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We have studied an Upper Devonian volcanoterrigenous carbonate complex in the north of the Kuznetsk trough. The northern part of the complex is subducted beneath the Meso-Cenozoic sedimentary cover of the West Siberian geosyneclise. Analysis of sedimentologic processes, the nature and specific composition of pyroclastic impurity, and the petrographic and chemical compositions of sedimentary rocks makes it possible to reconstruct the facies and geodynamic settings. It is shown that the fine-grained pyroclastic material is predominantly of andesite composition, whereas felsic and mafic volcanic components are subordinate. In the transition from the lower Frasnian to the Famennian, the content of felsic pyroclastic component increases. The geodynamic settings of the shelf and continental slope of the Siberian continent up to its base have been established. Facies analysis shows that the slope is west-facing (in the present-day coordinates). The deposits accumulated mainly in the basin; these are fine-grained terrigenous rocks, fine-grained limestones, slope landslide breccias and olistostromes, turbidites, and “conglomerate-like limestones” (paleoseismites). According to the geochemical data, the Late Devonian paleogeodynamic setting was stable and corresponded to the setting of an active continental margin. Arid to semihumid lithogenesis has been established. Marine sediments formed in an oxidizing environment with good water aeration.

Concepts of the stratigraphy of the coastal and shallow-sea sections of the uppermost Middle Jurassic and Lower Cretaceous, exposed on the right bank of the Anabar River, have radically changed many times. The performed study and analysis of the published data are aimed at refining the bio- and lithostratigraphic subdivision of the section, substantiating its stratigraphic completeness, and describing the identified stratigraphic units in detail. Comprehensive biostratigraphic studies of the uppermost Bathonian-lowermost Boreal Berriasian reveal a sequence of nine biostratigraphic units with dinocysts and palynoflora in the ranks of zones and local zones. Some of the palynological biostratigraphic units have been identified for the first time. Foraminifer assemblages of the boreal standard zones are recorded in the sections under study. The obtained biostratigraphic data and analysis of all known ammonite occurrences make it possible to demonstrate the stratigraphic continuity of the section in the Anabar River region, despite the reduced thickness of the stratigraphic units. The stratigraphic position of the boundary between the Sodiemykha and Buolkalakh formations is accurately defined. According to the interpretation proposed, the basal horizon of the Buolkalakh Formation is associated with a beginning of a new major sedimentation stage in the late Oxfordian-early Kimmeridgian, identified as the lower boundary of lithostratigraphic units of different ranks throughout the entire Arctic Region and partially in the Boreal Region. The lithogeochemical parameters of the studied formations are obtained for the first time. The content of C_org in the studied samples does not exceed its Clarke values, and the pyrolytic parameter T _max indicates that the organic matter is immature and the petroleum potential is low. The considered organic matter of the rocks is characterized by a heavy isotope composition of carbon, suggesting its mostly terrigenous genesis.

Structural and lithological comparison of intraformational plicative liquefaction deformations (convolutions) in Late Quaternary lacustrine complexes of the Baltic Shield (sediments of small glacial lakes) and the Tien Shan (sediments of a large stationary basin in the Issyk-Kul depression) is carried out in order to clarify their genesis. These regions have sharply different levels of seismotectonic activity, which makes it possible to most fully determine the role of a seismic factor in the formation of bedding disturbances. Convolutions in the Baltic Shield are represented by load casts, flame structures, pseudonodules, and regular folds with more pronounced anticlinal bends. It is shown that convolutions occur here only in the most liquefied soils (siltstones and fine-grained sands) with low cohesion and fluid permeability in the case of unstable (increased density and coarsening of the sediment from bottom to top) or neutral (homogeneous composition) stratification of weakly consolidated sediments, and the ratio of the widths of the synclinal and anticlinal parts of the folds ( K _syn) for these structures is 1.0-7.5. These signs point to the formation of disturbances because of a spontaneous instability or an instability initiated by weak mechanical influences in the sedimentary stratum under conditions of a normal vertical gradient of the sediment viscosity. Deformations in the second region are structures typical of the Baltic Shield, columnar structures of deep interpenetration of layers, diapirs, and clastic dikes. There are also flexural folds with K _syn ≈ 1, which formed at a higher degree of sediment consolidation than the actual liquefaction structures. The convolutions of the Issyk-Kul depression are developed not only in sand-silty sediments but also in relatively lowly liquefied soils (clay, gravel, and pebbles). These structures formed under both unstable and stable density stratification of the sediment (for example, clay-on-sand), and K _syn = 0.3-2.5. Thus, the formation of convolute structures in the Issyk-Kul depression is impossible without strong dynamic impacts on stratified sediments during their accumulation. The results obtained make it possible to substantiate the predominantly diagenetic (convective and landslide) genesis of convolutions in the lacustrine complexes of the Baltic Shield and the seismogenic genesis in the limnogenic deposits of the Tien Shan. A number of new criteria for identifying seismites are proposed, which determines the practical significance of the study.

Bottom sediments of lakes are regarded as one of the most informative continental facies used to reconstruct environmental changes in lake catchments. They usually contain a high-resolution and continuous record of geologic events, the knowledge of which is important for understanding the evolution of sedimentary processes and landscapes under the influence of climatic changes and the impact of short-lived catastrophic processes. The southwestern Baikal region (the Tunka rift and its East Sayan mountain framing) is replete with lakes of different geneses and morphologies. Recent fieldworks have allowed a multiproxy study of the lacustrine sediments of several lakes of the Oka and Tunka regions. The results demonstrate that there were no glaciers in the foothill plain of the Tunka rift valley earlier than 14,800 cal yr BP. On the Oka plateau, within the East Sayan high-mountain zone, deglaciation started somewhat earlier than 13,800 cal yr BP. The grain size, petromagnetic, and physical properties of the lacustrine sediments point to a general weak hydrodynamics throughout the 13,800 yr sedimentation history in Lake Khikushka. However, a gradual reduction in fine fractions from base to top of the lake section suggests a gradual drawdown of the water level following the change of the water source from glacial melt waters to atmospheric precipitation. Biogenic silt accumulation in Lake Khikushka started parallel with the onset of the Holocene ~11,700 yr BP, suggesting a quick response of the natural environment of the lake basin to major global climatic changes. The short-term episodes of enhanced hydrodynamics in Lake Khikushka ~9000, 8200, 6500, and 2000 yr BP confirm the high sensitivity of the lake geosystem to climatic changes, not only on a millennial but also on a shorter-time scale. The characteristics of the sediments of Lake Engarginskoe are evident of lacustrine-alluvial sedimentation in the reservoir in the Early and Middle Holocene. New data on the grain size and petromagnetic parameters of the lacustrine sediments from two lakes located within different climatic belts of East Sayan show their high potential for a wide range of paleoecological reconstructions.

Coal fires are a phenomenon that can be observed worldwide in areas where rocks containing coal seams are exposed and can pose major environmental threats. A coal fire can begin through spontaneous combustion when coals are exposed to dry and oxygen-rich near-surface conditions. Burning, depending on the temperature of heating, causes baking or even melting of the surrounding rocks and the formation of different types of combustion metamorphic rocks. In Northwestern China, coal fire occurrences are concentrated at the edges of the sedimentary basins or at the margins of orogenic belts, where coalrich units were exposed owing to the Indo-Eurasian collision. On the northern margin of the Tianshan range, evidence of coal fires is widespread in the Jurassic sedimentary units containing coal seams which outcrop along the Central Asian Orogenic Belt. In some cases, coal fires are active and can be linked to ongoing mining activity, but outcrops of combustion metamorphic rocks not associated with fires are also found and are indicative of past burning events. We examine combustion metamorphic rocks outcropping in the Toutunhe River valley (Liuhuangou area, Xinjiang, Northwestern China). Combustion metamorphic rocks in the study area were mapped and classified according to their morphological and mineralogical characteristics. Outcrops are exposed at various heights on the valley flanks, which are characterized by the presence of multiple levels of fluvial terraces. These terraces are indicative of the phases of erosion and deposition of the Toutunhe River and testify to tectonic uplift. The investigation of the stratigraphic and crosscutting relationship of combustion metamorphic rocks with terrace deposits and apatite fissiontrack dating made it possible to determine that at least four phases of coal fire activity occurred from late Miocene to Quaternary. The first and oldest burning phase dates back to 10 ± 1.3 Ma and terminated prior to 2-3 Ma; the second was active before ~550 ka; the third had terminated by ~140 ka; the fourth began later than ~5.7 ka. The relationships between combustion metamorphic rocks and fluvial terraces further suggest that coal fire ignition/extinction in the area since the Miocene have been linked to the interplay between the uplift of the Central Asian Orogenic Belt and the phases of fluvial erosion and deposition in interglacial periods.

This paper presents conventional and innovative technologies for wastewater and industrial solution purification from Ni²⁺ ions and accompanying non-ferrous metals. Several methods including sorption, extraction, flotation, chemical, electrochemical, membrane and microbiological separation of impurities from the liquid phase are introduced. Chemical methods involve nickel deposition in the form of insoluble compounds (hydroxide, carbonate, bicarbonate, sulphide, dimethylglyoximate), or metal powder by adding certain reagents. Carbon, aluminosilicate and some other inorganic materials in initial and pre-modified forms, as well as weakly acidic, strongly acidic, weakly basic, including chelate ion-exchange resins and fibres are used for sorption. The extraction of nickel ions from the liquid phase is carried out with the derivatives of organophosphorous, carboxylic acids, as well as with materials that combine the properties of solid sorbents and liquid extractants. Nanofiltration and reverse osmosis are the most relevant methods among the membrane purification methods. Foam separation of nickel ions during flotation is carried out using anionic and nonionic surfactants. Electrochemical methods include electrocoagulation, electroextraction, electroflotation, and electrodialysis using soluble and insoluble electrodes, as well as galvanic coagulation without connection to external power. Living and non-living biomass of some species of bacteria, fungi, algae, as well as their complex mixture in the form of activated sludge can be deployed for microbial extraction of nickel from aqueous media. The above purification methods are considered on the basis of case studies, both generally applicable and specific ones. Their advantages and disadvantages are briefly described.

The currently widespread methods of processing fuel oils obtained during the primary separation of oil are complex multistage processes, including preliminary vacuum distillation and subsequent cracking of the resulting vacuum gas oils, as well as the oxidation of residual tar into bitumens. For small-scale industries, such processes are costly and, in some cases, unprofitable. The article proposes a technology for thermolytic processing of fuel oil over a tin-lead melt in a semi-continuous reactor. The main advantages of the proposed technology are low process temperature and pressure close to atmospheric, as well as almost complete elimination of the formation of carbon deposits on reactor walls. The reported results describe experiments on thermal cracking of fuel oil carried out according to two kinds of destructive distillation: the classical version, and the version involving a tin-lead melt. It is shown that during destructive distillation on a tin-lead melt, deeper cracking occurs in comparison with classical destructive distillation. The content of gasoline fraction (IPB-180 °С) and diesel fraction (180-360 °С) in thermal gas oil obtained by means of classical destructive distillation is higher than in thermal gas oil obtained by destructive distillation on tin-lead melt, while the content of fractions boiling above 360 °C is lower. The group composition, density and dynamic viscosity of thermal gas oils differ insignificantly. For thermal gas oil obtained over a tin-lead melt, a slight decrease in sulphur content is observed. Analysis of thermal gas oils for tin and lead showed their absence. Thermal gas oils have a high content of aromatic compounds, which makes them a promising raw material for needle coke production. Multiple analysis of the tin-lead alloy after the completion of the process showed that the alloy was free from mechanical impurities present in the fuel oil, it also did not contain coke released during thermolysis, and the mass of the alloy remained constant, which means that in this case the alloy plays the role of an effective heat carrier, which makes it possible to deepen fuel oil thermolysis.

The methods of manufacturing the sintering additives to coal charges from the vacuum residues of visbreaking tar, one of the most widespread and large-tonnage products, are considered. The starting raw material was subjected to deep vacuum distillation on a laboratory unit and thermal oxidation in a batch reactor. Experimental samples of sintering additives were obtained, and the possibility to produce sintering additives of petroleum origin on this basis was investigated. The physicochemical characteristics of the obtained products were determined; the possibility of their transportation, crushing, mixing and use instead of sintering coal grades in coal coking charges was assessed. A comparison of the obtained sintering additives was carried out for different production methods: an increase in the extent of tar conversion in visbreaking, deep vacuum distillation of the visbreaking residue, and oxidation of the visbreaking vacuum residue. The possibility of the industrial production of sintering additives from visbreaking residues was evaluated on the basis of research results.

A method of aesthetic assessment of coastal landscapes surrounded by mountains at the regional level is suggested. Assessment and mapping of aesthetic resources of the territory are based on an understanding that viewing points and perceived landscape sceneries form an aesthetic system based on the geographical location. An aesthetic assessment was made by using geo-referenced landscape photographs taken during field investigations, and from the Panoramio web service database for 11 complex indicators characterizing the perception conditions of sceneries as well as their structure. The analysis of the landscape diversity of open and closed landscape scenes was carried out in a differentiated manner. The landscape diversity of open and semi-open scenes is determined by a combination of the ruggedness of relief and contrast of vegetation cover, while the differentiation of closed forest landscape scenes with a near perspective is based on the characteristics of the elements and components of the enclosing natural landscape (composition and density of the forest stand, the presence, abundance and height of the shrub layer, and the height and variety of ground cover). The assessment of complex indicators was carried out by using a three-dimensional model of the study area in Google Earth Pro, based on thematic layers imported from the Quantum GIS project (satellite images, digital elevation model SRTM, landscape typological and forest inventory maps, database of landscape photographs, etc.) with due regard for the obscuring role of vegetation cover. The contours of the landscape typological map at the level of groups of facies at a scale of 1:500 000 are used as mapping units. The score is assigned to the area from which the landscape is observed.

This study is concerned with the selection of optimal territories for installing solar photovoltaic power stations. The relevance of the research done is explained by the fact that electric energy generated by converting total solar radiation on a horizontal surface consisting of direct and diffuse components of PV cells has low output power; therefore, it is necessary to identify areas with a high power factor for more efficient power generation. However, due to the low efficiency of PV panels (14-18 %) and the low intensity of total solar radiation on a horizontal surface, a large installation space is required to achieve a certain power level. Due to the high cost of installing solar power plants, a comprehensive systematic assessment of the geographic factors of the region is required to select the most suitable location. Our selection of the Nakhchivan Autonomous Republic as the study area is explained by the fact that the radiation level is high compared to other regions of Azerbaijan (1220-1699 kW h/m² per year), and the number of hours of sunshine per year exceeds 2500. Since the creation of solar power plants in regions with high values of total radiation on a horizontal surface depends on technical, economic and environmental criteria, descriptive criteria are used to determine the optimal areas. The Analytical Process Hierarchy (AHP) model, based on Multi-Criteria Decision-Making (MCDM) methods, was used to identify suitable locations for solar power plants. In the first phase of the study, seven criteria were analyzed to determine suitable locations: total solar radiation on a horizontal surface, slope, land use, buffer distance from areas with high annual solar energy potential to residential areas, proximity to substations, motor roads, and power lines. In the second stage, the level of accessibility and suitability of areas within the framework of certain criteria was determined using the Weighted Overlay tool in Geographic Information Systems (GIS). In the second stage, using the weighted overlay tool in geographic information systems (GIS), the level of suitability of territories was determined according to certain criteria. As a result, of the study, it was concluded that 9,5 % (510 km²) of the land of the Nakhchivan Autonomous Republic has high suitability, 12 % (645 m²) - medium suitability, and 24 % (1290 km²) - low suitability for placing solar power plants. The remaining 54.5 % (2930 km²) of the region belongs to the territories that are not suitable for use due to low radiation, high slope, the presence of protected areas, settlements, agricultural areas and poorly developed infrastructure. Optimal locations cover mainly the southern and eastern parts of the region.