APPLICATION OF POLANYI ADSORPTION POTENTIAL THEORY TO ADSORPTION FROM SOLUTION ON ACTIVATED CARBON

Liquid-phase adsorption isotherms at 25° on an activated carbon have been determined, over a wide range of concentrations, for the following systems: Sudan III (benzeneazo-p-benzeneazo-β-naphthol) in acetone, cyclohexane, carbon tetrachloride, benzene, and carbon disulfide, and Butter Yellow (p-dimethylaminoazobenzene) in methanol, acetonitrile, acetone, 2-propanol, cyclohexane, heptane, benzene, and carbon disulfide. Except for the high capacity range, most of the data can be fitted to a correlation curve determined for the same carbon from gas-phase adsorption measurements, as predicted by the Polanyi adsorption potential theory. The experimental link between liquid and gas-phase adsorption and the relative constancy of the solvent effect on adsorption (measured in appropriate units) appear to introduce a measure of predictability to at least some liquid-phase adsorption isotherms. Adsorption tends to be weakest in solvents of highest refractive index.