Russian Journal of Applied Chemistry, 2010, Vol. 83, No. 10, pp. 1857−1861.
Pleiades Publishing, Ltd., 2010.
Original Russian Text
O.N. Chaikovskaya, E.A. Karetnikova, I.V. Sokolova, O.V. Vodyankina, A.S. Knyazev, A.A. Kreiker, 2010, published in Zhurnal
Prikladnoi Khimii, 2010, Vol. 83, No. 10, pp. 1718−1721.
AND INDUSTRIAL ORGANIC CHEMISTRY
Effect of Humic Acids on Biodegradation
of 2-Methyl-4-chlorophenoxyacetic Acid:
A Chromatographic Study
O. N. Chaikovskaya
, E. A. Karetnikova
, I. V. Sokolova
, O. V. Vodyankina
A. S. Knyazev
, and A. A. Kreiker
Tomsk State University, Tomsk, Russia
Siberian Physicotechnical Institute, Tomsk, Russia
Institute for Water and Environmental Problems, Far-Eastern Branch,
Russian Academy of Sciences, Khabarovsk, Russia
Received December 30, 2009
Abstract—The effect of humic acids on biodegradation of 2-methyl-4-chlorophenoxyacetic acid in the active
sludge medium was studied by analyzing their solutions by chromatography–mass spectrometry. The mechanism
of the transformation of the herbicide in the presence of humic acids was examined.
In consideration of processes occurring in aqueous
media, it is necessary to take into account the presence
of humic substances (HSs). In large rivers of the
Russian Far East (Bureya, Zeya, Amur), 20–50% of
total carbon is in the form of HSs. The lifetime of these
substances is hundreds and thousands of years. Their
formation involves synthesis of numerous products
of random reactions . Natural selection of the most
stable products determines their extremely complicated
Humic substances are very difﬁ cult to study, and
their numerous functions are still poorly understood.
Humic substances can act as sorbents , hydrolysis
catalysts, photosensitizers, and quenchers; they can
absorb light and transfer the light energy to other
components of aqueous solutions, in some cases
strongly affecting the photolysis of xenobiotics .
HSs can act as photosensitizers in irradiation with light
having the wavelengths larger than 290 nm . The
capability of HSs to produce active oxygen species
after irradiation  and to photoinduce transformations
of herbicides is known . At the same time, studies in
this direction are few and largely fragmentary. There
are contradictory data on the mutual effect of humic
substances and ecotoxicants in utilization. Humic acids
(HAs) considerably accelerate the photodegradation of
4-chloro-2-methylphenol  and 2,4,6-trimethylphenol
 but decrease the efﬁ ciency of photodegradation
of Bensulfuron Methyl herbicide. Basic studies are
required to formulate principles of the action on water
pollutants and to develop principles of monitoring the
pollution and regeneration of water, with consideration
of the effect of HSs and their most important fraction,
HAs, whose role is yet insufﬁ ciently understood.
The presence of HAs in a system leads to changes
in the quantitative composition of products of glucose
fermentation with separate strains of bacteria .
Humic acids isolated from various natural water
bodies after UV irradiation decreased the bacterial
activity of microorganisms of Lake Fiolen (Sweden).
Such inhibition correlated with the formation of
peroxy compounds. On the contrary, enhancement
of the bioactivity did not correlate with the chemical
structure of nonirradiated HA solutions. Studies of
the effect of HAs on the biodegradation of separate
toxicants showed that HAs in a concentration of