The process of washing plastic wastes, namely polyethylene film and subsequent treatment of washing water by flotation is considered . The technological scheme for wastewater treatment forming after washing plastic wastes was proposed. The effectiveness of the proposed scheme was tested in the laboratory. A four-chamber mechanical flotation machine for washing plastic waste has been developed, as well as a column flotation tank for post-treatment of greasy wastewater for use in industrial practice.

A comprehensive assessment of the energy and environmental efficiency of using plywood production waste as an energy fuel in steam watertube boilers units with a staged combustion scheme has been carried out. The components of the heat balance and emission of harmful substances are determined. The thermal engineering and granulometric characteristics, as well as the elemental composition of the combustible fuel and the formed focal residues, have been studied. Specific surfaces, porosity of entrainment particles were determined and their microscopic studies were performed. Specific surfaces, porosity of entrainment particles were determined and their microscopic studies were performed. It is concluded that it is necessary to modernize the ash cleaning system, and in the future to reconstruct boilers with the installation of tilt-pushing grids when implementing a layer-vortex combustion scheme.

The research results of the composition, properties and structural features of bottom ash waste from the Trans-Baikal Territory were presented to determine the possibility of their use in road construction. It was stated that bottom ash waste are non-frost heaving. The indicator of specific effective activity of natural radionuclides was determined SEA (²²⁶Ra, ²³²Th, ⁴⁰K) for samples of pulverized ash and ash and slag mixtures, which was less than 370 Bq/kg and indicated the possibility of their use in road construction without restrictions. The hydraulic properties of pulverized ash were identified that characterize them as latently active, and ash and slag mixtures as inert materials, which limits the possibility of their use as a separate binding agent. The conclusion was made about the need for an integrated approach to a targeted change in the physical and mechanical properties of ash and slag waste including the use of various mineral binders and stabilizing additives to include waste in the composition of road materials.

The results of experimental researches on the development of a technology for the treatment of acid industrial wastewater were presented. The impact of various technological parameters on the quality of treated water was studied. A two-stage technology was developed for the reagent neutralization of acidic wastes with toxic metal cations using technical calcium oxide (quicklime GOST 9179-77) with subsequent posttreatment of the residual sulfate ion with aluminum hydroxide. The optimal pH value for the neutralization of effluents at the first stage was determined, which ensures the conversion of toxic metal cations and anions into insoluble compounds. It was concluded that the treated water meets all quality targets for the main pollutants and can be used in circulation.

The results of identity composition of coloured technicl gypsum as a waste product of vanadium production at OAO "EVRAZ Vanadiy Tula" were presented. It was shown that gypsum is converted into anhydrite during heat treatment at 700 °C. It was proved that waste coloring is due to the presence of manganese hydroxide and vanadium oxide, their interaction during heat treatment forms manganese vanadate Mn₂V₂O₇ and changes the color tone of the product. As decorative building materials, it is recommended to use colored gypsum-containing waste and products of their heat treatment.

The effectiveness of washing agents on the basis of an aqueous suspension of bentonitic clay for cleaning model oil-contaminated sandy and rocky soils was evaluated. It iwas shown that environmentally friendly washing agents of humic- bentonitic compounds consisting of Lamco Clay, humic substances and a nonionic surfactant, showed the greatest efficiency. Washing agents of humic-bentonitic compounds are recommended for wide industrial use and as a gentle method of cleaning oil-contaminated sites and specifically in water and nature reserves.

The dynamics and efficiency of the use of frozen lignin-containing deposits of the pulp and paper industry and soils obtained on the basis thereof for the intensified reclamation succession of disturbed lands were analyzed. It was proved that over a four-year experimental period, an active process of self-overgrowing occurs with a change and an increase in the species diversity of phytocenoses with the stabilization of chemical and agrochemical composition of dumps of frozen lignin-containing sediments and soils as per the norme of GOST 54534-2011 “Resource saving. Sewage sludge. Requirements for disturbed lands for reclamation”.

The results of the assessment of soil contamination with potentially toxic elements (Sr, Pb, As, Zn, Ni, Co, Mn, Cr, V, Ti, Fe) in the zone of influence of potassium salt mining at the Verkhnekamskoye deposit (Perm region) are presented. A comparison is made with the clark, the regional background of the Perm region and the background of the natural region of the Southern Taiga. Data on the accumulation and dispersion of elements under the influence of the extraction of potassium salts in the humus and podzolic soil horizons were obtained, and geochemical series were compiled.

The vegetation index NDVI calculated and the dynamics of the obtained values were analyzed in the period from 2017 to 2021 for the administrative districts of St. Petersburg. Aspects of the application of the index under consideration for assessing and analyzing the dynamics of the state of urban green spaces were studied. The conclusion was made about the percentage trends in the state of vegetation cover in the context of city districts. Recommendations were provided to improve the reliability of the results for a possible analysis of the correlation of NDVI index values with other vegetation indicators, as well as to improve the quality of initial remote sensing data.

Research digest of sources of microplastics in the soil, analysis of impact factors, as well as environmental risks was completed. It was revealed that in recent years, many scientific publications have considered in detail the content, distribution characteristics and impact of microplastics on soils, but there is not enough data on the accumulation of microplastics in soil, and there is no single standard, sampling methods, extraction and devices for the quantitative determination of microplastics in soil. An analysis of the environmental risks associated with the accumulation of microplastics in the soil was carried out and showed a negative impact on animals, microorganisms and plants. It was concluded that there are no studies that reveal the details of the accumulation of microplastics in soil and their interaction with metals and organic pollutants.

An attempt is made to scientifically substantiate acceptable risk for its various types and types of human attitude to risk. A new original typology of a person's attitude to risk is proposed, including 11 main types, each of which is described and characterized in detail.