Manira Zhamanbayeva

The growing demand for sustainable and renewable materials has intensified interest in agro-industrial waste as an alternative source of cellulose. This review critically examines current approaches to cellulose production from major agro-industrial residues, including cereal straw, corn residues, rice waste, sugarcane bagasse, and oilseed by-products. Emphasis is placed on the relationship between feedstock composition and extraction efficiency, highlighting how lignin distribution, hemicellulose content, and mineral impurities influence pretreatment severity, cellulose yield, and process sustainability. The review systematically analyzes chemical, enzymatic, and mechanical processing routes, with particular attention being paid to pretreatment strategies, fibrillation intensity, and yield variability. Beyond cellulose recovery, key sustainability indicators—such as energy demand, water and chemical consumption, waste generation, and chemical recovery—are evaluated to provide a system-level perspective on process efficiency. The analysis demonstrates that cellulose yield alone is an insufficient criterion for sustainable process design and must be considered alongside environmental and techno-economic metrics. Advanced applications of agro-waste-derived cellulose are discussed using a feedstock-driven approach, showing that high functional performance can often be achieved with moderately processed cellulose tailored to specific end uses. Finally, the review addresses challenges related to feedstock heterogeneity, mineral management, standardization, and industrial scale-up, underscoring the importance of biorefinery integration, closed-loop resource management, and harmonized quality descriptors. These insights provide a foundation for the development of scalable and sustainable cellulose production pathways based on agro-industrial waste.

Floods increasingly threaten semiarid regions, yet their long-term soil ecological impacts remain underdocumented. This study quantifies the hydrologic change and flood-induced soil transformation on the Zhabay River floodplain (Akmola, Kazakhstan) using integrated field, laboratory, and remote sensing data. Gauge records (2012–2024) were analyzed; inundation was mapped from a 0.30 m DEM (Digital Elevation Model) merging SRTM (Shuttle Radar Topography Mission), Landsat 8/Sentinel 2, and UAV (Unmanned Aerial Vehicle) photogrammetry (NDWI (Normalized Difference Water Index) > 0.28) and validated with 54 in situ depths (MAE (Mean Absolute Error) 0.17 m). Soil samples collected before and after floods were analyzed for texture, bulk density, pH, Eh, macronutrients, and heavy metals. Annual maxima increased by 0.08 m yr⁻¹, while extreme floods became more frequent. Thresholds of ≥0.5 m depth and >7 days duration marked compaction onset, whereas >1 m and ≥12 days produced maximum organic carbon loss and Zn/Ni enrichment. The combination of high-resolution DEMs, ROC (Receiver Operating Characteristic) analysis, and soil microbial monitoring provides new operational indicators of soil degradation for Central Asian steppe floodplains. Findings contribute to SDG 13 (Climate Action) and SDG 15 (Life on Land) by linking flood resilience assessment with sustainable land-use planning.

Today, oil-based products are one of the most important resources for humanity, in particular, we have no doubt that gasoline, which is a source of fuel, is necessary, but the amount of emissions from this fuel source, if you look at the statistics, causes huge damage to the environment. In this regard, this article presents the results of studies conducted in the adjacent areas of Tarbagatai Munai LLP, located within the Tarbagatai and Zaisan districts of the East Kazakhstan region (East Kazakhstan region), show that the vast majority of harmful substances are released into the air in an amount of more than 1.5-2 times more than the maximum permissible concentrations established for populated areas (MPC). Based on the studies conducted at three sites, which differ in color, with a length of 4 km from the village of Karabulak, the following results were obtained, compared with the MPCo.s.: - "gray part", an increase in heavy metals, in particular (Pb) lead by 6 times, (Zn) was observed in the layer up to 0-5 cm zinc 5 times, (Co) cobalt 2 times, (As) arsenic 5 times, (Sr) strontium 2 times, petroleum products 47 times more. - the "black part", in a layer up to 5-60 cm in comparison with the background point, there was an increase in the content of heavy metals, in particular (Pb) lead by 3.7 times, (Zn) zinc by 1.5 times, (Co) cobalt by 1.8 times, (As) arsenic by 2.7 times, (Sr) strontium 1.9 times, 528 times more petroleum products. - the "yellow part", compared with the background point, there is an increase in heavy metals, in particular lead by more than 2 times, zinc by 1.2 times, cobalt by 1.6 times, arsenic by 3 times lower, strontium by 1.6 times lower. It was also found that petroleum products are 4.5 times higher in the upper part of the site, and 247 times higher in the lower part.. According to the chemical analysis, it was found that the soil of the deposit has a low humus content, is alkaline, weakly absorbent, and is saline with sulfates, chlorides, and bases. It has been established that the low humus content in the soil, low absorption capacity, carbonate content and salinity make the soil unstable to anthropogenic influences. keywords. Petroleum products, samples, environmentally harmful substances, solid particles, organized and unorganized emissions.

This paper investigates the influence of the technological parameters of detonation spraying on the phase composition of NiCr- and Al₂O₃-based coatings. It was determined that the phase composition of Al₂O₃ coatings during detonation spraying strongly depends on the barrel filling volume with the gas mixture. The acetylene–oxygen mixture, which is the most frequently used fuel in the detonation spraying of powder materials, was used as a fuel gas. To obtain a ceramic layer based on Al₂O₃, spraying was performed at an acetylene–oxygen O₂/C₂H₂ mixture ratio of 1.856; the volume of filling of the detonation gun barrel with an explosive gas mixture was 63%. To obtain a NiCr-based metallic layer, spraying was performed at the O₂/C₂H₂ ratio of 1.063; the volume of filling of the detonation gun barrel with an explosive gas mixture was 54%. Based on a study of the effect of the detonation spraying mode on the phase composition of NiCr and Al₂O₃ coatings, NiCr/NiCr-Al₂O₃/Al₂O₃-based multilayer coatings were obtained. Mixtures of NiCr/Al₂O₃ powders with different component ratios were used to obtain multilayer gradient coatings. The structural-phase composition, mechanical and tribological properties of multilayer gradient metal–ceramic coatings in which the content of the ceramic phase changes smoothly along the depth were experimentally investigated. Three-, five- and six-layer gradient coatings were obtained by alternating metallic (NiCr) and ceramic (Al₂O₃) layers. The phase composition of all coatings was found to correspond to the removal of information from a depth of 20–30 μm. It was determined that the five-layer gradient coating, consisting of the lower metal layer (NiCr), the upper ceramic layer (Al₂O₃) and the transition layer of the mechanical mixture of metal and ceramics, is characterized by significantly higher hardness (15.9 GPa), wear resistance and adhesion strength.

The structural-phase state and tribological characteristics of detonation coatings based on Ti–Si–C before and after pulsed-plasma exposure have been experimentally investigated. The authors of the research used a detonation set-up of CCDS2000 to obtain coatings. The modification of coating surfaces was carried out by a pulsed-plasma flow using the “Impulse-6” installation. The results of the research have shown that the modification of coatings surface by a pulsed-plasma effect causes an increase in the microhardness of the surface layer and in its wear resistance. It was determined that after such type of treatment, there is an increase in the content of the Ti₃SiC₂ phase. According to the results of XRD analysis, the improvement in the mechano-tribological properties of detonation spraying coatings of the Ti–Si–C system as a result of pulsed-plasma treatment is associated with an increase in the content of Ti₃SiC₂ phases in the coatings, as well as the formation of carbide and oxide phases on the surface layer.