Permafrost Degradation Impact on Water Bodies in the Siberian Tundra (Samoylov and Kurungnakh Islands, Lena Delta) Using GIS Analysis of Remote Sensing Data and a Geochemical Approach

The article presents the geomorphological and geochemical investigation of the water bodies on the Samoylov and Kurunghnakh Islands, the Lena River delta. We used GIS-analyze analysis for identifying water body groups, depending on their geomorphological features. The studied water bodies are located on two principally different surfaces: the first and the third terraces of the Lena Delta. The water bodies occupy thermokarst hollow bottoms, which have various elevations above sea level. We identified the altitudes of the water bodies’ water surfaces by analysing with ArcticDEM. Additionally, we estimated the area of the water bodies by hand after mapping the borders of the water bodies in UAV imageries. We sampled the bottom sediments and water’s chemical composition. All water bodies were divided into groups: (1) small water bodies on the Yedoma upland surface; (2) water bodies in six thermokarst hollows; (3) water bodies on the first terrace. The water bodies bottom sediments on the Yedoma are depleted by the As and enriched by the Zn and Mo in comparison with sediments of other groups. The Rare Earth Elements concentrations in the bottom sediments of Yedoma water bodies and several water bodies on poorly degraded surfaces of the third terrace are lower than in other water bodies, except La

Engineering and Geophysical Research of the Tailing Dump under the Conditions of Growing Soils of the Base

The relevance of the work is due to the risks of an uncontrolled increase in circulating water leaks through sides and bed of the dam, caused by thawing of permafrost soils in the Far North. The main aim of the work is to scientifically substantiate a set of engineering measures to reduce filtration consumption and restore and maintain the waterproofing of the tailing dump. The object of the study was the tailing dump of the concentration plant, with adjoining filter walls. The tailing dump has been exploited since 1996; for the last 20 years, circulating water leaks into the shunting tank located below were recorded. Within the water area of the tailing dump and at the landfalls, geophysical surveys were carried out from ice by the TEM (transient electromagnetic) method. The obtained geoelectric sections made it possible to form a holistic view of the structure of the filtration zones in the right and left bank junctions. The data obtained will be used for planning anti-filtration arrangement

Permafrost Degradation Impact on Water Bodies in the Siberian Tundra (Samoylov and Kurungnakh Islands, Lena Delta) Using GIS Analysis of Remote Sensing Data and a Geochemical Approach

The article presents the geomorphological and geochemical investigation of the water bodies on the Samoylov and Kurunghnakh Islands, the Lena River delta. We used GIS-analyze analysis for identifying water body groups, depending on their geomorphological features. The studied water bodies are located on two principally different surfaces: the first and the third terraces of the Lena Delta. The water bodies occupy thermokarst hollow bottoms, which have various elevations above sea level. We identified the altitudes of the water bodies’ water surfaces by analysing with ArcticDEM. Additionally, we estimated the area of the water bodies by hand after mapping the borders of the water bodies in UAV imageries. We sampled the bottom sediments and water’s chemical composition. All water bodies were divided into groups: (1) small water bodies on the Yedoma upland surface; (2) water bodies in six thermokarst hollows; (3) water bodies on the first terrace. The water bodies bottom sediments on the Yedoma are depleted by the As and enriched by the Zn and Mo in comparison with sediments of other groups. The Rare Earth Elements concentrations in the bottom sediments of Yedoma water bodies and several water bodies on poorly degraded surfaces of the third terrace are lower than in other water bodies, except La

Geochemical features of migration flows in the impact zone of mining technogenesis (Mednogorsk)

The relevance of the research is caused by large-scale pollution of natural ponds and rivers which occurs at mine drainage, containing elevated concentration of metals, sulphates and other components, run into uncontaminated waters. Assessment of the degree of natural and technogenic waters balance to hydrogenic minerals is currently an urgent problem. Its solution allows describing the nature of the geochemical specifics of technogenic water, and the mechanisms of their formation, identifying the sources of chemical elements and processes of secondary mineral formation, forms of migration of toxic elements in the technogenic streams and their impact on the environment. The aim of the study is finding-out the regularities of secondary mineral formation in anthropogenic streams as major factor of removal of metals from solutions. The methods used in the study. Physical and chemical modeling of chemical species in solution was calculated using WATEQ4f code. At the same time the authors have calculated saturation indexes, indicating a potential undersaturation or supersaturation of solution with respect to various mineral phases. The results. The paper introduces the results of physico-chemical modeling of Mednogorsk geotechnical system with application of the WATEQ4f package. The authors calculated the chemical species of elements and saturation indexes with respect to a number of mineral phases. Various hydroxides and different types of jarosite, which are unstable in the mixing zone with Zhiriklya River and are able to dissolve, can be formed in water samples under study. These findings indicate the transition of goethite to ferrihydrite in the mixing zones of Green and Blue mine drainages and in Zhiriklya and Blyava rivers

Modeling the Process of Thawing of Tailings Dam Base Soils by Technological Waters

The storage of wastes from mining and mineral processing plants in the tailing dumps in regions with cold climates has a number of environmental consequences. Interactions of water with tailings in cold climates often lead to the thawing of permafrost soils, formation of technogenic thawing zones, and leakage of drainage waters. In the case of fault zones development in these areas, technogenic solutions are often filtered outside the tailing dump, promoting further development of filtration channels. In order to prevent leakage of solution from tailing dumps over time, it is necessary to determine the thawing zones and prevent the formation of filtration channels. In the case of the formation of a filtration channel, it is necessary to know what rate of rock thawing occurred near the formed filtration channel. In this study, for the tailing dump of a diamond mining factory, we calculated two exothermic effects: (1) due to physical heating of dump rock by filtering industrial water with temperatures from 2 to 15 °C through the rock; and (2) due to the chemical interaction of industrial water with the dam base rock. The amount of energy transferred by the water to the frozen and thawed rock over 10 years was calculated using thermophysical modeling and was 207.8 GJ and 8.39 GJ respectively. The amount of energy that the rock received during the ten-year period due to dissolution of the limestones and equilibration of solutions was calculated using thermodynamic modeling and was 0.37 GJ, which is 4.4% of the average amount of energy, expended on heating the thawed rock (8.39 GJ)

Geochemical modeling of heavy metals behavior in technogenic systems

Relevance. Improving the quality of forecasting pollutant migration requires understanding and reflection in models of hydrochemical processes, which determine the behavior of elements in a complex multicomponent, multiphase environment, their interaction with other components. In most cases, mine drainage is a complex mixture of substances experiencing mineral phase transitions with subsequent dissolution/sedimentation, which requires the use of numerical hydrogeochemical modeling. The aim of the research is a quantitative description of hydrogeochemical processes in interaction of neutral and slightly alkaline mine waters with a river. The methods of investigation included the analysis of water samples for general chemical (potentiometric and titrimetric methods) and elemental (ISP-AES) composition and calculation modeling of chemical forms of elements in solution and saturation indexes of mineral phases using the WATEQ4f program. The results of the study showed that, despite neutral and slightly alkaline pH values of mine drainages, heavy metals and sulfates can reach extreme values, and their mobile forms of migration can pose a real threat to aquatic ecosystems and landscapes. The main chemical forms of Zn, which is the main pollutant, are sulfate and aquatic complexes. After entering the river, zinc is mainly represented by aqua-ions and carbonate complexes. Iron at all sampling sites is represented exclusively by hydroxide complexes. Calculations of saturation indices relative to minerals have revealed that the streams are supersaturated with respect to Fe(OH)3 ferrithydrite, FeOOH goethite, BaSO4 barite, which are stable both in the mixing zone and in the river. Zinc, as the predominant pollutant, forms its own mineral phase, which in composition corresponds to willemite Zn2[SiO4]

Chemical Treatment of Highly Toxic Acid Mine Drainage at A Gold Mining Site in Southwestern Siberia, Russia

The critical environmental situation in the region of southwestern Siberia (Komsomolsk settlement, Kemerovo region) is the result of the intentional displacement of mine tailings with high sulfide concentrations. During storage, ponds of acidic water with incredibly high arsenic (up to 4 g/L) and metals formed on the tailings. The application of chemical methods to treat these extremely toxic waters is implemented: milk of lime Ca(OH)2, sodium sulfide Na2S, and sodium hydroxide NaOH. Field experiments were carried out by sequential adding pre-weighed reagents to the solutions with control of the physicochemical parameters and element concentrations for each solution/reagent ratio. In the experiment with Ca(OH)2, the pH increased to neutral values most slowly, which is contrary to the results from the experiment with NaOH. When neutralizing solutions with NaOH, arsenic-containing phases are formed most actively, arsenate chalcophyllite Cu18Al2(AsO4)4(SO4)3(OH)24·36H2O, a hydrated iron arsenate scorodite, kaatialaite FeAs3O9·8H2O and Mg(H2AsO4)2. A common specificity of the neutralization processes is the rapid precipitation of Fe hydroxides and gypsum, then the reverse release of pollutants under alkaline conditions. The chemistry of the processes is described using thermodynamic modeling. The main species of arsenic in the solutions are iron-arsenate complexes; at the end of the experiments with Ca(OH)2, Na2S, and NaOH, the main species of arsenic is CaAsO4−, the most toxic acid H3AsO3 and AsO43−, respectively. It is recommended that full-scale experiments should use NaOH in the first stages and then Ca(OH)2 for the subsequent neutralization