N. V. Yudina

Effect of magnetic field on the paramagnetic, antioxidant, and viscosity characteristics of some crude oils

The effect of a magnetic field on the structural and rheological properties of crude oils with various concentrations of resins, asphaltenes, and paraffin hydrocarbons was examined. It was found that magnetic treatment leads to substantial changes in the paramagnetic, antioxidant, and viscosity characteristics of paraffin-base and high-viscosity oils. A factor that characterizes the quantity of inhibition centers increases with an increase in the amount of alcohol-benzene-extractable resins in the oils. The time of complete recovery of paramagnetic and antioxidant properties coincides with the recovery time of the rheological characteristics of petroleum.

Antioxidants in the water-soluble carbohydrate fractions of the moss Sphagnum fuscum and sphagnum peat

The effect of various mechanical treatment conditions on changes in the composition and antioxidant activity of the polysaccharide fractions of the moss Sphagnum fuscum and sphagnum moss peat was studied. It was found that mechanochemical treatment changed the composition of polysaccharide moss and peat fractions, and the antioxidant activity of polysaccharides depended on the hydroxyarene aglycon content of polysaccharides.

Association constants of modified humic acids with biocides of the triazole series: Cyproconazole and tebuconazole

The interaction of humic acids with biocides of triazoles in dependence on the concentration of components in solutions was investigated by spectrofluorimetry. The complex behavior of intermolecular interactions between biocides and humic acids, including donor-acceptor and hydrophobic bonds, was established. The effect of conditions of mechanochemical modification of humic acids and pH on the efficiency of interaction with biocides is shown.

Composition of humic acids in peats with various degrees of humification

The structure peculiarities of humic-like substances in plants at a dying stage, humic acids in peat-forming plants humified for two years, and native peats at branches of the Vasyugan bog were determined using spectroscopic techniques. The polydispersity and absorbance of humic acids increased with the degree of humification; the concentration of aromatic and carbonyl-containing carbon in the chemical composition of humic acids increased.

Effect of Constant Magnetic Field on the Rheological Properties of High-Paraffinicity Oils

The effect of constant magnetic field on the rheological properties and freezing point of a number of high-paraffinicity oils is studied. It is established that the rheological behavior of oils in a magnetic field depends on the content of paraffin hydrocarbons, resins, and asphaltenes. An increase in the main rheological parameters upon the action of magnetic field is observed for high-paraffinicity oils with the increased content of neutral resins and a decrease, for high-paraffinicity oils with the increased content of acid resins. The activation energy of viscous flow is determined and the dependence of the rate of the recovery of rheological properties on the parameters of magnetic treatment and the ratio between the content of paraffin hydrocarbons and resin–asphaltene components is established for the magnetically treated oils of different compositions.

Adsorption properties of modified peat toward organic compounds and heavy metals

The adsorption properties of peat modified by mechanical activation in the presence of iron oxide hydroxide were studied. Based on the results of the determination of adsorption activity and microcalorimetric studies, it was established that physical absorption processes predominate on the interaction of the modified peat sorbents with a model organic substance and the aqueous solutions of metal salts. It was demonstrated that new types of sorbents with high sorption properties can be obtained based on peat mechanically activated in the presence of water treatment wastes

Activation of the biochemical processes in an oil-contaminated soil using a light-correcting film and humic acids

It was shown that the use of a light-correcting film as a covering material for an oil-contaminated soil in combination with humic acids increased the number of the main physiological groups of the soil microorganisms responsible for the development of the soil’s fertility (heterotrophic bacteria, actinomycetes, and micromycetes) by 60–100 times. The activity of the soil enzymes (catalase, dehydrogenase, polyphenoloxidase, peroxidase, and urease) increased by 3–6 times. The biochemical oxidation of oil hydrocarbons in the soil became significantly more intense.

Change in the Rheological Properties of High‐Paraffin Petroleums under the Action of Vibrojet Magnetic Activation

The influence of the method of vibrojet magnetic activation on the rheological properties of high‐paraffin petroleums has been investigated. The maximum decrease in the rheological characteristics of the petroleums was obtained in 20‐min vibrojet treatment. It has been noted that the maximum effect of vibroaction is observed for petroleums with a higher‐than‐average content of paraffins. The role of the magnetic component contributing to the decrease in the congelation point and the amount of the basic sediment in the petroleums under study has been shown.

Influence of the conditions of mechanical activation of lignite on the composition and sorption properties of humic acids isolated from it

The results of the study of the influence of mechanical activation of lignite on the composition of isolated humic acids and their adsorption to the quartz river sand were generalized. The changes in the composition of humic acids after adsorption to the sand, which are an evidence of a significant role of phenolic hydroxyls in the process, were demonstrated.

Influence of aggregation of asphaltenes on the rheological properties of oil

Photon correlation spectroscopy was used to determine the threshold concentrations of n-heptane for phase transitions of asphaltenes in model systems for two types of oil. The rheological properties exhibited by high-paraffin oil in the asphaltene aggregation process were analyzed. It was shown that the presence of resin and paraffi n fractions in oil prevents phase transition of asphaltenes at the threshold concentration of n-heptane for the model system, so that a higher precipitant concentrations is required for aggregation of asphaltenes and formation of oil sludge.