The increasing depletion of high-grade nickel sulfide deposits and the growing demand for nickel have intensified global interest in oxidized nickel ores (ONOs), particularly those located in Kazakhstan. This study presents a comprehensive review of the mineralogical and chemical characteristics of ONOs from the Shevchenkovskoye cobalt–nickel ore deposit and other Kazakhstan deposits, highlighting the challenges they pose for conventional beneficiation and metallurgical processing. Current industrial practices are analyzed, including pyrometallurgical, hydrometallurgical, and pyro-hydrometallurgical methods, with an emphasis on their efficiency, environmental impact, and economic feasibility. Special attention is given to the potential of hydro-catalytic leaching as a flexible, energy-efficient alternative for treating low-grade ONOs under atmospheric conditions. The results underscore the necessity of developing cost-effective and sustainable technologies tailored to the unique composition of Kazakhstani ONOs, particularly those rich in iron and magnesium. This work provides a strategic framework for future research and the industrial application of advanced leaching techniques to unlock the full potential of Kazakhstan’s nickel resources.

The article presents the results of comprehensive studies on the water quality of the Verkhnetobolsky and Karatomarsky reservoirs in Kazakhstan, focusing on heavy metals. Legal and regulatory documents on state environmental control of Kazakhstan waters were reviewed, along with normative documents and scientific recommendations on water quality and toxicology, including hygienic and MPC standards. State, interstate, and international requirements for water sampling and physico-chemical analysis were studied, including winter sampling methods under ice cover. Concentrations of metals and heavy elements were determined, and heavy metal indicators comply with hygienic safety standards for household, drinking, and cultural and general use. According to the Unified Classification System, the water quality for manganese and cadmium places the reservoirs in the fourth quality class, suitable only for irrigation and industrial use, requiring extensive treatment for household use. The Tobol River is generally classified as polluted. Most metals show small standard deviation and variation coefficients, indicating reservoir homogeneity. However, manganese, cadmium, zinc, copper, boron, and lead show high deviations, suggesting significant content differences due to element mobility and runoff from fields and tributaries. The results serve as reference information and methodological recommendations for assessing heavy metals and elements in freshwater reservoirs in temperate zones.

The article presents the results of comprehensive studies of the Verkhnetobol and Karatomar reservoirs in Kazakhstan, focusing on the content of pesticides, organochlorides, and organic toxicants such as phenol, petroleum products, and surfactants. Various organochlorine pesticides (alpha, beta, and gamma isomers of HCH, heptachlor, DDT, DDE, DDD, aldrin, hexachlorobenzene, lindane, 2,4-D) were analyzed, as well as levels of bromodichloromethane, dibromochloromethane, carbon tetrachloride, benz(a)pyrene, atrazine, simazine, phenol, formaldehyde, and surfactants. Laboratory studies were conducted according to state, interstate, and international regulations on water sampling, quality control, and toxicology of drinking and natural waters using physico-chemical methods. There were no exceedances of the MPC standards for the content of pesticides, organochlorides and organic toxicants. According to the requirements of the unified water quality classification system of the Republic of Kazakhstan, the content of the studied toxicants does not exceed the values of the indicators of the first and second classes of water quality. The waters of these water use classes are suitable for all categories of water use. In case of use for household and drinking purposes, simple water treatment methods are required. The legal and regulatory documents governing state environmental water control in Kazakhstan and scientific recommendations on the quality and toxicology of drinking and natural waters, including hygienic standards for economic, drinking, and cultural use, are considered. The results serve as reference data and methodological recommendations for assessing reservoirs in the temperate climatic zone for pesticides and organic toxicants.

The article presents the results of a comprehensive study aimed at investigating and implementing optimal sediment sampling methods under the harsh climatic conditions of Northern Kazakhstan. The research was conducted using the Verkhnetobolskoye and Karatomar Reservoirs as case studies—key hydraulic structures in the region that play a critical role in agriculture and water supply for the Kostanay Region. During winter fieldwork, various sampling techniques were tested, including gasoline-powered augers, tubular dredgers, and specialized containers for sample preservation. The stages of sample preparation, collection, transportation, and storage are described in detail in accordance with national and international standards. The study confirmed that bottom sediments serve not only as indicators of the ecological state of water bodies but also possess significant potential for secondary use in agriculture as organic fertilizers following appropriate treatment. The data obtained can be used for environmental monitoring, sanitary and hygienic assessments, and agroecological zoning of hydraulic facilities in the Kostanay Region. The methodological recommendations developed allow for the standardization of the sampling process and ensure the reliability of results in subsequent laboratory analyses.

The article presents the results of a comprehensive study of bottom sediments in the coastal zones of the Verkhnetobol and Karatomar reservoirs, located within the territory of the Republic of Kazakhstan. Sampling was carried out during the winter period under stable ice cover conditions, ensuring the representativeness of the data. Particular attention was paid to the analysis of potassium and phosphorus compounds-key macronutrients forming the mineral base of bottom sediments. A predominance of potassium oxides was established, which corresponds to previously published data on freshwater bodies. Within the framework of the study, rapid methods for analyzing the chemical composition of bottom sediments were tested and adapted using X-ray fluorescence spectroscopy, which proved effective under low-temperature conditions. The obtained results are consistent with the Guidelines for Monitoring and Assessment of Transboundary and International Lakes developed by the UNECE Working Group. The practical significance of the work lies in the creation of a scientifically grounded foundation for regular ecological monitoring of reservoirs used in agriculture. The presented data can serve as a reference for assessing the ecological state of bottom sediment systems in temperate flowing water bodies and contribute to the improvement and implementation of rapid analysis methods for solid-phase fractions of sediments using modern instrumental approaches.

Under conditions of increasing anthropogenic pressure and climate change, the rational management of soil resources is becoming a key factor in the sustainable agricultural development of the Republic of Kazakhstan. The purpose of this study is to analyze the composition and use of the land fund, the condition of agricultural lands, as well as the system of ecological regulation of chemical soil pollution. The tasks of the study included identifying regional features of land use, reviewing regulatory documents, analyzing current maximum permissible concentrations (MPC) of chemical substances in soils, and comparing the national regulatory framework with international standards. The methodological basis of the research consisted of comparative legal analysis and the synthesis of materials from official state sources. As a result, it was found that the majority of the country's agricultural lands (more than 70%) are occupied by pastures, while productive arable land is concentrated mainly in the northern regions. Such a distribution of land resources requires increased attention to their rational use and ecological safety. The regulatory framework of Kazakhstan covers only 7 chemical elements, which is significantly lower than the indicators of OECD and CIS countries. The study has scientific and practical significance, as it highlights the need to expand the list of regulated pollutants, taking into account the biogeochemical and agricultural characteristics of the regions. The findings can be used in the development of sustainable land use strategies, improvement of environmental policy, and in the practice of soil monitoring. The research contributes to the development of agroecological safety and the formation of a modern soil protection system in Kazakhstan.