Kinetics and Thermodynamics of Cr(VI), Cu(II), and Ni(II) Adsorption on Activated Carbon Prepared from Rice Hulls
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Date
2013
Journal Title
Journal ISSN
Volume Title
Publisher
Taylor & Francis Inc
Access Rights
info:eu-repo/semantics/closedAccess
Abstract
First, activated carbon was prepared by various ammonium compounds such as NH4NO3, NH4Cl, NH4Br, NH4I, NH4HCO3, and (NH4)(2)HPO4. The pore properties such as surface areas, pore volumes and pore sizes of them were compared under same activation conditions (600 degrees C, 5g of rice hull, 20g of ammonium compound, within a half-hour activation time). The highest surface area by Brunauer-Emmett-Teller (BET) method was obtained as 456.7667m(2)g(-1) by ammonium nitrate compared to other ammonium compounds, and then the kinetics and thermodynamics of Cr(VI), Cu(II), and Ni(II) ions removal from aqueous solutions on this activated carbon were studied. The adsorption data was found to follow second order kinetic model to explan the kinetics of Cr(VI), Cu(II), and Ni(II) ions adsorption, and rate constants were evaluated with the help of this kinetic model. Activation energy and other activation thermodynamic parameters (S, H, and G) were determined by means of the rate constants at different temperatures. Equilibrium data were fitted to the Langmuir and Freundlich adsorption isotherms. Freundlich isotherm best fits the experimental results. Thermodynamic parameters such as K-C, G, H, and S were also calculated. The positive value of S and negative values of G showed the spontaneous of this adsorption system, while the positive value of H pointed out this is an endothermic process.
Description
Keywords
Adsorption, Ammonium Nitrate, Kinetics, Rice Hull, Thermodynamics, Polyacrylamide-Grafted Sawdust, Chromium Iii Ion, Aqueous-Solution, Removal, Ash, Equilibrium, Copper
Journal or Series
Journal Of Dispersion Science And Technology
WoS Q Value
Q4
Scopus Q Value
Q3
Volume
34
Issue
9
