Methods of utilization of process dust by returning it to the rotary kiln are considered. To reduce the emission of fine dust of electrostatic precipitators into the atmosphere and to increase the efficiency of its utilization it was proposed to remove it from the furnace turnover, not to mix it with the dust of the dust chamber, and then to dispose of it according to a separate scheme. It has been established that the return to the correction pool of the raw materials workshop of JSC RUSAL Achinsk of fine technological dust caught in the 1st, 2nd and 3rd electric field of the sintering furnace electrofilters will reduce the consumption of limestone to 530 thousand tons per year, while improving the overall environmental situation at the industrial enterprise.

Constructive schemes of noise mufflers of power plants developed by the authors of paper are described. A special set-up has been developed on the basis of a mobile compressor station, the main element of which is an internal combustion engine. Based on the results of tests of noise mufflers, it is concluded that the use of the proposed samples of mufflers can achieve a significant effect of reducing the noise of power plants of various types.

The results of the study of liquid products of hydrogenation processing of thermolysis oil obtained from a mixture of plastic waste are presented. It is established that as a result of hydrogenation processing of thermolysis oil in the conditions of the process of preparation of fuel for catalytic cracking and in the presence of catalysts of this process, hydrogenates with a high content of paraffins and low content of sulfur, nitrogen, condensed aromatic compounds and unsaturated hydrocarbons were obtained. Methods of processing these hydrogenates into motor fuels and feedstock for petrochemicals are proposed.

An analysis was made of the purification efficiency of three-component model solutions containing various amounts of iron, copper and nickel ions, and industrial wastewater containing the same amount of the above ions, using a sorbent obtained from sludge from a water treatment site. It has been established that in three-component model solutions, depending on the initial concentration, the efficiency of purification from iron ions is from 40 to 90 %, copper ions from 80 to 100 %, nickel ions from 90 to 100 %. In industrial wastewater, the efficiency of cleaning from iron ions is above 50 %, copper ions above 70 %, nickel ions from 60 to 80 %, depending on their initial concentration. It is shown that the use of this sorbent is promising for use in industrial enterprises both at the initial and final stages of wastewater treatment from iron, copper and nickel ions.

It has been established that in the process of joint heat treatment of a mixture of red mud – quartz-leucoxene concentrate, a change in the chemical composition occurs with the formation of pseudobrookite, which has an increased chemical activity compared to the original quartzleucoxene concentrate. It has been established that the product of the combined heat treatment of red mud and acid tar consists of a mixture of aluminum, iron, and titanium sulfates that are readily soluble in water. Calcium sulfate and silicon compounds have been isolated as insoluble impurities. It is confirmed that in order to achieve the maximum degree of interaction, the mixture of red mud and acid tar must be heated at a rate of no more than 1–2 °C/min until 550 °C and time 60 min.

Studies on the extraction of vanadium(V) oxide from spent vanadium catalysts by sulfate and soda-alkaline leaching were carried out at OJSC Maksam-Chirchik and OJSC AGMK. The extraction method of vanadium compounds from spent vanadium catalysts was presented. The feasibility of extracting vanadium from spent catalysts by sulfuric acid leaching followed by treatment with an ammonia solution was confirmed.

The analysis of the state of the MSW management system in St. Petersburg was carried out and its comparison with waste management systems in the EU countries was carried out. It is shown that the efficiency of the MSW management system in St. Petersburg is low. A methodology for assessing the economic and environmental efficiency of MSW management systems is proposed. It is shown that with the implementation of the adopted MSW management system in St. Petersburg, revenue for one year can be achieved in the amount of 1,590.788 million rubles.

The information about the concept of "ecological capacity of the territory", the history of the study of this area and an overview of the methods of its definition are provided.

The complex effect of tylosin and copper on the ecological state of the typical chernozem was estimated depending on the degree of change in its biological parameters. Indicators of the general contamination, the abundance of bacteria p. Azotobacter, catalase activity, length of shoots and roots of radish (Raphanus sativus L.) were studied. It was found that the degree of decrease in biological parameters depends on the concentration of antibiotics, the higher the concentration, the more pronounced the interaction with heavy metals and, therefore, the more significant the inhibitory effect on biological parameters.

Spatial features of the manifestation of climatic changes and the formation of extreme hydrometeorological processes that pose a threat to natural ecosystems and industrial infrastructure have been identified within the Leningrad Region. Databases of long-term data have been formed for all districts of the region regarding the variability of river flow and the occurrence of floods, the values of maximum daily precipitation and fluctuations in air temperature. The most vulnerable to climate change natural ecosystems and components of industrial infrastructure are substantiated.

A comprehensive chemicalanalytical investigation of the state of water, soil, bottom sediments, as well as technogenic soils of the former ash-disposal area in the water-shed area of the Red River in Khabarovsk was carried out. River water exceeds the MAC of soluble chemicals in terms of the content of suspended solids, phenols, oil products, as well as some heavy metals (iron, manganese, copper, nickel and zinc). Widespread contamination of bottom sediments and soil of the ash-disposal area with arsenic was revealed. The background rate of oil products was exceeded by 5.6 times in the soil of the water protection zone of the river. The conclusion was made about the genetic similarity in bottom sediments and soils which is due to the long-term impact of a complex of anthropogenic factors on the water-shed area of the Red River.

The paper presents the study results of the rock waste disposal area colonization with vegetation at the Kizelovsky coal deposit according to remote sensing data of the Earth and calculations of the vegetation index NDVI for the Perm Territory. It was determined that natural colonization of disturbed lands were taking place. An increase in the average values of vegetation for the studied dumps in the period 1986–2021 was revealed which is primarily due to the cessation of mining in the territory under consideration.