1070-4272/03/7609-1414$25.00C2003 MAIK [Nauka/Interperiodica]
Russian Journal of Applied Chemistry, Vol. 76, No. 9, 2003, pp. 1414 !1417. Translated from Zhurnal Prikladnoi Khimii, Vol. 76, No. 9,
2003, pp. 1454!1457.
Original Russian Text Copyright + 2003 by Evtyukhov, Berezyuk.
AND ION-EXCHANGE PROCESSES
Sorption Properties of Natural Aluminosilicates
(Clay, Loam, Sandy Loam, Zeolite)
S. A. Evtyukhov and V. G. Berezyuk
Ural State Technical University, Yekaterinburg, Russia
Received May 22, 2002
Abstract-Sorption of Ni
, and Cr
from model solutions with natural sorbents (clay,
loam, sandy loam, zeolite) was studied. The optimal conditions of sorption were determined. The effect of pH
and electrolytes on the sorption efficiency was studied.
A study of sorption properties of natural materials
was performed with soil samples (clay, loam, sandy
loam, zeolite) collected near Nizhni Tagil and Revda
towns (Sverdlovsk oblast) in which the environmental
situation is presently very bad. As zeolite sample we
took clinoptilolite of the Kholinsk deposit (Buryatia).
The compositions of aluminosilicates studied were as
, wt %): clinoptilolite 65.7
and 11.5; clay 70.1 and 18.2; loam 65.8 and 24.3; and
sandy loam 86.8 and 5.6, respectively. Estimation
of the sorption power of soils would allow prediction
of the danger of groundwater pollution with metals
from sewage percolating through soils and monitoring
of the features of sorption processes in such tech-
nologies as underground and heap leaching [1, 2].
Sorption was studied under static conditions by the
method of separate samples. A sorbent sample (m
was immersed in 100 ml of a model solution with
a known metal concentration, and the mixture was
agitated with a shaker. The time in which the sorption
equilibrium was attained was determined in pre-
liminary experiments. As a rule, the time of contact of
the sorbent and solution was no more than 30 min.
The required pH was adjusted with 1 N H
0.1 N NaOH. The completeness of metal recovery was
monitored by the standard methods . Sorption of
metal ions was performed with both nonfractionated
and fractionated zeolite. The 0.531.5-mm fraction
proved to be optimal.
To choose metal ions that make the major contribu-
tion to the groundwater pollution in the region in
question, we collected information on the quantitative
and qualitative composition of sewage from industrial
plants. The typical pollutants are copper, nickel, man-
ganese, and iron compounds, bichromates, sulfates,
and oil products. A study of leaching of clay, loam,
and sandy loam in various media showed that the
main metal pollutants of the groundwater are Ni
, and Cr
. In our experiments, we used
, and Al
The sorption efficiency was estimated by the proc-
ess time t and degree of metal recovery from the solu-
tion S (%):
are the initial and equilibrium
metal concentration, respectively, mg l
The data were treated by standard methods .
The sorption efficiency substantially depends on
pH. The effect of pH was studied within the pH range
0.738.5. The results are shown in Figs. 1 and 2. In
acidic media (pH < 3.033.5), the recovery of all the
metals studied decreases because of the competitive
effect of the acid. At pH > 4.034.5, hydrolyzed metal
species are formed, which are well sorbed with the
sorbent (the recovery with zeolite reaches 98399.5%
and with soils, 65385%).
Sorption of Ni(II) reaches 98% (pH > 4.0); that of
Cu(II), 99.5% (pH > 5.5); and that of Fe(III), 75%
(pH ~ 3.0) and more than 90% (pH > 7.5).
Chromium can exist in solution as Cr
medium), as hydroxo complexes, or as chromate or
bichromate ions ; its behavior is rather complex. In
neutral and weakly alkaline media, Cr
to chromium(III) hydroxide. The recovery of Cr
amounts to 96397% at pH > 2.9.
The recovery of Mn is affected by the features of
conversion of manganese compounds into MnO