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

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 (Delta H-0) has been determined from the van't Hoff plot using equilibrium data at different temperatures.