Adsorption of phenol and chlorophenols on Ca-montmorillonite in aqueous solutions
Adsorption of phenol, 2-chlorophenol, and 2,4-dichlorophenol on Ca-montmorillonite was studied with batch experiments at 25°C. The results from the experiments show that the amount of the adsorption of the phenolic compounds increases with chlorination, i.e., phenol <2-chlorophenol <2,4-dichlorophenol. This adsorption trend is due to the differences in the affinity of the phenolic compounds between the adsorbent and water, that is more affinity to water leads to less adsorption. The adsorption of phenol is unrecognizable, while 2,4-dichlorophenol is showing the highest adsorption density despite the repulsion between dissociated dichlorophenol anions and montmorillonite surface. Freundlich model fits moderately well to the adsorption isotherm of 2-chlorophenol and 2,4-dichlorophenol. The calculated model parameters aren=1.50, 0.49 and logk F =0.51, 1.09 for 2-chlorophenol and 2,4-dichlorophenol, respectively.
Key wordsadsorption Ca-montmorillonite chlorophenol phenol
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- ATSDR, 1998, Toxicological profile for phenol. U.S. Department of Health and Human Services CAS # 108-95-2, Public Health Service, Atlanta, GA.Google Scholar
- Adamson, A.W., 1982, Physical Chemistry of Surfaces, 4th ed., John Wiley & Sons, New York, 664 p.Google Scholar
- Gullick, R.W., Weber, W.J. and Gray, D.H., 1996, Organic contaminants transport through clay liners and slurry walls. In. Sahwney, B. (ed.), Organic Pollutants in the Environment. Vol. 8, CMS Workshop Lectures. The Clay Minerals Society, Boulder, Co., p. 96–136.Google Scholar
- Johnston, C.T., 1996, Sorption of organic compounds on clay minerals: A surface functional group approach. In: Sahwney, B. (ed.), Organic Pollutants in the Environment. Vol. 8, CMS Workshop Lectures. The Clay Minerals Society, Boulder, Co., p. 1–44.Google Scholar
- Parks, G.A., 1967, Surface chemistry of oxides in aqueous systems. In: Stumm, W. (ed.), Equilibrium Concepts in Aqueous Systems Advanced Chemistry Series 67, American Chemical Society, Washington, p. 121–160.Google Scholar
- Weast, R.C., ed., 1985, CRC handbook of Chemistry and physics, 66th ed. CRC Press, Boca Raton, Florida.Google Scholar
- Zhang, Z.Z., Low, P.F., Cushman, J.H. and Roth, C.B., 1990, Adsorption and heat of adsorption of organic compounds on montmorillonite from aqueous solutions. Soil Science Society of America Journal, 54, 59–66.Google Scholar