ISSN 1070-4272, Russian Journal of Applied Chemistry, 2008, Vol. 81, No. 12, pp. 2104–2107. © Pleiades Publishing, Ltd., 2008.
Original Russian Text © N.M. Panich, A.F. Seliverstov, B.G. Ershov, 2008, published in Zhurnal Prikladnoi Khimii, 2008, Vol. 81, No. 12, pp. 1991–1995.
Photooxidative Decomposition of Sodium Dodecyl Sulfate
in Aqueous Solutions
N. M. Panich, A. F. Seliverstov, and B. G. Ershov
Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Moscow, Russia
Received July 30, 2008
Abstract—Kinetic features and the mechanism of photooxidative decomposition of sodium dodecyl sulfate in
an aqueous solution under the action of pulsed short-wavelength UV light with a continuous spectrum upon
introduction of hydrogen peroxide was studied.
Surfactants are widely used in the industry and
households. They belong to the most widely occurring
contaminants contained in wastewater.
An efficient way to purify wastewater to remove
surfactants is their oxidative decomposition to CO
O. Ozone is most frequently used for this purpose
(oxidation potential 2.07 V) . However, ozone rather
effectively oxidizes nonionogenic surfactants, but is
considerably less efficient with anion-active surfac-
tants (AAS) .
The hydroxy radical
OH is a stronger and more
effective oxidizing agent (oxidation potential 2.8 V).
In contrast to ozone, it is not a selective oxidizing
agent and equally effectively interacts with all organic
substances, including surfactants .
After the appearance of pulsed xenon lamps with
a continuous spectrum, it became possible to gener-
OH radicals in the reaction H
+ hν → 2
The method of photochemical oxidation in the pres-
ence of hydrogen peroxide has been used to deactivate
EDTA-containing solutions , and the mode of nearly
complete decomposition of the complexone was found.
The aim of the present study was to examine spe-
cific features of decomposition of sodium dodecyl
sulfate (an AAS) in aqueous solutions by hydroxy radi-
cals formed in H
photolysis under irradiation with a
(pulse width 100 μs, pulse repetition frequency f = 2 Hz)
was used in the experiment. Samples were irradiated in
an open quartz cell with an IFP 1200 Xe lamp with a
flash energy of 100 J. The cuvette with a solution was
placed at a distance of 1 cm from the lamp and was
cooled with an air flow in the course of irradiation. The
volume of the reaction mixture was 10 ml.
The pulsed Xe lamp provides a continuous-spec-
trum light over the entire UV spectral range (200–
400 nm). The light intensity was measured using the pro-
cedure described in . The intensity I of the light flux
incident on the cuvette was 3.8
The operation stability of the xenon lamp was moni-
tored in the course of the study.
Sodium dodecyl sulfate (SDS, C
was chosen as object of study. The aqueous solutions
contained up to 100 mg of SDS per liter of a solution.
The SDS concentration was found using the extrac-
tion-photometric determination with Methylene Blue
by the procedure described in .
The degree of AAS decomposition was evaluated by
measuring the chemical oxygen demand (COD) [7, 8].
The reaction course was also monitored by changes
in optical spectra. The absorption spectra of the solu-
tions in the UV and visible spectral ranges were re-
corded with an SF-2000 spectrophotometer in a quartz
cuvette with an optical path length of 1 cm.
The hydrogen peroxide concentration in the solu-
tions was determined from the concentration of the
peroxide complex [TiO
OF SYSTEMS AND PROCESSES
Al’fa-02 pulsed UV installation with an average
electric power applied to the lamp equal to 200 W