Russian Journal of Applied Chemistry, 2010, Vol. 83, No. 2, pp. 237−241.
Pleiades Publishing, Ltd., 2010.
Original Russian Text
L.N. Grigor’ev, T.A. Aleksandrova, 2010, published in Zhurnal Prikladnoi Khimii, 2010, Vol. 83, No. 2, pp. 239−243.
OF SYSTEMS AND PROCESSES
Properties of Vapor and Gas Adsorption at Low Concentrations
L. N. Grigor’ev and T. A. Aleksandrova
St. Petersburg State Chemical Pharmaceutical Academy, St. Petersburg, Russia
St. Petersburg State Technological University of Plant Polymers, St. Petersburg, Russia
Received May 19, 2009
Abstract—The isotherms of vapor adsorption of isobutyl alcohol, benzene, sulfur dioxide, and nitrogen monoxide
on activated carbons with varied structural parameters and oxidation degrees were studied. The advisability of
performing special research into vapor and gas adsorption at low concentrations was demonstrated.
a = exp –B
log + exp –B
The current methods of puriﬁ cation of atmospheric
air, which is used in manufacture of sterile drug products
and in biotechnology, provide removal of microorganisms
and mechanical particles, whereas do not provide removal
of steam and gas pollutants. At the same time, the pres-
ence of the latter is dangerous, because they may adsorb
(and thus concentrate) on the surface of raw materials,
substances, pharmaceuticals, formulations, and drug
products. A possibility of concentrating gases and vapors
is conﬁ rmed by the data on the content of xenobiotics on
surfaces of plants , foods , and metals .
The concentration of vapors and gases and the adverse
effect exerted by them on the materials is especially
important in view of wide introduction of electronic
technologies, computer technologies, in particular. The
above problem is one of main reasons responsible for
a premature breakdown of blocks, which largely stimu-
lated development of the speciﬁ cations  for quality of
atmospheric air. According to them, the pollution con-
centration in air must not exceed the maximum and daily
mean limiting permissible concentrations (LPCs).
In this respect, preparation (puriﬁ cation) of air used
in various technologies is the urgent problem.
The preferable method of air purification at low
concentrations of pollutants is adsorption on activated
carbons. One of main characteristics used in determining
the necessary adsorbent mass and duration of its work
is the equilibrium adsorption, which is determined from
experimental adsorption isotherm or by calculation. For
microporous activated carbons, the adsorption capacity
and equilibrium concentration of pollutants in air are
calculated from the Dubinin–Radushkevich equation.
where а is adsorption capacity, W is the limiting
volume of adsorption space (W
in micropores and W
in supermicropores), ν is the molar volume, В structural
for micropores and В
β is the similarity coefﬁ cient, Т is adsorption temperature,
is the saturated vapor pressure of adsorbate, and Р, its
Note, the experimental isotherms obtained with ac-
counting for the low concentrations of pollutants were
scarce. Therefore, the possibility of using Eq. (1) for
calculation of adsorption at the pollutant concentrations at
the LPC level was unclear. Commonly, studying the equi-
libria in the system gas(vapor)-activated carbon begins at
low adsorption capacities providing a ﬁ lled adsorption