Russian Journal of Applied Chemistry, 2011, Vol. 84, No. 10, pp. 1721−1725.
Pleiades Publishing, Ltd., 2011.
Original Russian Text © E.A. Strel’tsova, I.V. Puzyreva, O.V. Volyuvach, 2011, published in Zhurnal Prikladnoi Khimii, 2011, Vol. 84, No. 10, pp. 1630−1634.
OF SYSTEMS AND PROCESSES
Adsorption of Alkylammonium Chlorides by Freshly
Precipitated Aluminum and Iron(III) Hydroxides
E. A. Strel’tsova, I. V. Puzyreva, and O. V. Volyuvach
Mechnikov National University, Odessa, Ukraine
Received June 29, 2010
Abstract—Adsorption of alkylammonium chlorides by freshly precipitated hydroxides of aluminum and iron(III)
was studied. Equations most fully describing the experimentally obtained data were chosen.
The increasing variety of cationic surfactants
and their wide use in various industries  results
in contamination of open water basins with these
compounds . Although the total content of cationic
surfactants in wastewater is low, they are highly
toxic and poorly biodegradable, which predetermines
a scientiﬁ c and practical interest in the problem of their
One of the simplest and most promising methods for
recovery of cationic surfactants from industrial solutions
and wastewater is their adsorption microﬂ otation 
based on the adsorption of surfactants by specially
selected adsorbents-carriers introduced into the system
in amounts that, on the one hand, are sufﬁ cient for
nearly complete adsorption of surfactants and, on the
other hand, can be fully hydrophobized.
To conclusively solve the problem of the application
advisability of an adsorbent-carrier, it is necessary
to know the fundamental aspects of the adsorption of
cationic surfactants on their surface and to determine its
The goal of our study was to examine the adsorption
of alkylammonium chlorides (AACs) by freshly
precipitated aluminum and iron(III) hydroxides and to
choose adsorption isotherm equations that would most
fully describe experimentally obtained data.
As objects of study served aqueous solutions of AACs
containing 12 to 18 carbon atoms in the hydrocarbon
radical: dodecyl-, hexadecyl-, and octadecylammonium
chlorides (DDAC, HDAC, ODAC). Freshly precipitated
aluminum and iron(III) hydroxides were used as
Aluminum hydroxide was produced by peptization,
for which purpose aqueous ammonia was added to
a 1% solution of aluminum chloride . The resulting
precipitate was several times washed by decantation and
ﬁ ltered, after which several drops of a 0.1 M solution
of hydrochloric acid were added. The peptization
continued for 2–3 h.
Iron(III) hydroxide was produced by hydrolysis of
iron(III) chloride (Krecke method) . For this purpose,
a 2% solution of iron(III) chloride was introduced in
small portions into distilled water heated to boiling.
The solution turned bright red, and, on being cooled,
changed its coloration because of the reversibility of
the hydrolysis process occurring in accordance with the
O ' Fe(OH)
O ' Fe(OH)
Cl + 2HCl
' FeOCl + 2HCl + H
FeOCl ' FeO