Uptake of heavy metal ions from aqueous solutions by sorbents
obtained from the spent ion exchange resins
D. Kołodynska a, *
, J. Krukowska-Ba˛k a
, J. Kazmierczak-Razna b
, R. Pietrzak b
a
Department of Inorganic Chemistry, Faculty of Chemistry, Maria Curie-Skłodowska University, M. Curie Skłodowska Sq. 2, 20-031 Lublin, Poland
b
Adam Mickiewicz University in Poznan, Faculty of Chemistry, Umultowska 89b, 61-614 Poznan, Poland
a r t i c l e i n f o
Article history:
Received 3 January 2017
Received in revised form
4 February 2017
Accepted 13 February 2017
Available online 16 February 2017
Keywords:
Spent ion exchange resin
Pyrolysis
Sorption
Heavy metal ions
Utilization
a b s t r a c t
Obtaining useful sorbents from spent materials is of great importance. The paper presents the results of
tests determining the kinetic and adsorption parameters on the removal of heavy metal Cu(II), Cd(II),
Co(II) and Pb(II) ions on the carbonaceous adsorbents W1 KPS, W2 KPS, D1 CC3 and D2 CC3 obtained
from spent ion exchangers. Among others the sorption effects of contact time, initial concentration,
solution pH, influence of interfering ions were studied. W1 KPS obtained by the microwave heating
exhibits a higher affinity for heavy metal ions than W2 KPS. However, for the sorbent obtained in the
resistance furnace higher values of the sorption capacity were obtained for D2 CC3 rather than D1 CC3. It
was found that the sorption capacity increases with the increasing initial concentration of the solution
and phase contact time. The maximum pH adsorption was found at pH 5.0. A better fit of the kinetic data
from the experimental one was presented using the pseudo second order model. In this paper,
desorption using acidic desorbing agents was also examined. The results show that 2 M HNO3 is the most
effective desorbing agent. Carbonaceous sorbents were characterized using elemental analysis, Fourier
transform infrared spectroscopy and point of zero charge measurements. Differential scanning calo-
rimetry analysis was also conducted.
© 2017 Elsevier Inc. All rights reserved.
1. Introduction
Ion exchange resins are water insoluble solids containing
cationic and anionic groups capable of ion exchange with other ions
from the solution [1]. Ion exchange resins are widely used in many
processes such as: nitrate removal from drinking water, water
treatment in nuclear power plants, separation of chemicals, water
softening and metal separation in iron and steel industry [2e8].
Spent ion exchange resins are flammable and toxic wastes. There-
fore their treatment is of significant importance in reduction of
potential hazard to the human health and environments [9].
Several techniques are used for the treatment and disposal of spent
resins like cementation, bitumization and oxidation processes
including combustion as well as Fenton oxidation process and py-
rolysis [4,10e12].
Pyrolysis reduces the volume of wastes while retaining a stable
final product. In this process there were distinguished three steps:
(i) water evaporation; (ii) functional group decomposition and (iii)
base polymer combustion. It involves thermal decomposition in the
temperature range 773e973 K in an inert atmosphere which leads
to obtaining solid products with a high molecular weight as well as
gas products [13e17]. Low temperature pyrolysis experiments in
Canada, Japan, Germany and Sweden in the 80's of the last century
demonstrated the potential of this process especially in the case of
spent ion exchangers from the radioactive plants. It was found that
40% of cation exchangers and 60% of anion exchangers in the
temperature range 363e493 K loss of weight associated with the
evaporation of water was observed [18]. The next stage in the
temperature range 553e713 K was related to the breakdown of
functional groups of ion exchange resins. The third range of weight
loss was in the range 773e1233 K for cationic resins and
773e1053 K for anionic resins. This is associated with exchangers
combustion. It has been shown that at 873 K the degradation extent
reaches 62% for cation exchangers and 87% for anion exchangers. At
1073 K no gaseous products formed. It was also found that anionic
resins are degraded faster and cationic ones more slowly because
they are more stable [13,19]. Therefore the pyrolysis process de-
pends on the type of ion exchangers and their degree of cross-
linking. Choosing such factors as: pyrolysis atmosphere,* Corresponding author.
E-mail address:
[email protected] (D. Kołodynska).
Contents lists available at ScienceDirect
Microporous and Mesoporous Materials
journal homepage: www.elsevier.com/locate/micromeso
http://dx.doi.org/10.1016/j.micromeso.2017.02.040
1387-1811/© 2017 Elsevier Inc. All rights reserved.
Microporous and Mesoporous Materials 244 (2017) 127e136
carbonization temperature, heating rate and process conditions
(aerobic, anaerobic) microporous carbonaceous materials can be
prepared [20]. The advantages of pyrolysis are...
