Polymer cryogels are very promising for producing functional materials. Their porous structure makes them indispensable for some areas of medicine, catalysis, and biotechnology. In this review we focused on methods for producing cryogels based on biopolymers, interpolyelectrolyte complexes of biopolymers, and composite cryogels based on them. First, the properties of cryogels and brief theoretical information about the production of cryogels based on biopolymers were considered. The second section summarizes the latest advances in the production of cryogels based on complexes of biopolymers and composite cryogels. The features of the synthesis and the factors affecting the final properties of materials were considered. In the final part the fields of application of cryogels of the considered types in biotechnology, catalysis and medicine were studied in detail. In biotechnology cryogels are used to immobilize molecules and cells, as a basis for cell growth, and as chromatographic materials for cell separation. In catalysis cryogels are used as a matrix for the immobilization of metal nanoparticles, as well as for the immobilization of enzymes. Biocompatible cryogels and their composites are widely used in medicine for bone and cartilage tissue regeneration, drug delivery, providing a long-term profile of drug release in the body.

In recent years, interest in natural therapeutic mud has been growing all over the world. This natural product has a positive therapeutic effect on the skin and has fewer side effects on the human body. There are more than 40 thousand salt lakes in Kazakhstan. Most of them have natural mud sources, the potential of which has not yet been fully explored. The review presents an analysis of the available information on the physical and chemical properties of the main sources of natural mud from salt lakes in Kazakhstan and Kazakh sanatoriums that use natural mud in the treatment. All available publications, presenting the systematic studies, were used for data analysis. A comparative analysis of the mineralization of water, brine, and silt in one reservoir shows that the mineralization of water is not always the least. The available data indicate a point and partial nature of peloid studies, e.g., inorganic composition of natural muds from Western and Southern Kazakhstan is well described in the literature. In turn, there is a lack of these data from Northern and Eastern Kazakhstan. Studies of peloids in these regions seem to be a promising direction of the future research for both local and world scientists. What is more, there is also a big gap in the analysis of organic matter of muds from the Kazakh lakes. Comparing the state of the art, i.e., the studies from other parts of Asia and Europe, the identification of the organic part of muds is another desirable direction as a potential source of biologically active compounds of natural origin.

The results of the mechanochemical activation of coal from the Shubarkol deposit in an impactgrinding mill and under exposure to γ-radiation with an electron beam on a LU-6 electron accelerator are...

The purpose of this article is to study the sorption of heavy metals by humic acids of light and dark chestnut soil. The objects of research are the samples of dark and light chestnut soils, selected from an ecologically clean area of East Kazakhstan. Humic acids (HA) were separated from the soil at different pH values. At the same time the yield of HA was 0.075% from dark chestnut soil at pH 1.0, and it was 0.017% from light chestnut at pH=7.0. Further, the dependence of the sorption degree on the medium acidity was established. It was found that zinc and cadmium are better sorbed in a strongly acidic medium (рН1.0; 84.14%), while lead is preferably sorbed at pH 6.0, and the degree of its sorption is higher (93.54%). It was established that metals have a mutual effect, suppressing or enhancing the sorption of each other in bi- and polyelement variants. It was shown that cadmium significantly suppresses lead sorption in neutral media. Zinc more often increases the sorption of both cadmium and lead by 3 times. It was concluded that the binding of heavy metal ions by the organic fraction of the soil occurs due to the complexation with humic acids.

This study investigates ceramic bricks produced by partially replacing clay with Pb–Zn metallurgical residues (lead furnace dust and cyclone dust), fly ash, and carbonaceous additives. The novelty lies in the integrated multi-waste formulation and the combined FTIR–TGA–XRD analytical approach used to elucidate phase-formation mechanisms. The results show that firing promotes the development of quartz, mullite, iron oxides, and an extensive Fe–Pb–Zn–Si–O amorphous network, while higher residue contents enhance amorphization and suppress mullite crystallization. These microstructural changes correlate with reduced compressive strength (1.6–3.1 MPa) and high water absorption (32–36%), although all samples completed 15 freeze–thaw cycles. Heavy-metal leaching assessed by atomic absorption spectroscopy (AAS) revealed very low Pb (0.08–0.20 mg/L) and Zn (0.25–0.45 mg/L) release, well below international safety limits, demonstrating effective immobilization of hazardous ions within the glassy matrix. Overall, the study provides new insight into multi-waste interactions during sintering and confirms that controlled residue incorporation enables environmentally safe, non-load-bearing ceramic materials with reduced clay consumption.