title: Adsorption of chromium onto activated alumina: kinetics and thermodynamics studies.
abstract: In this study, the removal of chromium (VI) by adsorption on activated alumina was investigated and the results were fitted to Langmuir, Freundlich, Dubinin-Redushkevich, and Temkin adsorption models at various temperatures. The constants of each model were evaluated depending on temperature. Thermodynamic parameters for the adsorption system were determined at 10, 25 and 40 degrees C. (deltaH degrees = -21.18 kJ x mol(-1); deltaG degrees = -8.75 to -7.43 kJ x mol(-1) and deltaS degrees = -0.043 kJ x K(-1) x mol(-1)). The obtained values showed that chromium (VI) adsorption is a spontaneous and exothermic process. The kinetic process was evaluated by first-order, second-order and Elovich kinetic models.
authors.affiliation: U.R Traitement et Dessalement des Eaux, Faculté des Sciences de Tunis, 2092 Manar II - Tunisie. ikhlassmarzouk@gmail.com
authors.forename: Ikhlass
authors.initials: I
authors.lastname: Marzouk
authors.forename: Lassaad
authors.initials: L
authors.lastname: Dammak
authors.forename: Béchir
authors.initials: B
authors.lastname: Hamrouni
mesh_terms: D000327:Adsorption; D000537:Aluminum Oxide / Q000737:chemistry*; D002857:Chromium / Q000302:isolation & purification*; D007700:Kinetics; D008956:Models, Chemical; D013816:Thermodynamics; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
chemical_list: D014874:Water Pollutants, Chemical; D002857:Chromium; D000537:Aluminum Oxide