ISSN 1070-4272, Russian Journal of Applied Chemistry, 2007, Vol. 80, No. 11, pp. 1836 !1840. + Pleiades Publishing, Ltd., 2007.
Original Russian Text + O.P. Zykova, T.A. Khodakovskaya, E.Ya. Markiv, V.S. Aleksandrova, S.A. Kirillov, 2007, published in Zhurnal Prikladnoi Khimii,
2007, Vol. 80, No. 11, pp. 1811!1814.
OF SYSTEMS AND PROCESSES
Sorption of Phosphate and Arsenate Ions from Solutions
by Sorbents of the System TiO
O. P. Zykova, T. A. Khodakovskaya, E. Ya. Markiv,
V. S. Aleksandrova, and S. A. Kirillov
Institute of Sorption and Endoecology, National Academy of Sciences of Ukraine, Kiev, Ukraine
Received November 21, 2006; in final form, April 2007
Abstract-Hydrated nanosize oxides of the system TiO
O were tested as sorbents for
recovery of phosphate and arsenate ions from aqueous solutions in a wide range of pH values. The optimal
compositions of the sorbents were found, their ion-exchange functions were studied, and limiting sorption
capacities were determined.
Recently, researchers’ attention has been focused
on a search for efficient, nontoxic, and inexpensive
sorbents for water treatment to remove phosphorus
and arsenic . These include hydrated oxides of
Group II3IV metals having high affinity for phos-
phates, arsenates, and arsenites. In particular, the fol-
lowing sorption activity series have been established
. Moreover, it has been noted
that the sorption of arsenates by soils correlates with
their content of aluminum and iron oxides .
Because hydrated aluminum, iron, and titanium
oxides are the most promising as absorbents of phos-
phates and arsenic, the sorption properties of their
natural and synthetic varieties have been extensively
studied [2, 4311]. These substances retain high selec-
tivity at low concentrations of the elements being
absorbed (0.33300 mg l
) and high concentrations of
the salt background. They show an ion-exchange func-
tion toward phosphates, arsenates, and arsenites.
Therefore, they can be repeatedly used, which makes
them attractive for treatment of not only wastewater,
but also drinking and mineral water.
An efficient method for control over the sorption-
selective properties of inorganic ion exchangers is
synthesis of mixed or modified sorbents [12, 13].
In addition, the cost of the thus obtained ion ex-
changers can be lowered by using intermediates and
process waste from chemical and metallurgical in-
dustries as raw materials.
The aim of this study was to examine the sorption
characteristics of new composite materials of the com-
from a titanyl sulfate solution produced in the process
cycle of breakdown of the ilmenite concentrate at
Sumykhimprom Open Joint-Stock Company.
A 3.184 M process solution of TiOSO
and sulfate ion concentrations of 0.57 and 5.79 M,
respectively, served as a titanium-containing raw ma-
terial for synthesis of sorbents. The solution was
diluted with water to a titanium concentration of
1 M and, when necessary, enriched with aluminum
chloride. To this solution we added with vigorous
stirring an equivalent, for complete precipitation of
hydroxides, amount of a 3 M NH
OH solution. The
resulting gel was poured onto a filter paper and dried
in air at room temperature to complete solidification.
Further, it was washed for a long time with distilled
water to remove sulfates, chlorides, and ammonium
ions, with the presence of SO
ions in the
filtrates monitored using qualitative reactions with
barium and silver ions. Then it was dried in air at
room temperature, ground, and sieved to select the
0.253 0.5-mm fraction.
The ion-exchange capacity and chemical resistance
of the sorbents, as well as the sorption of phosphate
and arsenate ions, were studied by the static method.
To 20 ml of a solution we added 200 mg of a sorbent,