Adsorption of polyethylene glycol (PEG) from aqueous solution onto hydrophobic zeolite

• Published in: Journal of colloid and interface science Vol. 260; no. 2; pp. 273 - 279
• Main Authors: Chang, C.Y., Tsai, W.T., Ing, C.H., Chang, C.F.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 15.04.2003; Elsevier
• Subjects: Chemistry; Exact sciences and technology; General and physical chemistry; Hydrophobic zeolite; Isotherm; Kinetic modeling; Liquid-phase adsorption; Polyethylene glycol; Restrictive diffusion; Solid-liquid interface; Surface physical chemistry; Isotherm; Hydrophobic zeolite; Kinetic modeling; Liquid-phase adsorption; Polyethylene glycol; Restrictive diffusion; Liquid solid adsorption; Adsorption isotherm; Adsorption capacity; Hydrophobic compound; Zeolite; isotherms; Experimental study; Molecular sieve; Ethylene oxide polymer; Kinetic model; Electrodeposition; Kinetic parameter; Aqueous solution; Diffusion coefficient
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/S0021-9797(02)00174-1

In the present study, a hydrophobic zeolite was used as an adsorbent for the adsorption of polyethylene glycol (PEG) in water solution and electroplating solution at 25 °C. The adsorption capacities were determined through the adsorption isotherms in a thermostated shaker. The rate of adsorption, on the other hand, was investigated in a batch adsorber under controlled process parameters such as initial PEG concentration (30, 70, 110, 150, 200, and 300 mg dm −3), agitation speed (200, 800, and 1000 rpm), and adsorbent particle size (0.72, 1.44, and 2.03 mm). A batch kinetic model, according to a pseudo-second-order mechanism, has been tested to predict the rate constant of adsorption, equilibrium adsorption capacity, time of half-adsorption, and equilibrium concentration by the fitting of the experimental data. The results of the adsorption isotherm and kinetic studies show that the adsorption process can well be described with the Langmuir and Freundlich models and the pseudo-second-order equation, respectively. Comparing the values of adsorption parameters of PEG in water solution and electroplating solution, there are no significant differences. In addition, the effective diffusion coefficient of the PEG molecule in the microporous adsorbent has been estimated at about 3.20×10 −8 cm 2 s −1 based on the restrictive diffusion model.