The main results of research on the use of microwave radiation in wastewater treatment and treatment of their sedimentations, as well as water treatment waste, are presented. The thermal influence of microwaves on the water and sedimentations properties is considered. The experimental data obtained by foreign and domestic specialists for the following processes using microwaves are shown: degradation of organic substances, de-emulsification of oil-containing wastewater, removal of metals, disinfection, intensification of biogas yield, sediments pyrolysis, modification of the absorbents, intensification of compaction and dewatering of natural water treatment sedimentation. New microwave equipment for treatment the various wastes is described.

A method has been developed for the disposal of quarry drainage waters, which ensures that they are not discharged into an open reservoir and reduce their anthropogenic impact on the environment. The direction of drainage waters from the limestone quarry into the technological process of preparing the raw charge reduces the consumption of circulating soda solutions and ensures higher extraction of potassium sulfate from soda solutions. The average increase in the yield of potassium sulfate from an increase in the content of sulfates in the liquid phase of the raw nephelinelimestone-soda charge is 4.0 tons per day or 1,460 tons per year.

The results of studies of the physic-chemical and sorption properties of bleaching clay waste, the prospects for its use for the purification of polluted waters, as well as the possibility of subsequent disposal of used materials are presented. Using the method of low-temperature nitrogen adsorption-desorption, it was found that the studied bleaching clay waste has a specific surface area of 185.53 m²/g and has a mesoporous structure. The sorption properties of clay waste were studied and it was found that at a dosage of 1.5 g/dm³, the purification efficiency of the standard solutions containing Cu²⁺ ions with a concentration of 10 mg/dm³ is 96.7 %. It has been found that the maximum sorption capacity, determined under static conditions for clay fired at a temperature of 350 °C, is 0.41 mmol/g. The use of bleaching clay as filler pigments in the manufacture of paints and varnishes has been proposed and demonstrated.

A new promising direction for recycling the large-scale saponitecontaining waste from the JSC Severalmaz mining processing company is presented, the storage of which can negatively affect the ecological situation of the region and increases the risk of environmental pollution. It has been found that saponitecontaining material (SCM) in terms of MgO content can be considered as a medium-magnesian technogenic raw material for the production of magnesium cement. It has been shown that the main conditions for obtaining effective solutions based on saponite binder are as follows: the sealer is an aqueous solution of magnesium chloride at concentration of 8% and the water-to-solid ratio of 0.4. Cube samples were obtained based on a binder made from thermally modified saponite powder, taking into account the above factors, with a compressive strength of 5.78 MPa at density of 1600 kg/m³. It has been confirmed that the implementation of the above technological methods makes it possible to obtain structural thermal insulating concrete that meets the requirements of the relevant GOST.

The results of studies of the carbon sorbent adsorption properties by atomic absorption spectrometry are presented. Carbon sorbent was obtained by graphite nitrate cointercalation compound thermal expansion at 900 °C. It is shown that the Freundlich, Langmuir and Temkin equations adequately describe the adsorption of the studied metal ions by a carbon sorbent. The carbon sorbent after the adsorption of heavy metal ions was studied using energy-dispersive X-ray spectrometry and X-ray powder diffraction. The limit values were fixed for the adsorption capacity of the sorbent relative to Cu2+, Ni2+, Fe2+ as 0.94; 0.85 and 0.58 mmol/g sorbent, respectively. It was concluded that the conducted studies indicate the possibility of using such sorbent in processes of water purification from heavy metal ions.

The anti-erosion effect of an anionic polymer based on polyacetonitrile, "VPRG reagent (dry hepane)", has been studied when its solution was applied to the surface of agro-black earth, sand and clay in laboratory conditions. It has been found that the use of VPRG has a clearly positive effect only on the anti-erosion stability of agro-black earth; a weak positive effect was observed on clay, and an increase in the amount of washed-off material was noted on sand relative to the standard. It has been confirmed that an increase in the concentration of VPRG leads to an increase in the anti-erosion stability of agro-black earth, but reduces it for clay and sand relative to the standard. It has been concluded that the optimal dose of VPRG application corresponds to 106 kg/ha when dissolved in 10 m³ of water for agro-black earth and clay.

The results of a study of the contamination of a peat deposit of a representative oligotrophic bog complex (Primorsky district of the Arkhangelsk region) with persistent organic pollutants of polychlorobenzenes and pentachlorophenol are presented. Data on the quantitative content, composition and depth distribution of organochlorine pollutants have been obtained. The maximum amounts of polychlorobenzenes, pentachlorophenol and other chlorinated phenols in the upper 40-centimeter aerated layer of the peat deposit, the formation of which coincides with the period of “chlorine chemistry”, have been established. In addition, the presence of polychlorobenzenes and pentachlorophenol was revealed in all horizons of the upper meter layer of the peat deposit, which indicates their vertical migration in the peat body.

The paper considers the method for cleaning the municipal wastewater using LBR-technology (Laminar Biofilm Reactor) implemented by RDIEI with patented improvements to analogues. An assessment was made of the technology compliance with the requirements of the best available technologies set out in the information and technical reference book ITS 10-2015 "Wastewater treatment using centralized sewerage systems for settlements and urban districts".

An approach to a comprehensive assessment of the state of the natural environment near the objects of accumulated environmental harm (AEH) has been developed. It is concluded that the approach presented in the work makes it possible to rank the AEH objects as per a group of criteria using evaluation points and weighted ratios depending on the degree of harm (degree of pollution of the natural environment components), and also makes it possible to identify the objects where it is necessary to carry out measures for their liquidation as a matter of priority.

The possibility of using phytoremediant plants as a source of the most important elements of soil nutrition and to obtain fertilizers with a valuable composition of microelements has been considered. Data have been presented on the accumulation of potassium, calcium and ferrum in the tissues of phytoremediant plants Phragmites australis (Cav.) Trin. ex Steud., Typha angustifolia L., Typha latifolia L., used in the treatment of technogenically polluted wastewater from mining companies. It has been concluded that these plants have a high phytoextractive ability to extract elements of soil nutrition and can be used to create green fertilizers.

An assessment of the circulation of pesticides in the Saratov region was carried out. A list of pesticides that pose a potential hazard to public health as a result of chemical pollution of water bodies and aquatic organisms consumed by humans has been determined. It is proposed to use satellite images of the terrain located in the drainage basin area in order to justify the sampling points from surface water household supplies potentially contaminated with pesticides. The methodological aspects of the use of a multicomponent biotest system in establishing the toxicity of pesticides are considered. It is concluded that when arranging the biotesting to assess the toxicity of water and sediment samples containing pesticides in concentrations up to 10 MAC, it is recommended to use aquatic organisms with a minimally developed detoxification system.

International expertise in the neutralization, recycling and use of municipal wastewater sedimentation is reviewed. Information is provided on the main areas of neutralization and disposal of wastewater residues used in Asian and European countries. Thermal disinfection of non-flammable components, foreign, harmful and dangerous substances of sewage sediment is proposed, during which the biocoke is formed. The possibility of using the biocoke as a safe organic fertilizer was noted.