Education of the republic of uzbekistan tashkent state technical university named after islam karimov

Keywords
. Angren coal, asphaltene, adsorption, isotherm, differential heat, entropy, adsorption 
calorimeter. 
Introduction
Currently, industrial wastewater is heavily contaminated with a variety of chemicals. A 
fairly common class of chemical compounds found in the wastewater of the wood-chemical 
industry, enterprises producing synthetic detergents, is the class of carbonyl compounds. 
Carbonyl compounds are widely used in the medical, chemical and forestry industries. 
Aldehydes and ketones get into wastewater during accidents at enterprises producing chemical 
materials - synthetic fatty acids, building materials, for example, linoleum, foam. 
Carbon microporous adsorbents (activated carbon, activated fibers and fabrics) are a class 
of high molecular weight solid porous carbon materials that absorb substances of various 
chemical nature (in gaseous, vapor and liquid media up to a certain surface
[1,
2]. According to 

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the classification of M.M. Dubinin [3], based on the sorption mechanisms occurring in 
adsorption pores and capillary pores, the pores of various adsorbents are divided into the 
following types: micropores, macropores (equivalent radius r more than 100-200 nm), 
mesopores. (from 2 to 50 nm).Carbon microporous adsorbents differ significantly from materials 
such as coke, pumice, graphite [4], since they contain micropores and super pores. In the same 
way, they differ from coal [5] in that they have a relatively large surface area (up to 100 m2 / g 
and above) due to their small particle size, they belong to non-porous carbon adsorbents. 
Micropores and super micropores are actually adsorbed on their pores [6] because they 
are critical for the adsorption of gases and vapors and, in many cases, for the adsorption of the 
liquid phase. It depends on the structure and geometric surface of the adsorbates. Its value is ~ 
400–1400 m2 / g according to [8], ie, it has a condensed flat band structure, which is 15–55% of 
the theoretically possible value of 2630 m2 / g obtained for a hypothetical model of pure 
aromatic carbon in hexagonal form [9].The volume of micropores and super pores usually ranges 
from 0.2 to 0.6 cm3 / g [10]. For the best samples of carbon adsorbents, it can reach 1.3–1.5 cm3 
/ g [11, 12]. 
Adsorption processes are used to extract some valuable product that is in the form of an 
impurity in gas or water, for example, the extraction of phenols from water with coal, or the 
extraction of valuable solvent vapors (benzene, acetone) from the air with silica gel. 
The adsorbed substance is then recovered in free form by desorption methods. At the Institute of 
General and Inorganic Chemistry of the Academy of Sciences of the Republic of Uzbekistan, 
volumetric studies of the adsorption of polar and non-polar molecules on the surface of 
microporous adsorbents on a micro calorimeter in a high-vacuum adsorption unit are carried out 
[13-20]. 
Adsorption is an effective regenerative method for de-penalization of wastewater. 
Activated carbons, coke, ash, slag’s, etc. can serve as sorbents. After saturation, the coal is 
regenerated at 70 ° C with benzene, the phenol-benzene solution is treated with alkali, and the 
purified benzene is reused in the process. 
From the recovered coal benzene is stripped off with steam and the coal is used again for water 
purification. After 15 cycles of adsorption-desorption, the coal is subjected to thermal 
regeneration at 800 ° C. 
The adsorption-desorption isotherm of gases and vapors in the range of variation of the 
relative pressure of the adsorbate p / ps (0 ... 1) allows one to estimate the structure of the 
material (monolayer capacity, specific surface area, volume of micro- and mesopores, structural 
and differential distribution curve of adsorption volume over pore diameter ). 
High-precision methods for measuring adsorption activity are the gravimetric method (according 
to the weight gain of the adsorbent) or the volume method (according to the decrease in the 
amount of adsorbate in the cell after contact with the adsorbent) [21-24]. These methods also 
require special equipment, including deep evacuation of the material, and prolonged observation 
during testing. 
Object and research methods. The adsorption isotherm of benzene on the obtained 
adsorbent was determined in the pressure determination section of the high-vacuum adsorption 
device. The differential heat of adsorption is measured by theoretical calculations of the pressure 
and energy values coming from the DAK 1-1 calorimeter in the Tian-Calvet model. 
The volumetric and capillary (liquid) methods were used to determine the adsorption isotherm. 
The accuracy of the adsorption isotherm is 0.1%, and that of heat is up to 1% [25]. 
The adsorption of benzene was carried out at 303 K. on a sample of activated carbon adsorbent 
activated with local Angren carbon.