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Khentov V.Ya.

Doctor of Chemical Sciences (Advanced Doctor), Professor, Southern Russian State Polytechnical University

MAIN FEATURES AND CHARACTERISTICS OF CHEMICAL AND PHYSICAL-CHEMICAL METHODS OF ANALYSIS OF SURFACTANTS

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 4-15 p.
Abstract
One of the most acute and pressing problems of sustainable development in the coming century can be providing the population with quality drinking water. According to estimates of the World Health Organization, the frequency of diseases arising from the use of poor-quality drinking water is the highest. Pollution of the environment by surfactants is a great danger to the entire biosphere. Unlike organic substances, they are not subject to degradation and, in addition to the direct toxic effect on living and plant organisms, tend to accumulate in food chains, which increases their danger to humans.
The flow of surfactants into reservoirs occurs mainly from man-made sources. With the inefficient purification of water, surfactants enter the natural reservoirs, the soil, and along trophic feeding routes reach people. Accumulating in reservoirs, surfactants have a strong toxic effect on the flora and fauna, worsen the organoleptic characteristics of water, prevent the processes of self-purification of water bodies. Even small amounts of surfactants cause abundant foaming, disrupt oxygen exchange in water bodies, and inhibit photosynthesis.
To achieve one hundred percent purification of wastewater from surfactants is almost impossible. In this connection, the search for new and improvement of existing methods of analysis of surface-active substances is very important.
The article presents the main features and characteristics of chemical and physico-chemical methods for the analysis of synthetic surfactants.
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ON THE RELATIONSHIP BETWEEN THE CONTENT OF CHEMICAL ELEMENTS IN RAW MATERIALS WITH DEBYE TEMPERATURE

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 34-41 p.
Abstract
The relationship between the content of heavy metals in plant raw material with such an important integral physical parameter as the Debye temperature of a metallic element is considered. This is confirmed by the high values of the correlation coefficient. This parameter is calculated for cadmium, lead, copper, manganese, nickel, chromium and zinc ions.
The graphical dependence of the accumulation coefficient k of heavy metals from the soil is presented for the wild grassy plants of the Lower Don. Wetweed ambrosia (Ambrosia artemisiifolia L.), tansy (Tanacetum vulgare L.), Austrian wormwood (Artemisia austriaca Pall. ExWilld.), Cedar grass (Elytrigia repens (L.)) are considered. Samples were taken at a distance of 1 km from Novocherkasskaya SDPP.
The value of the mobilization factor (the factor of technogenic enrichment) of EF is described as the ratio of the technogenic flow of a chemical element to a natural element, in the transfer of metallic elements. Dependences of the mobilization factor (EF) on the Debye temperature of the metal are presented.
The dependence of the heavy metals content in the soil-vegetation-invertebrate animals system in steppe biogeocoenoses on the Debye temperature of the metal is characterized. This will allow us to predict the possible mechanism for the transport of heavy metals in nature.
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ON THE CONNECTION OF THE PHYSICAL PROPERTIES OF METAL ELEMENTS WITH THE TEMPERATURE OF DEBAY

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 19-23 p.
Abstract
The article describes the relationship between the physical properties of metallic elements and the Debay temperature. This relationship is described for alkaline and alkaline earth metals. Previously, this phenomenon was observed for such parameters as density, melting point, melting enthalpy, boiling point, enthalpy of evaporation, heat capacity, binding energy of elements, coefficient of linear thermal expansion, compressibility coefficient, bulk modulus of elasticity, Young's modulus of elasticity, mineralogical hardness, surface tension, lattice parameter, internuclear distance, crystal lattice energy, electron work function, Fermi energy, atomic concentration and ionization energy. Within the framework of the study, a graphical dependence of the atomic-ion radius of the s-elements of group II on the Debay temperature of the metal is shown. For the given correlation, the following value of the correlation coefficient was observed, equal to 0,989. It should be noted that this dependence is also observed for the values of the atomic volume. The value of the correlation coefficient takes the value equal to 0,993. The interrelation between the average temperature coefficient of linear expansion of metals and the Debay temperature of an alkali metal is considered. These values are valid for the temperature range from 0 to 100°C. The correlation coefficient observed for the reduced dependence is 0,992. The dependence of the atomization energy of the crystals of the s-elements of the I and II groups on the Debay temperature of the metal is determined experimentally. The calculated value of the correlation coefficient is 0,992. The dependence of the sublimation energy of metals on the Debay temperature for metals is described. The value of the correlation coefficient is equal to the value 0,987. The correlation curves obtained will make it possible to characterize most fully the interrelation of the parameter under consideration and the above-mentioned quantities.
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SORPTION-PHOTOMETRIC DETERMINATION OF ANIONIC SURFACTANTS IN THE PRESENCE OF ORGANIC REAGENT

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 27-36 p.
Abstract
The article describes the characteristics of a class of surfactants and the use of substances in the petrochemical industry. The classification of anionic surfactants is considered. The main structural elements of the structure of substances of the considered class are presented. A brief description of the most commonly used methods for the analysis of anionic surfactants is given. Advantages of using photometric, extraction-photometric and spectrophotometric methods for the determination of anionic surfactants using triphenylmethane dyes are described. In the course of the study, the content of the anionic surfactant (sulfonol) in the solution was monitored spectrophotometrically using the indicator reaction with malachite green. The use of the method in question to study sorption processes in a surfactant system is justified by the fact that surfactants are able to form complex compounds (ionic associates) with organic reagents with characteristic light absorption bands.
The results of a photometric determination of an anionic surfactant (sulfonol) using an organic reagent, malachite green, are presented. The effect of the acidity of the environment on the process of adsorption of a component in aqueous solutions is described. A calibration graph for determining the concentration of the component is given.
The main thermodynamic parameters of sulfon adsorption on activated carbon, such as enthalpy (∆H), isobaric-isothermal potential (∆G) and entropy (∆S) sorption were determined during the research. The obtained research results can be used for quantitative determination of the component and modeling of adsorption mechanisms.
The main characteristics of the sorption kinetics of a surfactant (sulfanol) on active coal are calculated. Isotherms of sorption kinetics are given. The possibility of purification from the above-described component using the sorbent under consideration is described.
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ABOUT CONNECTION OF LIQUACTION WITH THE DEBYE TEMPERATURE

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 41-46 p.
Abstract
The article describes the concept of liquation. Within the framework of the research, the definition of the concept described is given. The types of liquation (zonal and dendritic) are given. It is established that a number of parameters characterizing the segregation process are related to the characteristic Debye temperature of a chemical element. The interrelation between the values of the effective atomic radius, intensity, and also the liquation coefficient from the Debye temperature is considered. The role of the values of the maximum supercooling parameter on the Debye temperature is described. The dependence of the content of elements in interdendritic volumes on the Debye temperature is considered. The dependence of the chemical composition of local regions on the Debye temperature is given. A similar trend was observed with the values of the viscosity of the molten metal. The correlation coefficients always exceeded 0.9.
It should be noted that the liquation process adversely affects the steel properties. This can affect the values of the toughness of transverse specimens. The considered dependences of the process parameters can be useful for describing the processes of eliminating the heterogeneity of steels. All this will not only improve its properties, but also describe in more detail the process of eliminating the chemical heterogeneity of steel. In addition, this will allow us considering the melting process with a change in volume. Increased interest causes the content of elements in the axes of the dendrites in the initial cast state. It was found that the distribution of elements in the axes of dendrites in interdendritic microvolumes in the structure of the pressed steel does not depend on the quenching method. For the dependence considered, the values of the correlation coefficient are calculated. The main conditions of the quenching process as well as the content of the elements in percent are given.
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