm equations describing adsorption from the non-electrolyte solutions over the whole concentration region on the solids characterized by the quasi-Gaussian energy distribution is presented. Some physical and mathematical features of the isotherms are discussed and compared and the aspects of correct equation choice for a given adsorption system are considered. This theoretical discussion is illustrated by using the experimental data of adsorption from binary and ternary solutions on different solid surfaces.