Adsorption of Dilute Alcohols onto Cyclodextrin–Polysulfone Membrane: Experimental and Theoretical Analysis

The adsorptive separation of dilute alcohols onto polymeric membrane has been investigated in this work. The adsorption experiments have been performed in a stirred reactor using an indigenously developed membrane. Equilibrium adsorption isotherms and kinetics have also been investigated. The kinetic data experimentally obtained at different concentrations have been analyzed using pseudo-first-order, pseudo-second-order, and an intraparticle diffusion models. The experimental data satisfied the pseudo-second-order model well. Adsorption isotherms have been interpreted from Langmuir, Freundlich, and Temkin isotherms, and Langmuir isotherm exhibited a better fit to the experimental data. It has been observed that the adsorption depends on the different interactions occurring at the solid–liquid interface, i.e., hydrophobic, dipole–dipole, and hydrogen bonding which are interpreted by considering interaction energy between adsorbent and adsorbate using density functional theory and MP2. Physical properties of the adsorbent and quantitative structure–activity relationship properties of the adsorbate play an important role in the equilibrium of adsorption. The experimental value of heat of adsorption (Δ H 0 ) has been determined from the van’t Hoff plot using equilibrium data at different temperatures.