Modeling cooperative adsorption of aromatic compounds in aqueous solutions to nonpolar adsorbent

Abstract

By a newly developed model according to the lateral interaction of adsorbate–adsorbate in the adsorbed phase in the description of the binary adsorption behaviors of phenol/aniline mixtures and 2-naphthalenesulfonic acid (NSA)/aniline mixtures in water on nonpolar adsorbent NDA100 at 293 and 313 K, respectively, cooperative adsorption was investigated and modelled. It is noteworthy that the experimental uptakes of adsorbates in the test binary-component systems are obviously larger than the corresponding ones predicted from Extended Langmuir model postulating no lateral interaction between the loaded molecules, which is assumably due to the cooperative effect mainly arisen from the acid–base interaction between the loaded aromatic acid (phenol, NSA) and aromatic base (aniline) molecules. The newly modified model, with single-component adsorption isotherm parameters and binary-component fitting parameters, generally showed a marked improvement in the correlation of binary adsorption equilibrium compared to the Extended Langmuir model, which used only single-component isotherm parameters.