Vol 281 Iss. 1

Large-scale mineral mining, including critical minerals of oil, gas and coal, conditions withdrawal of vast land from the agricultural sector. The relevance of this problem is connected with prevention and elimination of disamenity of the subsoil use. It is necessary to determine a strategy of mining-disturbed land reclamation. The authors propose an integrated assessment of mining-disturbed land, which allows a comprehensive analysis of current condition of these man-made sites. The proposed procedure can serve as a framework for the development of recommendations on reclamation trend selection. It enables simultaneous sequential or parallel application of parameters and criteria from a compiled list. In the aggregate, these parameters and criteria describe features of man-made objects and their condition by quantitative and qualitative indicators determined during field study, field survey, lab-scale testing and office analysis. As a case study of the Novosibirsk Region, the necessity is demonstrated and a matrix is constructed for the mining-disturbed land assessment by the level and nature of the environmental impact, with the determination of boundaries and sizes of damage areas. The basis for ranking man-made objects was classification, typification and clustering of attributes which govern peculiarities of the external impacts on the environment (rocks, soil, artificial ground, surface water, groundwater, etc.). These attributes are characterized by parameters and quantitative indicators measured on various scales, which identify admissible and hyperadmissible environmental load. The proposed approach allows the integrated analysis of mining-disturbed land areas with a view to their further ranking by the environmental load, and for developing an expert system of the optimized selection of new application ranges for such land.

This study evaluates the effectiveness of industrial waste-based ameliorants for the phytoremediation of disturbed lands. To conduct an experiment surface soil samples characterized by an acidic pH, polymetallic contamination, and heavy physical and mechanical composition were collected from industrial wastelands in the Arctic region. Lime and industrial waste, such as smelter slag, pulp and paper mill (PPM) ash, and ash from the combustion of alternative fuels based on municipal solid waste (MSW), were used to neutralize these samples. To assess the efficiency of soil neutralization and detoxification following the application of various ameliorants, the pH of aqueous and salt extracts of the original soil and the soil mixtures, as well as the content of mobile and water-soluble forms of heavy metals, were determined. A pot experiment with Indian mustard (Brassica juncea) was conducted to comprehensively assess soil mixtures availability for phytoremediation, followed by an assessment of the biometric parameters of its aboveground biomass and a determination of the rate of heavy metal accumulation in plant shoots and roots. Brassica juncea demonstrated high tolerance to polymetallic contamination, with good germination and survival. Phytostabilization was also found to be the primary mechanism for reducing of soil pollution levels. The studied industrial wastes demonstrateda high potential for neutralizing acidic soils contaminated with heavy metals, compared to traditional ameliorants. A decrease in soil acidity and an improvement in their physical and mechanical properties and elemental composition were observed. To obtain productive soil mixtures, the application rates of the studied industrial wastes into acidic soils contaminated with heavy metals, as well as the duration of the treatment period, were experimentally determined: 16-33 g/kg of slag (8-week neutralization), 7-14 g/kg of MSW ash, and 20-39 g/kg of PPM ash (3-4 weeks neutralization). Future research will explore the synergistic effects of adding humic and fulvic acids into contaminated soils.

The scale of the environmental problem associated with the pollution of vast areas of industrial zones in the oil industry is significant and requires the use of new technological approaches in solving it. A developing technology in this field is the use of electrochemical remediation, i.e., the removal of petroleum products and associated aqueous contaminant solutions from environments using low-voltage electric currents. The advantage of this method is the purification of both the surface fertile soil and the deeper soil layers. A current trend in the deve-lopment of electrochemical remediation methods is their integration with other remediation technologies, which increases remediation efficiency through oxidation or pollutant extraction, as well as significantly reduces the time required for remediation. This work is devoted to combining the treatment of oil-contaminated soils with direct electric current with the adding of the oxidizing component, calcium peroxide. The creation of a reactive geochemical barrier made of calcium peroxide in the interelectrode zone is proposed. This barrier will act as an inductor of oxidative reactions that promote the gradual mineralization of petroleum hydrocarbons. The formation of a directed contaminated electrophoretic flow moving from the anode to the cathode through a layer of calcium peroxide is simulated under laboratory conditions, and the characteristics of the purification process are investigated. The dynamics of such important environmental parameters as voltage, acidity of the treated medium, volume of the generated electrophoretic flow and the content of petroleum products in the solid (soil) and liquid (water) phases after cleaning are studied.

The problem of waste disposal in the mining industry is urgent for the Arctic zone of Russia. Significant volumes of overburden rocks from the Kovdor phlogopite deposit, represented by poor vermiculite-sungulite ores, require the development of environmentally safe methods for their integration into economic circulation. The aim of the study is to assess the potential of vermiculite-serpentine concentrate (VSC) obtained from overburden rocks for the remediation of anthropogenically disturbed soils. The prospect of using VSC for improving soil properties is due to its favourable mineral composition (serpentine 30-35, vermiculite 28-31 wt.%). Laboratory experiments prepared mixtures of VSC with agrosoil (10-60 wt.%) and samples of urban soils from three cities in the Murmansk Region (Apatity, Kirovsk, and Monchegorsk) (20 wt.%), differing in the level of anthropogenic impact. The content of chemical elements in two mobile fractions was studied, phytotesting was carried out with French marigolds (Tagetes patula). VSC has an alkaline reaction (рН_Н2О 8.9) due to the presence of minerals in the composition capable of concentrating Ni; the gross content of this component is 730 mg/kg. It was found that the introduction of VSC increases the alkalinity of soil mixtures and the content of mobile forms of Ca and Mg. In slightly contaminated agrosoil, the content of mobile nickel when adding 10-50 % VSC increases from 1.5 to 2.5 mg/kg, with a content of more than 60 % it decreases below background values. Phytotesting showed that in the range of 10-60 % VSC, the root mass increased from 0.09-0.1 to 0.13-0.18 g/plant, there were no signs of phytotoxicity. For soils of Monchegorsk, characterized by a high level of anthropogenic contamination with nickel and copper, the introduction of concentrate, on the contrary, led to a steady decrease in the content of mobile forms of both metals. Vermiculite-serpentine concentrate can be recommended as a meliorant for soil remediation, poor in macroelements and contaminated with heavy metals.

The study presents analysis of the properties and parameters of waste from high-temperature processing of mineral raw materials – blast-furnace and steelmaking slags, dump slags from copper smelting and ferrochrome production, and incinerator slag. We perform a detailed analysis of the material composition of the studied materials, identify key resource and environmentally significant indicators of the chemical composition and physical properties of the waste, and adopt these as indicators of the resource and environmental potential of the slags. The paper considers approaches to grouping raw materials of industrial origin into categories with similar resource value and environmental hazard. As an alternative for classifying waste from high-temperature processes, we propose a cluster-based approach that enables building a categorization system for industrial raw materials according to their properties and limiting the number of sampling features while maintaining sufficient coverage of the classified materials. After standardizing and checking the multicollinearity of the selected indicators of the slags’ resource and environmental potential in the analysed dataset, the study finds that most indicators show low, absent, or random correlation. Using the Statistica software, we rank the studied materials via fuzzy clustering. Based on the resulting distribution, we define three cluster groups for treatment: resource-inert; resource-valuable with moderate environmental impact; and environmentally hazardous, requiring deep processing. The results show that granulated blast-furnace slags, lump blast-furnace slag, and ferrochrome production slag are suitable for manufacturing construction materials without preliminary dressing, provided the products meet environmental safety requirements. Steelmaking slags represent a resource-valuable material with moderate environmental impact and are suitable for producing metal concentrate. Copper-bearing slags and incinerator slags are environmentally hazardous and require deep processing with metal recovery, while tailings need stabilization and neutralization. The obtained results form the basis for further development of a methodology for comprehensive resource and environmental assessment of industrial mineral facilities, which is necessary for transitioning to closed-loop production cycles.