Modeling of 2-phenylethanol adsorption onto polymeric resin from aqueous solution: Intraparticle diffusion evaluation and dynamic fixed bed adsorption

Abstract

Adsorption of 2-phenylethanol from an aqueous solution onto hyper-crossed-linked adsorption resin Macronet MN270 was investigated in a fixed bed column. Adsorption equilibrium was obtained in batch experiments and the results were fitted with the Langmuir isotherm model. A batch adsorption experiment was performed to determine the intraparticle diffusion mechanism. It was found that pore volume diffusion cannot solely govern the intraparticle mass transfer. According to the results of the batch experiment, surface diffusion plays an important role in the adsorption of 2-phenylethanol. Diffusion coefficients obtained in the batch experiment were further verified by comparison of the experimental data with the results of the mathematical model of fixed bed adsorption which was able to predict experimental breakthrough curves obtained under various conditions. A better description of the experimental data was obtained using the mathematical model which considered pore volume diffusion together with surface diffusion. The varying parameters in the measurements of breakthrough curves were: particle diameter, column diameter, volumetric flow rate and the inlet column concentration. Fixed bed adsorption experiments showed that smaller particles together with lower volumetric flow rate produce sharper breakthrough curves. The effect of external mass transfer and axial dispersion was not very significant. Lastly, fixed bed desorption of 2-phenylethanol with water was tested and was shown to be ineffective. Therefore, different solvents for 2-phenylethanol desorption were recommended.