In this work, we propose an alternative method for the utilization of sleepers, based on the use of a supercritical fluid extraction process. The preference for the implementation of a supercritical fluid extraction process for “extractable-extractant” systems exhibiting I–II types of phase behavior is given. On the example of supercritical fluid extraction of the impregnation material of spent wood railway sleepers, the efficiency of replacing the carbon dioxide participating as an extractant with a propane/butane mixture, which provide the desired change in the type of phase behavior in relation to such components of the impregnation material as phenol, anthracene and naphthalene is shown. The phase equilibria of thermodynamic systems involving carbon dioxide and a propane/butane mixture on the one hand and coal oil components such as phenol, anthracene, and naphthalene on the other are studied. The proposed method of processing spent railway sleepers allows you to select from it up to 97 % of the mass impregnation source material.

The results of the study on the purification of model water from petroleum products with the concentration of 15 to 100 mg/dm³ with the use of polyethylene foam (PE foam) and polypropylene foam (PP foam) polymer chips a well as the carbon ABZ sorbent as sorbents were presented. The sorption process was carried out under dynamic conditions. The model waters were purified with PE foam and PP foam polymer chips, the purification efficiency was up to 91%. To increase the purification efficiency of model waters from petroleum products, the model solutions were purified from petroleum products through a combined loading - PE foam chips and ABZ sorbent. It is shown that the use of a combined loading allows to reduce the concentration of petroleum products in waste water to standard values. The results of chromatography - mass spectrometric analysis confirm the high efficiency of waste water purification from petroleum products.

The urgent character of modernization of the drilling waste management technologies from the standpoint of improving the environmental safety of territories during the oil and gas field development and operation was substantiated. The analysis of the existing drilling waste management methods was conducted and the classification of drilling waste ponds was presented. A layer-by-layer radiation-chemical analysis of drilling cuttings formed at the cluster drilling well in the Western Siberia (on the example of the Kustovoy field of "LUKOIL-Western Siberia", LLC) was conducted. A method for handling drilling waste, which is realized through the dosage batching of domestic-made reagents into a device for drill cuttings unloading from a drilling rig. The minimization of the secondary contamination threat is ensured by a more thorough mixing of the reagents with the waste, an increase in the contact time and the reaction completeness. The technology presented in the project allows preventing the formation of drilling waste, increasing the utilization depth and improving the technical requirements for the quality of the materials obtained.

The long-term work experience of domestic specialists in the formation of coal fuel briquettes from carbon-containing waste of coal mining and coal benefication was generalized. Scientific approaches to the selection of coal materials, binding systems and special technological additives for the production of high-quality briquettes with various properties were presented. Organizational methods of solving this complicated ecological problem of the coal industry were formulated.

Compositions of artificial soil mixtures, including sand, clay, defecation mud, waste from wet magnetic separation and plant residues in different proportions have been developed. The components were preliminarily comminuted by an auger-drill in order to obtain a homogeneous composition with subsequent granulation, stored in natural conditions in the autumn-winter period, followed by filling in experimental vessels. No any phytotoxic effect for the initial components and for all analyzed samples of the obtained artificial soil mixtures was detected. The chemical composition and some physicochemical properties of artificial soil mixtures, such as density, deposit of moisture and humus content, were determined. It was shown that the samples of the obtained soil mixtures are close to the control (dark gray forest soil of the Belgorod region) and can be recommended for further use in creating cultural landscapes as a substitute for natural soil. The developed type of artificial soil mixtures is suitable for the cultivation of bulbous crops; moreover, a large increase in yield in comparison with the control for some compositions was found. Artificially created soil mixtures reduce the harmful effect on the environment by eliminating the storage of industrial waste such as iron ore and food, plant residues used in the composition of the artificial soil mixture. Artificial soil mixture can be used for remediation of technologically disrupted areas, which will allow restoring disturbed lands and reducing man-caused impact on solid waste landfills. The addition of industrial waste allows them to be re-involved in the technological cycle, which contributes to the development of low-waste and waste-free technologies. The results obtained indicate the possibility of using the studied soil mixtures for cultivation of the decorative bulbous plants. To recommend the developed compositions for the use in agriculture, it is necessary to assess the possibility of impurity translocation from soil samples into cultivated crops.

This article summarizes the results of a systematic review of the literature in one particular application area – the extraction of valuable elements (Fe, Al, Na, Ti) from red mud. The analysis showed that depending on the composition of the bauxite being processed and the instrumentaltechnological scheme for producing alumina, the content of iron oxide (Fe₂O₃) varies from 7 to 70 % by weight, aluminum oxide (Al₂O₃) – from 2 to 33 % by weight, titanium oxide (TiO₂) from 2.2 to 25 % wt., sodium oxide (Na₂O) up to 12.5 % wt. The achieved maximum percentage of iron extraction is 97.5 %, aluminum – 89.7 %, sodium – 96.4 %, titanium – 97 %. It was noted that all practical studies were carried out in laboratory conditions only. As the most effective, technological proposals have been allocated for complex processing of red mud, including processes of smelting reduction, magnetic separation, leaching with mineral (HCl, H₂SO₄, HNO₃) and organic (H₂C₂O₄) acids. In modern studies, it is proposed to use microwave, ultrasound, or plasma technologies in recycling. As a result of the work, a systematic table was proposed on methods for extracting Fe, Al, Na, Ti from red mud. Suggestions are made on the criteria of technology that would have environmental, energy and economic benefits.

In this work we carried out a numerical study of the gas flow through an open cell foam material with solid-state partitions and partitions containing micropores. The effect of a geometry change by adding micropores on the pressure drop, particle deposition efficiency, and filter quality factor is estimated. The results showed that the addition of micropores positively affects the filtering and hydrodynamic properties of the highly porous material for the same macroporosity of the medium, and for the case of total porosity of the medium, the material with micropores allows one to obtain an increased value of the deposition efficiency and filter quality factor for small particles.

The article provides an overview of the main existing methods for recycling rare earth metals from various types of waste. It was noted that the demand for rare-earth metals is increasing annually due to the growth of advanced technologies, mainly in the sectors of electronics, power engineering and photonics. It has been established that in countries producing final products of high processing, the chemical-technological processes of processing goods that have worked out their life cycle, and, first of all, fluorescent lamps, NdFeB magnets from electronic devices, and nickel-metal hydride (NiMeH) batteries containing rare earths are most quickly created. The most profitable and recycling option is the reuse of products containing rare-earth metals, however, such technologies are applicable for a narrow range of waste. Another important area of REM recycling is the processing of industrial waste. For countries with developed mining and chemical industries, mining processing technologies are attractive. It is shown that for Russia, more appropriate are schemes for the disposal of industrial waste, primarily waste from the production of apatite concentrate. The main problems of the development of REM recycling are identified: low content and dispersion of rare earths in waste; the presence of impurities that impede the extraction of valuable components and the toxicity of the used recycling schemes.

Тhe problems of valuation of ecosystem services in connection with the activation of economic activity of the Russian Federation in the Arctic zone are discussed. The types of negative impacts on the Arctic ecosystems and their assessment, investment risks existing in ecosystem services are considered. It is shown that the application of the methodology and apparatus of ecosystem services contributes to the adequate assessment and creation of a hierarchical classification of "usefulness" and "benefits" that society can get from the existence, use and nonuse of ecosystems. The concept of ecosystem services in relation to Arctic consists of three components: identification, monetization and ecological risk assessment. The example of the Arctic ecosystems shows that the susceptibility to assessment and the accuracy of the assessment can be quite different and is largely dependent on the type of service in the classification. The analysis of possible ecosystem services and their relationship with the quality of life of people in the Russian Arctic indicates significant investment risks.

The article continues a series of works devoted to two closely related aspects of water quality management in natural objects and water utilization – ensuring the reliability of water quality assessment and optimizing of its standardization. It was shown that the risks of false conclusions equally arise both when setting a standard – the maximum permissible concentration of pollutants in a water body, and when monitoring compliance with established requirements. It was demonstrated on specific examples that in both cases, depending on the method of the research error registration, opposite conclusions concerning the water quality can be obtained. To obtain scientifically based results, a risk-oriented approach, as well as the statistical methods that use loss functions in various modifications are required. A solution to the problem of assessing the reliability of determining the water quality class on the example of a typical challenge of industrial water use was provided, recommendations on the arbitration method in connection with the assessment of the correctness of the water attributing to restrictive standards were also proposed.

The expediency of implementing the principles of integrated water resources management in the Republic of Crimea is substantiated and proposals for their implementation are developed based on the analysis of world experience in organizing the water resources management process. The introduction of integrated water resources management in the Republic of Crimea will significantly improve the current water management situation: it will improve the environmental condition of water bodies; it will allow us to assess the volume of water resources that can be further involved in production; reduce the imbalance of interests of different groups of water users.