Russian Journal of 2288Applied Chemistry, 2010, Vol. 83, No. 11, pp. 1930−1934.
Pleiades Publishing, Ltd., 2010.
Original Russian Text © G.V. Chistyakova, S.A. Koksharov, 2010, published in Zhurnal Prikladnoi Khimii, 2010, Vol. 83, No. 11, pp. 1898−1802.
OF SYSTEMS AND PROCESSES
Absorption of Atmospheric Oxygen by Agitated
Weakly Alkaline Solutions of Surfactants
G. V. Chistyakova and S. A. Koksharov
Institute of Solution Chemistry, Russian Academy of Sciences, Ivanovo, Russia
Received May 20, 2009
Abstract—Volumetric analysis of the decomposition kinetics of sodium hydroxymethylsulﬁ nate was performed
to study the absorption of atmospheric oxygen by surfactant solutions agitated in various modes at 353 K. The
application of the Danchwerts model of surface renewal made it possible to evaluate the contribution made by
changes in driving forces in the stages of O
absorption and solvation to the overall effect of accelerated gas
absorption. The intensifying inﬂ uence of surfactants on the process of oxygen absorption, manifested in an immobile
ﬂ uid and at slow solution agitation rates, is eliminated by the oppositely directed changes in the mass transfer and
solubility of oxygen at the phase boundary in the transition and turbulent ﬂ ow modes.
The absorption of atmospheric oxygen plays an
important part in numerous biological, chemical, and
industrial processes. Absorbed oxygen can both exert
positive inﬂ uence on the course of reactions [1, 2]
and adversely affect the state of systems [3, 4], which
necessitates control over the absorption of oxygen. This
is done by various methods, e.g., by applying gradient
magnetic ﬁ elds  or by changing the surface properties
of a solution via introduction of surfactants [6–8]. In
doing so, surfactants with various chemical structures
can either decelerate the absorption of oxygen  or
make this process many times faster . However, the
role of surfactants in the mass transfer in a gas–ﬂ uid
system remains not quite clear, especially for solutions
subject to hydromechanical perturbations.
The goal of our study was to examine the effect of
surfactants on the adsorption of oxygen at the gas–ﬂ uid
phase boundary under agitation.
The role of surfactants was played by nonionogenic
preparations based on an oxyethylated fatty alcohol
H (I) and a triethanolamine
salt of sulfoacid of oxyethylated alkylphenol
The concentration of the surfactants in solutions was
0.2 g l
, which exceeds the critical micelle concentration
(CMC) because the CMCs of the above compounds at
293 K are 0.15 and 0.10 g l
, respectively, and tend to
decrease with increasing temperature .
To characterize the ﬂ uid ﬂ ow modes, we calculated
the Reynolds number :
Re = Ud(ρ/μ), (1)
where U = ω(d/2) is the linear ﬂ ow velocity of a solution
on the periphery; ω, angular rotation rate; d, vessel
diameter; ρ, solution density; and μ, solution viscosity.
The data obtained are listed in Table 1.
The amount of oxygen absorbed by the solutions was
determined by using sodium hydroxymethylsulﬁ nate
(SHMS) whose oxidation under aerobic conditions
at a temperature of 353 K is limited by the interphase
transfer of the oxidizing agent . The content of
SHMS in the technical-grade preparation rongalite [TU
(Technical Speciﬁ cation) 6-14-61–79] was 72%.
SHMS solutions were oxidized in a ﬂ ask with
a reﬂ ux and two-blade anchor stirrer at a temperature of