文章基本信息

标题：Adsorption of a textile dye on synthesized calcium deficient hydroxyapatite (CDHAp): Kinetic and thermodynamic studies
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作者：El Boujaady H. ; Mourabet M. ; EL Rhilassi A. 等
期刊名称：Journal of Materials and Environmental Science
印刷版ISSN：2028-2508
出版年度：2016
卷号：7
期号：11
页码：4049-4063
出版社：University of Mohammed Premier Oujda
摘要：The adsorption of a reactive dye, Reactive Yellow 4 (RY4), from aqueous solution onto synthesized calcium deficient hydroxyapatite (CDHAp) was investigated. The adsorption kinetics was investigated using the parameters such as contact time, adsorbent quantity, initial dye concentration, initial pH, ionic strength, and solution temperature. The adsorbent has been characterized by pHzpc measurement, chemical analyses, FTIR, XRD and TEM. The kinetic study shows that equilibrium is quick. The kinetic data were best described by the pseudo second-order model (R2= 0.9999). The adsorption equilibrium was modeled by the Langmuir and Freundlich equations using linear and non-linear regression. The Langmuir model was found to be the best to describe the equilibrium isotherm data, with a maximum adsorption capacity of 51.08 mg.g -1 . In addition, the results showed that acid pH is favorable for the adsorption of dye, the introduction of Ca 2+ ions in the medium favors the adsorption and the maximum of adsorption decreases with increasing temperature from 298 to 318 K. Thermodynamic studies indicated that the dye adsorption process by calcium deficient hydroxyapatite (CDHAp) was physisorption, spontaneous and exothermic in nature. The results indicate that the adsorption is due to the electrostatic interaction between the sulphonic groups–SO 3- of dye and the PO 4 3- ,Ca 2+ and OH- groups in the surface of the Phosphate. Finally, Compared to adsorption experiments on other adsorbents, the results show that the calcium deficient hydroxyapatite (CDHAp) is an efficient adsorbent for Reactive Yellow dye.
关键词：Adsorption kinetics; CDHAp; Reactive dye; Equilibrium