Examples of engineering solutions for wastewater treatment using flotation combines are considered. Technological schemes of wastewater treatment of various industries are given. Particular attention is paid to the description of flotation combines of the KBS series, in particular, the need to coordinate hydrodynamic regimes in various working areas of the flotation combine. It has been established that the use of flotation combines can significantly increase the efficiency of wastewater treatment at reduced material and energy costs.

The results of a research project on the creation and operation of quarry dump trucks using hybrid propulsion systems and batteries to reduce air pollutant emissions are presented.

The results of an experimental study of the regularities of the distribution of chlorine between solid and gaseous products during the thermal decomposition of a mixture of chlorine-containing medical waste during their pyrolysis and incineration are presented. It is shown that under thermal action on the chlorine-containing components of the mixture, chlorine is partially converted into gaseous products in the form of Hcl, and partially retained by the coke-ash residue. During pyrolysis, the bulk of chlorine remains in the solid phase. It is concluded that the retention of a significant proportion of chlorine by solid products of thermal decomposition significantly reduces the possibility of dioxin synthesis at the stage of flue gas cooling due to the low content of free chlorine in them.

The results of experimental studies aimed at developing a technology for producing belite sludge from high-alumina ash of coal-fired power plants are presented. The influence of various technological parameters on the process of obtaining the target product has been studied. The possibility of obtaining two grades of belite sludge is shown by the example of the ashes of thermal power plants in the Ural region.

Approaches to two main issues: assessment of the aggregative stability of colloidal systems in the light of the energy balance of the attraction and repulsion potentials of particles in aqueous suspensions for reuse in the enrichment of kimberlite ores, and the determination of rational conditions for its clarification by electrolyte coagulation are presented.

The influence of a pilot assessment based on the results of a change in the composition of wastewater on the quality of biological wastewater treatment when a sulfide alkali mixture is added to the feedstream of petrochemical enterprises is presented. It was found that the results of wastewater treatment at biological treatment plants are not affected by phenols in sulfide alkali wastewater. It was confirmed that activated sludge retains the ability to extract organic compounds without reference to the proportion of sulfide alkali effluents in the treated water.

The composition of samples based on krasno-yarsk clay with sludge and dearsenization cake of the Khovu-Aksy dump was considered. It was found that already at the stage of drying at room temperature there are changes in the structure and composition of the samples. There is a decrease in arsenic content in the materials of the samples, which further creates the prerequisites for their use in the production of ceramic products. Significant changes in the phase composition of the samples were found: they lack calcite, dolomite, a number of silicate and aluminosilicate structures, instead of them a new phase – albite – is formed. A significant amount of albite (up to 52 %) was observed in the samples fired at 850 °C.

A new method of processing experimental data and identifying parameters of flow structure by gas phase under conditions of filtration currents through layers of adsorbent granules in ecological mass exchange equipment is presented. Experimental data of gas phase velocity profiles and procedure of conducting experimental studies are presented. Basic design dependencies are given for determining parameters of flow structure by gas phase, based on treatment of experimental dependencies of non-uniformity of fields of flows of filtration currents through layers of adsorbents. An example is given of constructing C- and F-response curves that allow you to recognize models of flow structures by a continuous gas phase and increase the accuracy of mathematical modeling of mass exchange environmental systems.

The results of long term research on the influence of rocks stored in dumps during coal mining on the rate of soil processes during the regeneration of technogenic landscapes are presented. An approach to assess the lithogenic potential of soil formation as an integral indicator of the ability of technogenic substrates to ensure the formation of a climate-appropriate soil profile was developed and applied. It is shown that the main properties forming the potential are the density, rockiness and texture of rocks. The rockiness decreases in the upper part of the profile and the manifestation of signs of an eluvial process and the formation of a finely dispersed fraction during biochemical weathering was noted. The dependence of the processes of profile differentiation on the properties of the substrate and on hydrothermal conditions has been revealed. It is shown that the optimal conditions for the developing of the substrate by soil processes are formed on the dumps of coal and brown coal deposits in a humid climate. Further development of soil-forming processes limits by the increase in climate aridity and the degree of rock metamorphism.

A chemical composition assessment was performed on a industrial crop in Russia, Miscanthus × giganteus harvested in 2019–2021. It was found that, regardless of the habitat, after the second year of vegetation, Miscanthus × giganteus has a cellulose content exceeding 50 %, which makes it a cellulose-based material. The positive impact of Miscanthus × giganteus on the environment was demonstrated. Cultivation of Miscanthus × giganteus regulates CO₂ exchange, and its processing into cellulose, biofuels and high-tech products will reduce deforestation.

It was shown that under conditions of chronic exposure to oil fields, the bioremediation potential of autochthonous microbiocenosis, which is formed as a result of seral processes after the release of petroleum hydrocarbons into the environment, plays an important role. As a result of the study, it was found that in the bottom deposits of the Kamenka River (Kungursky district of the Perm Territory, Russia), located on the territory of the Kokuyskoye oil and gas field, bacteriocenosis decomposing oil hydrocarbons were formed. Communities include the main ecological and trophic groups of bacteria: heterotrophs – (1.4–2.4)×10⁷ CFU/g of bottom deposits, crude oil degraders – 5.0×10⁴–2.7×10⁷ CFU/g of bottom deposits, halophiles – 1.0×10⁶–1.3×10⁷ CFU/g of bottom deposits. It was showed that bacteriocenosis decompose alkanes and partially transform cyclanes and arenas, the main components of oil contamination in the study area. Thus, the possibility of restoration of the territory of chronic oil pollution as a result of realization of bioremediation potential of bacterial natural community was confirmed.

The parameters of the natural geochemical background of ecosystems of the Lunnoye deposit area were studied and the geoecological conditions of large and small watercourses of the Yukhukhta — Yukungra interfluve were assessed according to the state of the total pollution index of bottom sediments. 27 elements of the gross content were determined by the method of emission spectral analysis. The elements that determine the geochemical specificity of the territory were revealed: Bi, Li, Sn, Y, Be, Sc, K, Th, Cs and Ra. At the time of research, the state of the surface watercourses of the territory is assessed as moderately polluted. With further monitoring, special attention should be paid to the state of the river basin Yukhukhta and especially the dynamics of changes in the chemical composition of bottom sediments of the brook. Lunny and Mramorny. The elements K, Th, Cs, Ra, Be, Zn, Pb, As, Cr, and Ni are proposed as parameters for monitoring the geoecological state of bottom sediments.