ISSN 1070-4272, Russian Journal of Applied Chemistry, 2014, Vol. 87, No. 5, pp. 651−655. © Pleiades Publishing, Ltd., 2014.
Original Russian Text © T.S. Urazova, A.L. Bychkov, O.I. Lomovskii, 2014, published in Zhurnal Prikladnoi Khimii, 2014, Vol. 87, No. 5, pp. 664−668.
AND POLYMERIC MATERIALS
Humic acids (HAs) are an essential step in exchange
processes in the biosphere, including the organic carbon
cycle [1, 2]. Amphiphilic properties ensure chemical
binding of humic substances with various inorganic and
polar organic compounds . Therefore, studies in the
ﬁ eld of using humic acids for the removal of various
contaminants or for remediation of soils in which the
organic (humic) component has been removed from the
inorganic component by various destructive treatments
are particularly topical .
However, isolation of humic acids from natural sources
containing, apart from humic acids, a large set of diverse
organic substances is difﬁ cult . The richest source of
humic acids is brown coal [6–8]. A signiﬁ cant fraction of
the world’s brown coal resources is located in Russia .
On the other hand, brown coal oxidized with atmospheric
oxygen is a substandard raw material for power engineer-
ing and is dumped. Utilization of this brown coal as a
source of humic acids is promising from the viewpoint
of comprehensive use of natural resources .
The modern mechanochemical approaches to process-
ing of natural resources, in particular, of brown coal, allow
the yield of water-soluble humic acids to be considerably
increased [9–11]. At the same time, there is acute need
for the development of solid-phase mechanochemi-
cal methods for modiﬁ cation of the structure of humic
substances and introduction of an additional amount of
functional groups responsible for the sorption processes
[12, 13]. From the viewpoint of the development of sor-
bents for heavy metals, phenoxy and carbonyl groups at
aromatic rings are the most promising. Their capability
to bind heavy metals in chelate complexes was proved
The goal of this study is mechanochemical modiﬁ ca-
tion of the structure of brown coal humic acids and evalu-
ation of the efﬁ ciency of using the product as sorbent for
heavy metal ions.
The following chemicals were used: sodium hydroxide
(analytically pure grade, Laverna), sodium percarbon-
hydrochloric acid (chemically pure grade, Reakhim),
tris(hydroxymethyl)aminomethane (ultrapure grade,
Mechanochemical Modiﬁ cation of the Structure of Brown
Coal Humic Acids for Preparing a Sorbent for Heavy Metals
T. S. Urazova
, A. L. Bychkov
, and O. I. Lomovskii
Institute of Solid State Chemistry and Mechanochemistry, Siberian Branch,
Russian Academy of Sciences, ul. Kutateladze 18, Novosibirsk, 630128 Russia
Novosibirsk State University, pr. Karla Marksa 20, Novosibirsk, 630073 Russia
Received February 6, 2014
Abstract—Mechanochemical modiﬁ cation of the structure of brown coal humic acids with classical base (NaOH)
and oxidizing base (Na
) reagents was studied. Treatment of brown coal under these conditions leads
to an increase in the degree of recovery of humic acids without breaking the macrostructure of the molecules.
The reaction with the base reagent leads to an increase in the content of carboxy groups at hydrocarbon chains,
whereas the action of the oxidizing base reagent leads to an increase in the content of phenolic and carboxy groups
at aromatic rings, with the formation of chelating structures. The samples obtained show high performance as
sorbents for heavy metals.