Russian Journal of Applied Chemistry, 2012, Vol. 85, No. 4, pp. 684−685.
Pleiades Publishing, Ltd., 2012.
Original Russian Text © M.Kh. Annagiev, Dzh.T. Rustamova, S.S. Bairamova, 2012, published in Zhurnal Prikladnoi Khimii, 2012, Vol. 85, No. 4, pp. 679−680.
Study of Phenol Adsorption on Modiﬁ ed Forms of Zeolite
M. Kh. Annagiev, Dzh. T. Rustamova, and S. S. Bairamova
Nagiev Institute of Chemical Problems, National Academy of Sciences of Azerbaijan, Baku, Azerbaijan
Received May 18, 2010
Abstract—Analcime samples were studied with the aim of cleaning air from phenol.
Inexhaustible reserves of zeolites, which are among
the most promising natural aluminosilicates, are abundant
in Azerbaijan Republic. Development of a procedure for
the preparation of new effective sorbents based on natural
zeolites is of a great practical importance for reﬁ ning and
drying industrial gases and liquid hydrocarbons and for
environment protection against various toxic substances.
The publications [1–4] are devoted to the preparation
of adsorbents and catalysts by treating natural zeolites
with aqueous solutions of salts of various metals and
acids, and also to the study of their physicochemical prop-
erties by means of modern physical methods of analysis.
The aim of the present work was to study adsorption
properties of natural and modiﬁ ed forms of zeolites.
Natural zeolites of the Lenkoran deposit of Azerbaijan
Republic were chosen as a subject of the study.
The mineral composition of analcime samples was
determined by the roentgenography and thermal analysis
methods [1, 5], and it was found that they contain 80–85%
of zeolite, remaining minerals being quartz, calcite, and
Zeolite was subjected to the 6-fold treatment within
6 h by aqueous solutions of sulfuric acid of various con-
centration at 368 K and the weight ratio zeolite : solu-
tion = 1 : 10, and on this basis sorbents were obtained.
Washed out, ﬁ ltered, and dried up sorbents were subjected
to physicochemical studies. The thermoanalytic study was
carried out on a МОМ (Hungary) derivatograph under
the following conditions: heating rate of 10 degree·min
weighted sample of 0.7 g; sensitivity of a galvanometer
in the differential thermal analysis (DTA) was 1/5 and in
the differential thermal gravimetric analysis (DTG), 1/3;
the measurement standard was Аl
; air medium. The
X-ray study was carried out on a DRON-2.0 apparatus.
The nature, force, and amount of the basic centers on
the surface of samples were studied by the adsorption of
molecular probes. The procedure of the determination is
described in detail in [2, 3, 6–9].
One endothermic effect with a maximum at 393 K
corresponding to the phenol desorption from a sample
surface is observed in the DTA curves of natural analcime
with adsorbed phenol molecules [7–9].
After treatment of analcime with 1 N aqueous solu-
tion of sulfuric acid and adsorption of phenol molecules
on it, the effects with maxima at 393 K in the DTA and
DTG curves are displaced up to 423 K. Simultaneously
the adsorption capacity of the sorbent with respect to
phenol molecules increases.
After treatment of natural analcime with 2 N aque-
ous solution of sulfuric acid and adsorption of phenol
molecules on it, intensity of the endothermic effect in the
DTA and DTG curves with the maxima at 433 K increases
and an additional endothermic effect with a maximum at
733 K appears, which points to the appearance of a strong
basic centre on the sample surface.
When a sample of analcime with phenol is heated after
treatment with a 4 N aqueous solution of sulfuric acid,
intensive endothermic effects with maxima at 453 and
733 K are observed in the DTA curve. After treatment of