Abdul Sattar Ali KHAN

Evaluation of thermodynamic parameters of cadmium adsorption on sand from Temkin adsorption isotherm

Thermodynamic parameters provide clues for finding the spontaneity of a given process at a given temperature. In the present work, the Temkin adsorption model was applied for evaluation of the thermodynamic parameters of cadmium adsorption studied on sand. The lateral interaction energy parameter was found to be unity, which showed that the heat of adsorption is directly proportional to the fraction of free adsorption sites. The values of D H° and D S° were --4.8 kJ mol-1 and 42 J mol-1 K-1, respectively. The value of D G° was negative, indicating the spontaneity of cadmium adsorption on sand.

Anahtar Kelimeler:

Thermodynamic parameters, spontaneity, Temkin adsorption model, cadmium, sand, modified isotherm

Evaluation of thermodynamic parameters of cadmium adsorption on sand from Temkin adsorption isotherm

Keywords:

Thermodynamic parameters, spontaneity, Temkin adsorption model, cadmium, sand, modified isotherm,

PDF

___

is directly proportional to the fraction of free adsorption sites. The values of Δ H ◦ and Δ S ◦ were –4.8 kJ ◦ and positive value of Δ S ◦ , respectively. The negative value of Δ H −1 K −1 and 42 J mol −1 mol result in a negative value of Δ G ◦ at any temperature, indicating the spontaneity of cadmium adsorption on sand. Langmuir, I. J. Am. Chem. Soc. 1918, 40, 1361-1403.
Freundlich, H.; Heller, W. J. Am. Chem. Soc. 1939, 61, 2228-2230.
Temkin, M. I. Zh. Fiz. Khim. 1941, 15, 296-332.
Brunauer, S.; Emmett, P. H; Teller, E. J. Am. Chem. Soc. 1938, 60, 309-319.
Dubinin, M. M.; Radushkevich, L. V. Dokl. Akad. Nauk. SSSR 1947, 55, 331-334.
Usmani, T. H.; Ahmed, T. W.; Motan, M. T.; Yousufzai, A. H. K. Jour. Chem. Soc. Pak. 1998, 20, 1-7.
Thompson, H. M.; Rayner, G. J.; Hill, S.; de Whalley, H. C. S. J. Appl. Chem. 1957, 7, 49-63.
Bansal, R. C.; Goyal, M. Activated Carbon Adsorption, CRC Press, Boca Raton, FL, 2005.
Inglezakis, V. J.; Poulopoulos, S. G. Adsorption, Ion Exchange and Catalysis: Design of Operation and Environ- mental Applications, Elsevier, Amsterdam, 2006.
Hasany, S. M.; Chaudhary, M. H. J. Radioanal. Nucl. Chem. 2001, 247, 335-340.
Okieimen, F. E.; Okundia, E. U.; Ogbeifun, D. E. J. Chem. Tech. Biotechnol. 1991, 51, 97-103.
Lee, S. H.; Yang, J. W. Separ. Sci. Tech. 1997, 32, 1371-1387.
Naiya, T. K.; Chowdhury, P.; Bhattacharya, A. K.; Das, S. K. Chem. Eng. J. 2009, 148, 68-79.