The process of CO₂ conversion into synthetic hydrocarbons including the stages of synthesis gas production on the catalyst NIAP 06-06 and hydrocarbon synthesis by the Fischer-Tropsch method on a bifunctional zeolite-containing catalyst has been investigated. Experimental studies of the process of catalytic conversion of CO₂ into synthesis gas were carried out in order to obtain gas with the ratio of H₂/CO close to the required ratio for Fischer-Tropsch synthesis. The possibility of obtaining gasoline and diesel fractions of hydrocarbons with a high content of isomeric structures that increase the performance characteristics of motor fuels has been shown. The yield of hydrocarbons C₅₊ with 1 m³ of initial CO₂ and H₂ at the synthesis temperature of 220 °C is found to be 44.5 g.

The results of obtaining and studying the properties of the composite for elimination of oil and petroleum products on water areas at low temperatures on the basis of oligomer obtained from urea resin and treated with polymer solution in organic solvent are presented. It is concluded that the proposed composite has a high degree of purification from oil and petroleum products, which does not change when the temperature drops to -40 °С.

The character of water chromaticity change in a water source, which is the main one for organizing water supply of a large urban agglomeration, is analyzed. It is shown that the correlation analysis characterizes the interrelationship between the coagulant dose and water chromaticity as noticeable (on the Cheddock scale), which predetermines the necessity to take into account water chromaticity as a parameter influencing the choice of coagulant dose. Variation series were constructed, empirical and theoretical functions of water chromaticity distribution by months were obtained. The possibility of modeling the reagent dose on the change of chromaticity taking into account specific conditions of practically constant influence of seasonal and random factors in the selected periods has been achieved. It is concluded that the chromaticity index makes a significant contribution to the value of the predicted value of coagulant dose.

Ecological and climatic features of solid municipal waste landfills in the north-western region of the Russian Federation are considered. It was noted that it is impossible to use the land for the intended purpose, stipulated by regulatory documents, immediately after completion of waste disposal. The incorrectness of the current regulatory documents in relation to the north-western region of Russia is emphasized. The expediency of reclamation in two stages is substantiated: at the first stage, the sanitary-hygienic direction is carried out – the creation of phytocenoses of anti-erosion and aesthetic purpose, at the second stage (after 2–3 decades and more) after assessment of the ecological situation in the landfill area the direction of reclamation is chosen and the target (economic) land use is established.

The possibility of using the electrodialysis for processing weak aluminate solutions (sludge water) for the purpose of their concentration and causticization is analyzed. For testing, a three-chamber electro-dialysis cell with heterogeneous cation exchange membranes MK-40 was used. The optimal operating parameters of the process were determined, as follows: pole-to-pole distance 3–4 cm and current density 2 A/dm² at the operating voltage on the cell of 20–26 V. Specific electricity consumption was established as 9.7–20.6 kWh/kg alkali, causticization efficiency 56.1–69.6%, alkali yield – 81%.

The results of the analysis of production of construction materials used for manufacturing hydrogen life cycle equipment are presented. The aspects of the life cycle of the main construction materials (steel, aluminum, nickel, copper, titanium, platinum, carbon plastics) used in hydrogen power engineering are identified. The results of the carbon footprint assessment for the production of these materials are presented depending on the production technologies, the energy source used and the secondary raw materials. It is established that in the development of a hydrogen gas turbine unit (GTU) the main contribution to carbon footprint is made by titanium (50,9 %) and nickel (37,6 %) alloys, in spite of the fact that more than 50 % of GTU consists of steel. It has been determined that in the production of solid-polymer fuel cells the main contribution to the carbon footprint is made by the smallest construction materials — platinum (78,1 %) and carbon plastics (15,7 %) due to the fact that they have the largest carbon footprint per kg of produced material.

Approaches to the utilization of lithium-ion batteries using hydrometallurgical and pyrometallurgical recycling methods are described, their advantages and disadvantages are considered. The global nature of the problem associated with high growth rates of lithium-ion batteries market and underdeveloped infrastructure for their utilization, which leads to environmental pollution by toxic components of batteries, is outlined. It is concluded that the development of new technical solutions in this area should be carried out with a balance between economic efficiency and compliance with environmental standards.

The results of monitoring studies of forest vegetation in the vicinity of a gypsum mining enterprise in the Arkhangelsk region are presented. The study of the most important morphometric parameters and vitality of plants of all main tiers of forest communities, as well as extra-tier biota, which included epiphytic and epixylous mosses and lichens, was carried out. It was shown that the composition and structure of the forest stand, herbaceous-shrub, moss-lichen tiers, as well as extra-tier biota did not undergo noticeable changes. It was noted that on the majority of sample plots, which are located in close proximity to the quarry boundary, there was an increase in the number of undergrowth, changes in the height and vitality of undergrowth bushes.

A comparative analysis of the actual greenhouse gas net runoff by the Russian land use sector has been carried out, which showed that depending on the methodologies and approaches used, as well as the type of initial data, information on the absorptive capacity can be aggregated into three groups: 1) studies based on process (inverse) modeling and VNIILM methodology; 2) studies with statistical net runoff modeling and approaches regulated by the IPCC on the basis of the state forest registry; 3) studies based on dynamic global vegetation models (DGVM) and ROBUL methodology, verified by the IPCC, but using as input data information from the state forest registry. An assumption is made that the existing official Russian ROBUL methodology, which coincides with the IPCC methodology, currently reflects a conservative estimate of the absorption capacity of the Russian land use sector and can be adjusted with a potential increase to 35-45% of the current values due to additional accounting of reserve forests in the calculations, as well as the results of the state forest inventory and a new state forest registry with a high degree of spatial resolution.

The morphological field description of soil profiles of the territory of Irkutsk region was carried out. Samples of soils, soil-forming rocks and vegetation were taken for further physical and chemical analyses to determine soil properties in the studied areas. Sample preparation of soils was carried out, phytotoxicity of soils was analyzed. Processing of the obtained data was carried out, as a result of which the percentage of germination of radish seeds in the upper horizons of soils of the key areas of Irkutsk and Angarsk cities was revealed, the length of shoots and the length of roots in the soils of the studied samples were measured, the index of soil toxicity was calculated.

Soil and aerotechnogenic migration of metals into woody plants (birch (Betula pendula) and balsam poplar (Populus balsamifera)) from technogenic zones of Tyumen was studied. Soil and tree leaves were sampled in the conditionally background area, near the airport, railway station and bus station, as well as in the area of enterprises: engine-building, oil refinery, battery and metallurgical plants. The content of acidsoluble form of metals in soils and leaves was determined by atomic emission spectroscopy. It was revealed that the accumulation of metals in soils from the anthropogenic zones of Tyumen compared to the control decreased in the series Pb>Cd>Cr>Cr>Ni>Zn>Cu>Fe>Co>Mn and reached 20 times. The accumulation of metals by birch leaves was found to decrease in the series Pb>Cr>Fe>Co>Cu>Cu>Ni>Zn>Mn>Cd, and by poplar leaves – Cr>Fe>Pb>Zn>Cd>Cu>Co>Mn>Ni. The accumulation and migration of metals in soils and trees from the urban environment were analyzed, which allowed us to identify Cd, Pb and Cr as metals with the “highest ecological risk”.