Russian Journal of Applied Chemistry, 2010, Vol. 83, No. 1, pp. 50−53.
Pleiades Publishing, Ltd., 2010.
Original Russian Text
V.V. Zheleznov, V.A. Avramenko, V.I. Kostin, A.A. Kovshun, A.V. Voit, S.V. Sukhoverkhov, 2010, published in Zhurnal Prikladnoi Khimii,
2010, Vol. 83, No. 1, pp. 52−55.
OF SYSTEMS AND PROCESSES
of Ethylenediaminetetraacetic Acid and Its Complexes
with Iron, Nickel, and Cobalt on Carbon
Materials in Nitrate Media
V. V. Zheleznov, V. A. Avramenko, V. I. Kostin, A. A. Kovshun,
A. V. Voit, and S. V. Sukhoverkhov
Institute of Chemistry, Far-Eastern Branch, Russian Academy of Sciences, Vladivostok, Russia
Received August 28, 2008
Abstract—Catalytic thermal destruction of ethylenediaminetetraacetic acid and its complexes with nickel, iron,
and cobalt in nitrate solutions on carbon materials (activated unwoven material, sibunite, and BAU-A activated
carbon) was studied. The activation energies of thermal destruction were calculated.
In some cases, the wide application of complexons
in thermal power engineering and nuclear industry
necessitates their removal from technological solutions
and industrial wastewater by using, among other
techniques, destructive methods. In this context,
decomposition of complexons in acid solutions in the
presence of heterogeneous catalysts seems to be rather
There are data on use of platinum-group metals
and carbon materials as catalysts for decomposition of
complexons. It should be noted that platinum-containing
compounds are rather expensive, but their loss is almost
inevitable; with carbon materials and, in particular, BAU,
catalyst destruction has been observed . Therefore,
a search for, and study of, new effective catalysts for
decomposition of complexons in pre-utilization treatment
of wastewater, including liquid radioactive waste (LRW),
remain scientiﬁ cally and practically topical.
The goal of our study was to test carbon materials
with a well-developed surface as catalysts for thermal
destruction of ethylenediaminetetraacetic acid (EDTA)
and to examine the effect of complexation on the rate of
Ethylenediaminetetraacetic acid was additionally
puriﬁ ed by recrystallization. Nitric acid was of special-
purity grade, and the rest of reagents, of analytically and
chemically pure grades.
As carbon catalysts served an activated nonwoven
material (ANM) manufactured by Neorganika Research
and Production Association, Sibunite-3 (0.5–1-mm
fraction), and BAU-A activated carbon. Samples were
pretreated with NaOH and HCl solutions, washed to
neutral pH, and dried in air. Metal complexes were
prepared with a 1 : 1 metal : ligand ratio.
An aliquot of a solution under study (40 ml), with a
prescribed concentration of a metal complex and nitric
acid, was heated in a thermostated cell to a prescribed
temperature, after which a weighed portion of a catalyst
was added under vigorous agitation. Samples (0.7 ml)
were taken at regular intervals of time. The sampling time
was adjusted depending on the decomposition rate. In
experiments with EDTA, an urotropin buffer solution and
an indicator were added to a sample diluted to 50 ml and
then titration with a standard lanthanum nitrate solution