The efficiency of using Eichhornia crassipes as a biological sorbent for the removal of nutrients (nitrogen and phosphorus compounds) from water bodies, which induce eutrophication, was investigated. A comprehensive approach was applied – the study was conducted in three stages: laboratory experiment, field-scale experimental implementation in the water area of the Kozhukhovsky backwater of the Moskva River, and a subsequent analytical stage. A pronounced biosorption capacity of Eichhornia crassipes, particularly with respect to phosphates, was confirmed. It is concluded that the developed technological solutions (bioplato systems and boom barriers) have demonstrated their practical applicability under conditions of an urbanized water body.

An algorithm is proposed for studying the properties of acid mine waters and selecting an economically justified technology for purification of contaminated waters from ecotoxicants with involvement in recycling of accumulated environmental damage objects. The possibility of obtaining marketable products (ferrites and rare earth elements) with high consumer value is considered. A fragment of one of the variants of the technical structure, consisting of two sequential units ensuring purification of acid mine waters and concentration of rare earth elements from multicomponent solutions, was tested in a pilot setup.

An analysis of sources of formation of industrial zinc-containing wastes and various areas of application of zinc-containing raw materials is presented. Standardization of a zinc-containing by-product obtained after wastewater treatment of electrochemical galvanizing by dehydration was carried out. According to X-ray fluorescence analysis, the zinc content in the waste was established at 39.9±15% along with other elements. Possible ways of utilization of metallurgical sludge are considered; its high efficiency as a soil micronutrient fertilizer for agricultural crops is demonstrated. Optimal application rates of the zinc-containing by-product for these purposes were developed.

The possibility of creating porous composites based on wastes of metallurgical, pulp-and-paper, and agricultural production capable of effectively removing organic pollutants from wastewater, in particular tetracycline, was investigated. By pelletizing a charge based on this technogenic raw material and liquid glass used as a binder, experimental composite samples were obtained for sorption of tetracycline from solutions with different concentrations (10, 30, and 100 mg/dm³). A conclusion is made about the prospects of the developed sorbents formed from wastes of various industries for purification of aqueous solutions (wastewater).

An analysis of the potential for integration of biological and thermochemical conversion technologies for energy purposes was carried out. It is concluded that the new integrated biomass utilization technology contributes to expanding the range of processed raw materials and enables transition to a circular economy in which products of one process become raw materials for the next.

Technological parameters acting as selection factors of granular aerobic sludge in sequencing batch and continuous-flow reactors at different COD concentrations were analyzed. Key aspects of granulation are considered: substrate availability periodicity, hydrodynamic conditions in the treatment bioreactor, and directed gravitational selection of biomass. It is shown that the quantitative and qualitative composition of extracellular polymeric substances (EPS) serves as an indicator of granule stability and robustness. Important factors for the technology are identified: the presence of granule-forming substrates and the degree of their conversion into extracellular polymeric substances (EPS). Recent advances in the application of granular aerobic sludge in continuous-flow reactors are summarized, and the main barriers hindering their industrial implementation are identified.

The conditions for extracting valuable elements (recovery) from ash and slag waste are analysed. Methods of preliminary treatment of ash and slag wastes and chemical reactions affecting the quality of target products and efficiency of extraction of aluminum and silicon compounds are considered. It is noted that a key role in the transformations belongs to the thermodynamically stable mullite phase (aluminosilicate). Reactions of mullite destruction are systematized according to conditions and reagents (hydrometallurgy, fluorination, sintering). A conclusion was drawn regarding the feasibility of industrial implementation of the most effective roasting and hydrometallurgical approaches, as well as the directions for further research into the efficiency of chemical reagents.

The possibility of using wastes from processing of agricultural raw materials, wood, and wood biomass components as alternative oil sorbents for removal of oil films from water surface is shown. It was established that treatment of these sorbents with chemical reagents (on the example of rye straw) increases sorption capacity for hydrocarbons and reduces water absorption. Treatment of sorption materials based on various lignocellulosic raw materials with low-pressure high-frequency capacitive plasma in an argon–methane atmosphere was carried out. It is concluded that plasma modification of alternative oil sorbents (on the example of pine cones) increases maximum oil absorption and efficiency of oil film removal from water surface, while reducing water absorption during oil spill response.

A risk-based approach is considered for the analysis of adverse impacts on the natural environment of the northern and Arctic territories of the Krasnoyarsk Krai. Probabilistic graphical modeling based on Bayesian belief networks is used, allowing the formalization of cause-and-effect relationships between natural and technogenic factors, accounting for uncertainty in initial data, and enabling rapid updating of estimates under changing conditions. It is concluded that the proposed approach can be applied in territorial management systems, environmental planning, and in the development of measures aimed at reducing negative impacts on the ecosphere of northern and Arctic territories.

In the context of developing a closed-loop (circular) economy, this article analyzes the legal and regulatory documents governing the various stages of industrial waste management. The relationship between various types of waste management is examined, and the crucial role of recycling processes in achieving circular economy goals is demonstrated. It is demonstrated that the Russian Federation has adopted legal and regulatory documents that adequately describe the key stages of industrial waste management. Various options for obtaining secondary raw materials from waste are analyzed, and challenges arising during industrial waste disposal are identified.

An attempt is made to conduct a scientific analysis of facts related to Havana syndrome. It is hypothesized that this syndrome possesses properties of neurological disorders caused by the use of 5G networks, and therefore most likely has similar causes. Extremely negative effects of pulsed microwave emitters on human health are noted. In order to ensure environmental safety, a comprehensive approach is proposed, combining legislative, technological, and political measures for its subsequent inclusion in a new environmental security strategy of Russia.