The purpose of this work was to create magnetic nanocatalysts that could be used for the oxidation of organic water pollutants – phenol and its derivatives – and to determine the physicochemical characteristics of the catalysts. The development of such active nanocomposite catalysts would solve the environmental problem in the Republic of Kazakhstan in the field of wastewater treatment from organic impurities, including phenols, and would also contribute to the subsequent creation of domestic production of oxygen-containing compounds, since almost the entire spectrum of oxygen-containing compounds for various industries is imported into the Republic. Nanosized magnetic composites based on Fe and Co were obtained by chemical deposition, in some cases, using polyethyleneimine and polyvinylpyrrolidone. It was shown that the interaction between nanoparticles and the polymer takes place in the case of a CoFe2O4 catalyst stabilized with polyvinylpyrrolidone or polyethyleneimine, which may indicate the efficient formation of nanocomposites. According to the IR study, for the CoFe2O4 nanocomposite stabilized with polyvinylpyrrolidone, the absorption bands at 735, 663, 649, 626 cm–1 are natural vibrations for the composite nanoparticles embedded in a polyvinylpyrrolidone matrix. The synthesized nanocomposites were tested in the oxidation of phenol with oxygen. The results demonstrate that the catalysts are promising both for the purification of industrial wastewater from phenol and for the synthesis of oxygen-containing compounds in the liquid phase under mild conditions.

The development of new catalytic systems based on cobalt and iron compounds for the production of oxygen-containing compounds is an urgent task of chemical technology. The purpose of this work is the synthesis of CoFe₂O₄ stabilized with polyvinylpyrrolidone (PVP), the study of the catalyst by physico-chemical research methods, and the determination of the effectiveness of the CoFe₂O₄/PVP catalyst in the phenol oxidation reaction. In this work, magnetic composites CoFe₂O₄ and CoFe₂O₄ stabilized with polyvinylpyrrolidone were synthesized by co-deposition. A comparison of the characteristics of the properties of the synthesized cobalt (II) ferrite (CoFe₂O₄) and the composite material CoFe₂O₄/PVP based on it is carried out. The obtained samples were examined using X-ray phase analysis (XRD), the Debye–Scherrer method, scanning electron microscopy (SEM), Mossbauer and IR Fourier spectroscopy, as well as thermogravimetric analysis (TGA). The textural properties were determined based on the analysis of nitrogen isotherms. The catalytic properties of the synthesized materials in the process of phenol oxidation in the presence of hydrogen peroxide are considered. The analysis of the reaction mixtures by HPLC obtained by the oxidation of phenol in the presence of a CoFe₂O₄/PVP catalyst showed a decrease in the concentration of phenol in the first 15 min of the process (by 55–60%), and then within 30 min, the concentration of phenol decreased to 21.83%. After 2 h of the process, the conversion of phenol was already more than 95%. The final sample after the reaction contained 28% hydroquinone and 50% benzoquinone. It was found that the synthesized magnetic composites exhibit catalytic activity in this process.

This study investigated the macro- and microelement profiles and bioactive substances (BAS) in the herbaceous species of the genus Rheum collected from two villages near Almaty, Kazakhstan, and the accumulation of heavy metals (HMs) in wild plants of Eastern Kazakhstan. Representative zonal species from the steppes and desert–steppes (Eastern Kazakhstan) were analyzed—totaling one hundred samples across 18 species from six families. According to the research, different plant species have a selective ability to accumulate heavy metals, even when growing in the same type of soil. Long-term observations reveal dominant patterns of HM (Cu, Zn, Mn, Co, Pb, Cd) occurrence in dry-steppe vegetation. It was found that Cu and Co demonstrate moderate bioadsorption with minimal accumulation, while Zn, Mn, and Pb show strong biological enrichment. Cadmium falls under elements with pronounced biological retention. Copper and cobalt are classified as moderately absorbed with limited buildup. Native plants in this region contain substantially greater amounts of lead relative to cobalt, and reflect cadmium–zinc geochemical specificity: Cd 3.85, Zn 0.15, Mn 0.10, Pb 0.09, Co 0.07, Cu 0.04, per Clark’s concentration index. Samples of collected Rheum tataricum L. in the village of Miyaly were found to have higher levels of flavonoids, phenolic compounds, and organic acids, while raw materials from the village of Bakbakty showed increased accumulation of anthracene derivatives and tannins. Flavonoids constituted the largest proportion of the studied groups of biologically active substances in both samples, confirming the high biological and pharmacological value of the plant material studied. The results obtained during the research can be successfully applied to the development of a strategy for the conservation of plant biodiversity in the studied areas and the sustainable management of plant resources.

This study investigates the effect of dibenzothiophene on the hydrogenation of aromatic hydrocarbons over bifunctional catalysts based on mesoporous Al-HMS aluminosilicates. Mesoporous aluminosilicate materials with different Si/Al ratios varying from 10 to 70 were synthesized and employed as supports for Ni-Mo-Al-HMS-H-bentonite catalysts. The physico-chemical features of the materials were characterized using ICP-OES, nitrogen physisorption at low temperatures, XRD, FTIR, and pyridine adsorption FTIR spectroscopy. Catalytic activity was evaluated in the hydrogenation of a model mixture of 2-methylnaphthalene and n-hexadecane at temperatures between 220-300°C and at 6 MPa H2. The optimal catalytic performance was observed for the sample with a Si/Al ratio of 10, displaying high conversion and selectivity to 2-methyldecalin as a result of sufficient Brønsted and Lewis acidity. The presence of dibenzothiophene leads to a decrease in conversion and selectivity due to sulfur-induced catalyst poisoning and shifts the optimal reaction temperature from 240 to 260°C. These findings highlight the important role of acid properties of mesoporous aluminosilicates in hydrogenation and hydrotreatment processes of aromatic compounds.