Adsorption of Zinc(II) on diatomite and manganese-oxide-modified diatomite: A kinetic and equilibrium study
JOURNAL OF HAZARDOUS MATERIALS, vol.193, pp.27-36, 2011 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 193
- Publication Date: 2011
- Doi Number: 10.1016/j.jhazmat.2011.06.058
- Journal Name: JOURNAL OF HAZARDOUS MATERIALS
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Page Numbers: pp.27-36
- Keywords: Diatomite, Adsorption, Zinc, Manganese oxides, Kinetic, AQUEOUS-SOLUTION, NATURAL DIATOMITE, SURFACE-CHEMISTRY, METHYLENE-BLUE, HEAVY-METALS, REMOVAL, SORPTION, IONS, KAOLINITE, ZN(II)
- Open Archive Collection: AVESIS Open Access Collection
- Van Yüzüncü Yıl University Affiliated: Yes
Abstract
The removal of Zn(II) ions from aqueous solution was studied using natural and MnO2 modified diatomite samples at different temperatures. The linear Langmuir, Freundlich and Dubinin-Radushkevich (D-R) adsorption equations were applied to describe the equilibrium isotherms. From the D-R model, the mean adsorption energy was calculated as >8 kJ mol(-1), indicating that the adsorption of Zn(II) onto diatomite and Mn-diatomite was physically carried out. In addition, the pseudo-first-order, pseudo-second-order and intraparticle diffusion models were used to determine the kinetic data. The experimental data were well fitted by the pseudo-second-order kinetic model. Thermodynamic parameters such as the enthalpy (Delta H-0), Gibbs' free energy (Delta G(0)) and entropy (Delta S-0) were calculated for natural and MnO2 modified diatomite. These values showed that the adsorption of Zn(II) ions onto diatomite samples was controlled by a physical mechanism and occurred spontaneously. (C) 2011 Elsevier B.V. All rights reserved.