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Removal of cadmium(II) ions from aqueous solution using Ni (15 wt.%)-doped α-Fe2O3 nanocrystals: equilibrium, thermodynamic, and kinetic studies.

Authors :
OuldM'hamed, Mohamed
Khezami, L.
Alshammari, Abdulrahman G.
Ould-Mame, S. M.
Ghiloufi, I.
Lemine, O. M.
Source :
Water Science & Technology. 2015, Vol. 72 Issue 4, p608-615. 8p.
Publication Year :
2015

Abstract

The present publication investigates the performance of nanocrystalline Ni (15 wt.%)-doped α-Fe2O3 as an effective nanomaterial for the removal of Cd(II) ions from aqueous solutions. The nanocrystalline Ni-doped α-Fe2O3 powders were prepared by mechanical alloying, and characterized by X-ray diffraction and a vibrating sample magnetometer. Batch-mode experiments were realized to determine the adsorption equilibrium, kinetics, and thermodynamic parameters of toxic heavy metal ions by Ni (15 wt.%)-doped α-Fe2O3. The adsorption isotherms data were found to be in good agreement with the Langmuir model. The adsorption capacity of Cd(II) ion reached a maximum value of about 90.91 mg g-1 at 328 K and pH 7. The adsorption process kinetics was found to comply with pseudo-second-order rate law. Thermodynamic parameters related to the adsorption reaction, free energy change, enthalpy change and entropy change, were evaluated. The found values of free energy and enthalpy revealed a spontaneous endothermic adsorption-process. Moreover, the positive entropy suggests an increase of randomness during the process of heavy metal removal at the adsorbent--solution interface. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
02731223
Volume :
72
Issue :
4
Database :
Academic Search Index
Journal :
Water Science & Technology
Publication Type :
Academic Journal
Accession number :
108774618
Full Text :
https://doi.org/10.2166/wst.2015.245