Solute adsorption from dilute solutions on structurally heterogeneous solids

A new adsorption isotherm equation for describing solute adsorption from dilute solutions on structurally heterogeneous solids is applied. This equation is associated with a gamma-type distribution function, which characterizes the structural heterogeneity of a microporous solid. Parameters of this equation permit calculating the mean adsorption potential and the dispersion associated with the adsorption potential distribution. These two quantities characterize the energetic heterogeneity of a nonuniform microporous solid. The measured adsorption isotherms of phenol, p-nitrophenol, and p-chlorophenol from dilute aqueous solutions on two samples of activated carbon are used to examine the above-mentioned equation and to evaluate the adsorption parameters that characterize the structural heterogeneities of these samples.