CdS nanoparticles were successfully synthesized using cadmium acetate and sodium sulfide as Cd and S precursors, respectively. The effect of using sodium thiosulfate as an additional sulfur precursor was also investigated (combined milling). The samples were characterized by XRD, Raman spectroscopy, XPS, UV-Vis spectroscopy, PL spectroscopy, DLS, and TEM. Photocatalytic activities of both CdS samples were compared. The photocatalytic activity of CdS, which is produced by combined milling, was superior to that of CdS, and was obtained by an acetate route in the degradation of Orange II under visible light irradiation. Better results for CdS prepared using a combined approach were also evidenced in photocatalytic experiments on hydrogen generation. The antibacterial potential of mechanochemically prepared CdS nanocrystals was also tested on reference strains of E. coli and S. aureus. Susceptibility tests included a 24-h toxicity test, a disk diffusion assay, and respiration monitoring. Bacterial growth was not completely inhibited by the presence of neither nanomaterial in the growth environment. However, the experiments have confirmed that the nanoparticles have some capability to inhibit bacterial growth during the logarithmic growth phase, with a more substantial effect coming from CdS nanoparticles prepared in the absence of sodium thiosulfate. The present research demonstrated the solvent-free, facile, and sustainable character of mechanochemical synthesis to produce semiconductor nanocrystals with multidisciplinary application.

Wheat is the main cereal crop in Kazakhstan and fertilizers play an important role in enhancing harvest growth. In this study, the impact of new sulfur-containing fertilizers on the growth and yield of wheat was evaluated, and the resistance of varieties to Puccinia triticina Erikss was also investigated. (also known as Puccinia recondite Rob. ex Desm.) for recommendations in agriculture. The study was conducted from 2017 to 2020 in a nursery and greenhouse. The sulfur-containing fertilizer contains nutrients that allow you to extend the duration of absorption by the plant, thereby extending the period of their availability to plants, compared to conventional preparations. By encapsulating molten elemental sulfur and impregnating with a solution of calcium polysulfide, a long-acting compound based on amorphous and monocalcium phosphate was developed. The sulfur is in a water-soluble sulfate form, which, in turn, is slowly oxidized by bacteria and retained in the soil. Three different types of the developed sulfur-containing nano-particle have been used to test in greenhouses and nurseries: powdered, pasty sulfur-containing composition, and a solution of calcium polysulfide. The results showed that the use of powdered and dissolved sulfur-containing fertilizers contributed to the early ripeness and increased productivity of wheat. Wheat varieties were tested for the presence of key Lr genes that determine resistance to brown rust. The Omskaya 29 sample showed an immune response according to phytopathological assessment, and molecular screening revealed four resistance genes. The new sulfur-containing product is recommended for improving wheat productivity in agriculture, and the Omskaya 29 variety can also be used as a valuable breeding material resistant to brown rust.

The concentration of tritium has been determined in well waters, streams and atomic lakes in the Sarzhal, Tel'kem, Balapan and Degelen Mountains areas of the Semipalatinsk Test Site. The data show that levels of tritium in domestic well waters within the settlement of Sarzhal are extremely low at the present time with a median value of 4.4 Bq dm(-3) (95% confidence interval:4.1-4.7 Bq dm(-3)). These levels are only marginally above the background tritium content in surface waters globally. Levels in the atomic craters at Tel'kem 1 and Tel'kem 2 are between one and two orders of magnitude higher, while the level in Lake Balapan is approximately 12,600 Bq dm(-3). Significantly, levels in streams and test-tunnel waters sourced in the Degelen Mountains, the site of approximately 215 underground nuclear tests, are a further order of magnitude higher, being in the range 133,000--235,500 Bq dm(-3). No evidence was adduced which indicates that domestic wells in Sarzhal are contaminated by tritium-rich waters sourced in the Degelen massif, suggesting that the latter are not connected hydrologically to the near-surface groundwater recharging the Sarzhal wells. Annual doses to humans arising from the ingestion of tritium in these well waters are very low at the present time and are of no radiological significance.

In this work, we have developed a facile, dry, and environmentally friendly mechanochemical method for the synthesis of cadmium sulfide (m-CdS) nanoparticles in a planetary ball mill using non-toxic precursors. Thiourea was for the first time used as a precursor of sulfide ion in room temperature solid state ball milling synthesis. For comparison of the mechanochemical approach with others, cadmium sulfide nanoparticles were also prepared using the solvothermal method (s-CdS). The crystal structure of cadmium sulfide nanoparticles was studied by XRD, the qualitative chemical band properties were examined by Raman scattering and x-ray photoelectron spectroscopy analysis, and particle morphology and microstructure were investigated by scanning electron microscopy and transmission electron microscopy methods. The sizes of the m-CdS nanoparticles had 5–6 nm in diameter, which is 10 times smaller than the diameter of s-CdS nanorods. The photocatalytic activities of as-prepared cadmium sulfide nanoparticles on the dye degradation and hydrogen production by water splitting were evaluated and the antibacterial activities were also tested. The photocatalytic activity of m-CdS was superior to that of s-CdS in the degradation of Orange II under visible light irradiation. Better results for m-CdS were also evidenced in photocatalytic experiments on hydrogen generation. The maximum rate of hydrogen evolution for m-CdS was 191.9 µmolg⁻¹h⁻¹ at the 120th min,while this indicator for s-CdS was only 58.0 µmolg⁻¹h⁻¹ at the same irradiation time.The better effect of m-CdS was evidenced also in an antibacterial study (namely against gram-positive bacteria).

The task of this article is to update, develop and introduce into scientific practice the method of "mechanochemical recrystallization" in solid-phase systems with small additives of the liquid phase of the solvent and solid-phase precursors to stabilize the formed nanoparticles. The essence of this method is shown using the example of mechanical activation of the S–AgNO3–NH4X system, where X = Cl, Br, I, with the addition of dimethyl sulfoxide (DMSO), and the resulting mechanochemical synthesis of sulfur-containing nanocomposites S/AgX with the controlled content of sulfur nanoparticles (nanosulfur). The predetermined content of nanosulfur in nanocomposites is ensured by a continuous process of dissolution-crystallization (recrystallization) of starting sulfur in the DMSO medium in a mechanochemical reactor. The proposed technical solution made it possible to obtain S/AgX nanocomposites by a single mechanical treatment of powder precursors – AgNO3, NH4Х, NH4NO3 (diluent), commercial sulfur and DMSO in planetary ball mills with various milling tools. The method also includes washing the water-soluble components of mechanosynthesis.

On the territory of Southern Kazakhstan and its adjacent territory of Kyrgyzstan, there is a unique world-wide Betpakdala-Shu-Ili Province, where up to 15% of the world uranium reserves are concentrated. Technological work on the extraction and processing of uranium ores in these deposits began in the middle of the last century, while until the mid-80s mining was carried out by mining in mines and open pits, and from the mid-80s the method of sulfuric acid leaching was used.Object of this investigation is Kamyshanovskoe uranium deposit, which is located on the territory of Republic of Kyrgyzstan (about 22 km of its capital – Bishkek city). The natural gamma-emitted radionuclides were determined by gamma-spectrometry measurements (“Ortec” HPGe detector) in a core sample collected from the Kamyshanovskoe uranium peat deposit (0-37 cm depth). The results show U isotopes concentration peak at 12 cm, while the concentrations of its progenies are roughly constant down the profile. Thermo-gravimetry analysis (NETZSCH STA 449 F3A–0372–M) showed, the main part of potentially mobile phases (organic matter, clay and carbonates) was located at the surface.Solid speciation of uranium has been examined in peat samples collected at the Kamyshanovskoe deposit using sequential extraction. Sequential extraction was carried out using the protocol employed by A.Tessier and et al. In all filtrates natural uranium isotopes were measured by a high resolution alpha-spectrometer (“Alpha-analyst”, Canberra) after appropriate radiochemical preparation, consisting of extraction by 30% tributyl phosphate in toluene and electrodeposition on a steel disk with a mixture of 25% solution of ammonium chloride and saturated solution of ammonium acetate as electrolyte solution. Sequential extraction of peat samples clearly showed that most of uranium is in reversibly bound fractions obtainedby treatment with ammonium acetate, hydroxylamine with hydrochloric acid and distilled water, indicating high mobilization potential of uranium in this peat.