Removal of chloride ion from aqueous solution by ZnAl-NO(3) layered double hydroxides as anion-exchanger.
The layered double hydroxides (LDHs) containing nitrate as the interlayer anion has a high anion-exchange capacity in the presence of appropriate anions. In the light of this, ZnAl-NO(3) LDHs have been employed to remove chloride ion from aqueous solution in a batch mode. The influences of conditions for chloride ion uptake, including dosage of LDHs, pH of aqueous solution, and temperature on anion-exchange have been investigated, respectively. The thermodynamic parameters including Gibbs free energy (DeltaG(0)), standard enthalpy change (DeltaH(0)), and standard entropy change (DeltaS(0)) for the process were calculated using the Langmuir constants. It was found from kinetics test that the pseudo-second order kinetics model could be used to well describe the uptake process. An E(a) value of 10.27 kJ/mol provides evidence the anion-exchange process. The explanation of anion-exchange phenomenon has also been supported by X-ray diffraction and FT-IR spectra.
West Branch of Zhejiang University of Technology, Zhejiang 324000, China. lianglv_qzxy@126.com
Liang
L
Lv
Peide
P
Sun
Zhengyu
Z
Gu
Hangeng
H
Du
Xiangjun
X
Pang
Xiaohong
X
Tao
Rufeng
R
Xu
Lili
L
Xu
D000537:Aluminum Oxide / Q000737:chemistry*; D000837:Anion Exchange Resins; D002712:Chlorides / Q000737:chemistry*; D002852:Chromatography, Ion Exchange / Q000379:methods; D004305:Dose-Response Relationship, Drug; D006863:Hydrogen-Ion Concentration; D006878:Hydroxides / Q000737:chemistry*; D007477:Ions; D007700:Kinetics; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D013816:Thermodynamics; D013997:Time Factors; D014961:X-Ray Diffraction; D015032:Zinc / Q000737:chemistry*
D000837:Anion Exchange Resins; D002712:Chlorides; D006878:Hydroxides; D007477:Ions; D015032:Zinc; D000537:Aluminum Oxide