Journal of Hazardous Materials 167 (2009) 531–535
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Journal of Hazardous Materials
journal homepage: www.elsevier.com/locate/jhazmat
Studies on the adsorption behavior of trace amounts of
90
Sr
2+
,
140
La
3+
,
60
Co
2+
,
Ni
2+
and Zr
4+
cations on synthesized inorganic ion exchangers
A. Nilchi
a,∗
, M.R. Hadjmohammadi
b
, S. Rasouli Garmarodi
b
, R. Saberi
c
a
Nuclear Science and Technology Research Institute, Nuclear Science Research School, J. I. H. Research Laboratories, P.O.Box 11365/8486, Tehran, Iran
b
Faculty of Chemistry, University of Mazandaran, Babolsar, Iran
c
Environment and Energy Faculty, Science and Research Branch, Islamic Azad University, Tehran, Iran
article info
Article history:
Received 29 April 2008
Received in revised form 8 December 2008
Accepted 8 January 2009
Available online 16 January 2009
Keywords:
Cation exchanger
Potassium zinc hexacyanoferrate(II)
Magnesium oxide–polyacrylonitrile
composite
Ammonium molybdophosphate
Adsorption behavior
abstract
Three inorganic ion exchangers namely potassium zinc hexacyanoferrate(II) (PZF), magnesium
oxide–polyacrylonitrile composite (MgO–PAN) and ammonium molybdophosphate (AMP) were syn-
thesized. The physicochemical properties of these ion exchangers were determined using different
techniques including inductively coupled plasma (ICP), CHNSO elemental analysis, infrared spectroscopy
(IR), X-ray diffraction (XRD), thermogravimetric (TGA) and pH – titration curve analysis. The solubility
of the synthesized ion exchangers in different acidic and alkaline media, their thermal stability and the
effect of gamma irradiation were investigated. It was observed that the exchange capacity of the ion
exchangers depend upon the pH value of the solution used. Furthermore, the adsorption of
90
Sr
2+
,
140
La
3+
,
60
Co
2+
and the distribution coefficient of these ion exchangers for Ni
2+
and Zr
4+
were studied. The effect
of parameters such as pH and contact time on the adsorption was also investigated and the optimum
conditions for separation of these ions were determined.
© 2009 Elsevier B.V. All rights reserved.
1. Introduction
A rapid development in nuclear energy, hydrometallurgy and
recovery of materials from industrial wastes has enforced attempts
to synthesize highly selective ion exchange materials [1–4]. The
ability of ion exchangers to remove trace ions from solution and the
concentration which may be achieved on elution with suitable solu-
tions have been used in the treatment of wastes and in processes
for recovery of metals from very dilute solutions. Ion exchang-
ers have been used extensively in treating rinse water wastes in
plating industry for example, where valuable metals are recovered
at costs comparable to or less than conventional chemical treat-
ment, with appreciable saving in space for treatment plant. Also, a
large number of ion exchangers such as zeolites, sodium titanates,
titanosilicates, hexacyanoferrates, acidic salts of multivalent metal,
salt of heteropolyacids and hydrous oxides have been investigated
for removal of fission products (
137
Cs,
90
Sr) and activation corro-
sion products such as
60
Co,
63
Ni,
65
Zn,
51
Cr,
54
Mn,
59
Fe and
95
Zr
from nuclear waste [5–16]. The major attraction in the use of inor-
ganic ion exchangers in such applications compared with synthetic
organic ones is their high thermal and radiation stabilities and com-
patibility with matrices used for their immobilization. In this work,
∗
Corresponding author. Tel.: +98 2188020273; fax: +98 2188021412.
E-mail addresses: anilchi@aeoi.org.ir, anooshn@hotmail.com (A. Nilchi).
the synthesis, characterization, ion exchange potential and ana-
lytical application of three inorganic ion exchangers for efficient
separation of
90
Sr
2+
,
140
La
3+
,
60
Co
2+
, Ni
2+
and Zr
4+
cations present
in nuclear wastes are examined.
2. Experimental
2.1. Reagents and apparatus
All the reagents and chemical used were of Analytical grade and
were obtained from Merck.
60
Co,
140
La and
90
Sr radionuclides were
supplied by Nuclear Science Research School of Iran.
The infrared spectra were recorded using a Brucker-Vector 22
spectrophotometer; X-ray powder diffractometry was carried out
using an 1800 PW Philips diffractometer with CuK beam in order
to determine the structure of the adsorbers. The finely powdered
sample of the adsorbers was packed in a flat aluminium sample
holder, where the X-ray source was a rotating anode operating at
40 kV and 30 mA with a copper target. Data were collected between
5
◦
and 70
◦
in 2; CHN analysis was performed using an Elementar-
Vario ELIII, CHNSO elemental analyzer, thermogravimetric analysis
were carried out using a DuPont model 951; the amount of Ni
2+
and
Zr
4+
were measured by a PerkinElmer inductively coupled plasma
(ICP) spectrometer model 5500; the concentration of Na
+
and Mg
2+
ions was determined by a PerkinElmer atomic adsorption spec-
trometer (AAS) model 843;the radioactivity was counted using an
0304-3894/$ – see front matter © 2009 Elsevier B.V. All rights reserved.
doi:10.1016/j.jhazmat.2009.01.028