Composition Of Natural Waters Research Articles

Chemical composition of natural waters from the Urov endemic area

Owing to the importance of drinking water in human nutrition, in this study, we performed a comparative analysis of the chemical composition of drinking water from settlements endemic to Kashin–Beck disease and from territories that are not endemic to Kashin–Beck disease. Our analysis showed that all drinking water samples were weakly alkaline and had a hydrocarbonate–calcium–magnesium composition. There were no considerable differences in mineralization, pH, or concentrations of Mg, Si, F, Se Zn, K, and Na. All waters had weak hardness specific for the waters from the northern territories. The mineral waters from the Urov biogeochemical subregion of the biosphere have elevated concentrations of Ca, Mg, Sr, Si, and Li and lower concentrations of I, Se, and Cu. The maximum Sr content was found in mineral water from the Bazanovo village, i.e., 20 mg/L, with a Ca/Sr ratio of 8 units. Owing to the inconsistency of data on the chemical composition of drinking water from the territories endemic for Kashin–Beck disease, we suggest an indirect role of biogeochemical factors in the disease pathogenesis. Previous pathologies may be important, which have arisen because of hypothermia, common cold, hormonal imbalance, and alimentary factors.

First data on the chemical composition of natural waters at the gold deposit “Novye Peski” (South Karelia, Russia)

Actual analytical methods make it possible to precisely determine a of chemical elements contained in water, including for the purpose of assessing the ecological state of the environment in connection with mining activities. The object of this research is the natural waters of the gold deposit “Novye Peski” located in the Pryazhinsky region (Republic of Karelia, Russia). Analytical data indicate that the geochemical background of the region is exceeded for most of the chemical elements. Research results indicate that the geochemical background of the region is exceeded for most of the considered chemical elements and ions, which can be divided into three groups: 1) the highest concentrations were determined in quarry water (Zn, As, Mo, U, Ni, Cu, Sr, Li, B, as well as Ca 2-); 2) the content is at the same level in all and other cations, HCO3samples (Al, Si, V, Ti, Ba); 3) the highest content in stream and tailing pond (Fe, Mn). We assume that the main factor influencing the behavior of elements of the first group is mining, and for the third is the presence of dissolved organic matter high content with the formation of metal-organic species in water.

Magnetic Modification of Ion Exchange Processes

Today, the ion exchange method is widely used in water treatment systems. Ion exchange systems are used to correct the mineral composition of water to the required standards; wastewater treatment; desalination and softening of natural waters. To present day, there are technical solutions to improve the process of water purification, treatment, softening and demineralization. They include: improvement of physical and chemical conditions; intensification of the ion exchange process; use of new ion exchange materials; modification of ion exchange resins; combination with other water treatment methods; modernization of equipment and designs of ion exchange devices. In order to improve the flow conditions and reduce the burden on the environment, it is promising to implement technologies aimed at intensifying the ion exchange process by activating the components of the process. The paper investigates the effect of magnetic modification on the intensification of ion exchange processes during the adjustment of the mineral composition of natural waters. The obtained results demonstrate the influence of the magnetic field on the ion exchange process.

Развитие методики расчёта нормативов допустимого сброса жидких производственных отходов с учётом региональных особенностей водных объектов

The problem of regulating the discharge of liquid wastes into water bodies is the most urgent task and is carried out on the basis of establishing standards of permissible discharge (SPD). Many authors note that the key problem of setting the SPD is the use of maximum allowable concentrations (MAC) as threshold values, determined without taking into account regional peculiarities of formation of natural water composition and its ability to dilute wastewater. We have proposed the development of the methodology for calculating SPD, based on the condition that ensuring the disposal of liquid wastes at the level of permissible discharge standards will not lead to a change in the water quality class determined using the specific combinatorial index of water pollution (SCIWP). In the previous publication we have substantiated territorial threshold concentrations (TTC) based on the analysis of long-term data sets of hydrochemical observations, which allow us to take into account regional features of the geochemical background of water bodies, including the content of substances of dual genesis. They also implicitly allow taking into account hydrological and hydrochemical factors that ensure the ability of natural waters to dilute liquid waste effluents. The obtained TTCs are proposed to be used for calculation of permissible concentrations of substances in wastewater instead of MAC. SPD is established by cyclic iteration of TTC values by 10%, with parallel calculation of SCIWP, until the index is transferred to another water quality class. This paper presents the results of approbation of the proposed development of the methodology of SPD calculation for liquid waste from Оpen JSC “Kazan Synthetic Rubber Plant” discharged into the Volga River. The obtained calculation results make more stringent requirements to the value of SPD for substances mainly of anthropogenic origin. For some substances of dual genesis, the value of SPD was higher, which allows us to make more adequate requirements to water users for treatment of sewage effluents.

ANALYSIS OF HYDROGEOLOGICAL CONDITIONS OF OCCURRENCE AND QUALITY OF GROUNDWATER IN THE TERRITORY OF KEZ SETTLEMENT OF THE UDMURT REPUBLIC

In the village of Kez of the Udmurt Republic, the drinking water supply is carried out at the expense of groundwater. The quality of groundwater does not fully comply with hygienic standards. Formation of the chemical composition of natural waters in the study area is determined mainly by natural factors, namely the hydrogeological conditions of their occurrence. Anthropogenic factors in the study area do not significantly affect the quality of groundwater. Almost everywhere there are waters with excess of boron standards, as well as with an increased level of mineralization. No excess of MPC for nitrates, nitrites and ammonium was recorded. To provide the population with high-quality drinking water, it is proposed to search for other underground sources of water supply, the water from which will comply with hygienic standards. The analysis of hydrogeological data and the conditions of occurrence of aquifers in the study area showed that the Slobodskoy complex and the roof of the Verkhneurzhum formations are the most suitable for operation. Drilling deeper wells will lead to deterioration of water quality by underlying alkaline waters, which, due to their alkalinity, will more actively dissolve boron contained in rocks. It was also revealed that drilling wells for drinking needs in deep cuts of river valleys is impractical due to the fact that in this case highly mineralized waters are opened. Prospecting works should be carried out within the framework of hydrogeological studies of the territory and regional monitoring of groundwater.

ON THE COMPARATIVE ANALYSIS OF THE COMPOSITION OF LYSIMETRIC WATER UNDER CONDITIONS OF DIFFERENT SOIL TREATMENT AND UNDER PHYTOCENOSES

A comparative analysis of the composition of lysimetric waters for 2021–2022 was carried out. for two groups of stationary soil lysimeters in the city. The first group of lysimeters is formed by the system: fallow — grass phytocenosis — overgrown fallow — spruce forest — mixed and broadleaved plantation, developing on the same type of mantle loam. The second group of lysimeters represents soils with different types of tillage: conventional plowing, extradeep planting according to Bushinsky, plowing according to Mosolov, deep plowing according to Kachinsky.For both groups, the same type of migration of components is shown, in which the most migrating elements are carbon, mono- and divalent cations, and chloride ion, with minimal migration of iron, manganese, and aluminum.In the group of lysimeters under various types of vegetation, as the tree canopy develops and, accordingly, the intensity of the biological cycle increases in migrating waters, the concentration of such important biophilic elements as magnesium, calcium, potassium, and carbon increases significantly, and among anions, chloride and sulfate ions. This determines, within the framework of the cluster analysis, two different subgroups in terms of the composition of natural waters: the first one is formed by the fallow-grass phytocenosis — overgrown fallow system, and the second one combines tree plantations.In the group of lysimeters with different tillage, a cluster characterizes the composition of water in lysimeters with reclamation plowing according to Mosolov and deep plowing according to Kachinsky. At the same time, individual aggregates form lysimeters with conventional plowing and ultradeep planting according to Bushinsky. This is explained by the fact that in this group of lysimeters, the initially created soil profile design is transformed, which is characterized by the placement of eluvial and illuvial soil horizons in various combinations and at different depths depending on the type of plowing.

Composition, Distribution, and Attribution of Hydrochemistry in Drainage Systems in the North of Tianshan Mountains, China

The characteristics and sources of the hydrochemical composition of natural water are mainly influenced and limited at the basin scale by what factors, this has become a focal issue of environmental change in the middle latitude areas and even globally. In this study, three large drainage systems (Junggar, Yili, and Erlqis) in the north of the Tianshan Mountains were selected to study the hydrochemistry of different river basins and understand the relevant causes and attributions of different water bodies in arid environments in the Central Asian Orogenic Belt (CAOB). Natural water samples from the three drainage systems and their hydrochemical data, combined with literature data of the north and south Tianshan Mountains and surrounding areas, were systematically collected and comprehensively compared with other higher, middle, and low latitude watersheds with different climate conditions. The results show that the total dissolved solid concentrations in the CAOB drainage systems are generally higher than those of rivers in Chinese monsoon and humid regions, and also higher than the world average level. The relative concentrations of different ions are similar to those of rivers in the monsoon region of eastern China and most rivers in the world dominated by carbonate weathering. The ionic compositions of surface water bodies from different sub-basins in the study area are distributed near the Ca apex in the piper diagram, while those of phreatic and confined groundwater samples tend to the Na apex. The compositional differences in the anions are not like those in the cations, rarely distinguishable for these different water types. In a sub-drainage basin scale from I to VIII sub-basins in the study area, major ion concentrations and distributions in these basins are evidently heterogeneous. Almost all the cation and anion concentrations span > 1 order of magnitude, especially sodium and chlorine; however, the calcium and alkalinity concentrations and distributions are relatively homogeneous for some basins in the Junggar and Yili drainage systems. The relative homogeneity between anions and the relative heterogeneity between cations can be recognized in the ion chemistry of natural water samples between different types, indicating that the composition and distribution of cations in water is more conducive than those of anions to identifying the differences and commonalities between different regions. Atmospheric precipitation plays a key role on the hydrogeochemical process in the north of the Tianshan Mountains, and the elevation differentiation of chemical weathering and ion concentrations are closely related to it. The positive correlation between total solute flux and runoff cannot be explained by the dilution effect, indicating that hydroclimatic factors such as runoff and aridity have a strong effect in limiting the hydrochemistry of natural water bodies in the study area.

Isotope Composition of Natural Water in Lake Onega Basin

In 2009–2018, the isotopic composition of oxygen and hydrogen in the atmospheric precipitation, groundwater and river and lake water of Lake Onega basin was studied. The weighted annual isotope composition of precipitation at Petrozavodsk was δ18O = −11.7‰ and δ2H = −84‰ and varied from −30.9 to −4.1‰ for δ18O and from −23 to −22‰ for δ2H. The isotopic composition of the water in Lake Onega was relatively uniform from −11.5 to −9.3‰ for δ18O and from −85 to −71‰ for δ2H. In the bays, the isotopic composition of the water varied more substantially than in the central part of the lake due to the river runoff during springtime flooding. In late summer, the concentrations of deuterium and oxygen-18 increased in the lake water, and figurative points on the δ2H vs. δ18O diagram shifted above the meteoric line. The absorption of the isotopically heavy summer precipitation and disequilibrium isotope fractionation during evaporation led to the enrichment of the lake water by heavy isotopes. Experiments were conducted to estimate the evaporation influence on the isotope enrichment of the residual water, and a comparison of the obtained isotope data with the experimental function showed that commonly, about 4% and up to 12% of water was lost during the spring and summer, respectively. In the water of the tributaries, the abundance of the deuterium and oxygen-18 varied in a wider scale than in the lakes, from −14.4 to −9.1‰ for δ18O and from −102 to −73‰ for δ2H. An evaporation loss of up to 35% was found for the rivers in late summer, and this value was proportional to the area of lakes and wetlands in the elementary watershed. The initial isotope composition of the water in the tributaries prior to evaporation was estimated to be δ18O ≈ −14.1‰ and δ2H ≈ −103‰ on average and crossed the approximation and meteoric lines. This estimation was close to the average composition of the groundwater, i.e., δ18O ≈ −13.4‰ and δ2H ≈ −94‰ on the Lake Onega catchment. The slightly increased isotope depletion of the calculated composition in the initial river water in comparison with the groundwater was the result of the contribution of the spring snowmelt water, which had a significant influence on the lake water balance.

Chemical Weathering Rates of Soils Developed on Eocene Marls and Sandstones in a Mediterranean Catchment (Istria, Croatia)

Physical and chemical weathering, together with biological and biochemical processes, form soil from bedrock and strongly influence the chemical composition of natural waters. Erosive processes, primarily through the agents of running water and wind, remove the products of weathering from catchments. The aim was to determine the chemical weathering of minerals because of changes in land-use and natural forestation in two small neighboring catchments of the rivers Argilla and Bazuja. Agricultural land-use practice is very intense in the Argilla catchment, while the Bazuja catchment’s arable land is mostly abandoned, with progressive forestation. Chemical weathering in soils and sediments was evaluated with the aid of bulk chemistry analysis focused on major elements, trace elements, and zirconium. Weathering indices, mass balance, and strain were calculated. The abandonment of arable land and intense forestation in the Bazuja catchment caused increased chemical weathering with the loss of base cations (Ca and Mg) and enrichment of conservative elements (Zr and Ti) in surface horizons. EIC and MTF values are positive (enrichment) in areas with agricultural activities, while forested areas show negative values (loss). A comparison of the oldest and youngest parts of the overbank sediment profiles in the swallow hole zone and stream sediments shows that chemical and mechanical weathering in the Bazuja catchment was similar to present weathering in the Argilla catchment, while agriculture was active in the Bazuja catchment. The integrated knowledge gained in small catchment studies can be broadly applicable to larger systems.

Assessment of the ecological state of water bodies of the drainless area of the Ob-Irtysh River basin

Aim. Assess the current state of water bodies, compare with retrospective study data, update the bank of hydrological, hydrochemical and hydrobiological information.Material and Methods. Three groups of indicators were used: hydrological, hydrochemical and hydrobiological. Hydrological measurements were carried out to determine the flow of water in the rivers and their sections not covered by the Roshydromet observation system. Hydrochemical analysis of samples was carried out by ion chromatography and spectrophotometry and included the determination of basic cations and anions, organic substances and biogens. The assessment of water quality by hydrobiological indicators was carried out using the structural characteristics of phyto- and zooplankton.Results. According to environmental and sanitary indicators, the water quality of only three rivers - Solonovka, Cheremshanka and Burla (downstream) - belongs to class 4 (polluted waters). Most of the rivers have the 2nd class of water quality (clean).Conclusions. A trend towards an increase in the level of mineralization and metamorphization of the chemical composition of natural waters in the inland region of the Ob-Irtysh interfluve was revealed. The pollution of water bodies with organic substances and biogens was noted.

The Influence of the Chemical Composition of Natural Waters about the Triclocarban Sorption on Pristine and Irradiated MWCNTs

The influence of the chemical composition of natural waters on triclocarban (TCC) sorption on pristine and irradiated multi-walled carbon nanotubes (MWCNTs) at different temperatures was studied. Natural waters have been characterized in terms of the concentrations of cations and anions, pH, and electric conductivity. The sorption process of TCC on MWCNTs is influenced by both the chemical composition of natural waters and the variation of the temperature. The adsorption capacity of TCC on pristine and irradiated MWCNTs in the studied natural waters increased by increasing the temperature. The increase of the concentration of monovalent cations (Na+ and K+) in natural waters determined a significant decrease of the adsorption capacity of TCC on both pristine and irradiated MWCNTs while the increase of the bivalent cations (Ca2+ and Mg2+) determined an easy increase adsorption capacity. Freundlich and Langmuir models were selected to describe the steady adsorption of the TCC on the pristine and irradiated MWCNTs.

Ecological aspects of the state of natural and technical systems in the zone of irrigated agriculture effect

The purpose of the study is to identify the ecological aspects of the state of natural and technical systems in the zone of irrigated agriculture effect on the example of the hydrographic network of the left bank of the Lower Don. The Semikarakorsky district of the Rostov region was chosen as the object of the study. The subject of the study was the water quality in natural-technical systems – receivers of collector-drainage runoff from reclaimed lands, collector-drainage network, irrigation channels, as well as hydrochemical indicators of groundwater with a depth of no more than 5 m, soils from irrigated fields and fields with natural irrigation (boghara). The analysis of the results showed the widespread effect of groundwater on the formation of the drainage runoff and natural water composition, the accumulation of sodium ions and sulfates in soils, which is due to the rise of the capillary fringe due to the rise of the groundwater level. In general, the chemical composition of drainage water corresponds to the geochemical background of the territory and is a consequence of their natural desalinisation.

О гидрогеологических и гидрогеохимических закономерностях Оренбуржья и сопредельных районов

The complexity of the formation of hydrodynamics and chemical composition of natural waters of the Urals folded mountains and platform Pre-Urals is due to large differences in the geological structure and in the formation of fluids in the mountain-fold, platform, and transition zones. In addition, the properties and amount of waters in the hydrosphere in the supercritical state below the Conrad boundary are practically not investigated. Hydrogeochemical regularities are used in mapping, zoning of the territory, as well as for the interpretation of the actual material, and division of the cross-section in the drainage basins. For this purpose, concepts of hydrodynamic and hydrogeochemical floors, hydrogeochemical zones, hydrogeological and hydrogeochemical aquifer complexes and horizons are used. Each hydrogeological area is distinguished by its vertical hydrogeochemical zonation, which synthesizes the most essential features of the evolution of this structure during a particular period of history. As a result, chemical types of waters with zones of a certain thickness, successively replacing each other within adjacent areas or provinces (belts) are formed. The same type of zonation may also characterize a group of structures.

Specifics of Chemical Composition Origin of Surface Water in the Arctic Zone of Western Siberia

—One of the most urgent problems on which current studies of Arctic and subarctic territories are focused is how permafrost thawing can affect organic carbon fluxes and how these fluxes can influence the geochemistry of the surface and ground water. In addition to disturbing the carbon balance, permafrost thawing provokes the release of a significant amount of other chemical elements entering natural waters. The paper presents original data obtained by studying surface water in 2020 in the Yamalo–Nenets Autonomous District, which is situated in the Arctic zone of the Russian Federation. Permafrost is widespread in the study area, as also are facilities of the oil and gas industry. This predetermines the importance of research on the chemical composition of natural water, its formation, and ecological–geochemical status, which are critical aspects for assessing the anthropogenic load and predicting the influence of climate changes on the biogeochemical cycles of chemical elements. In the course of our fieldwork, 47 surface water samples were taken in the basins of the Taz, Pur, Ob, and Nadym rivers: 23 samples from rivers and streams and 24 samples from lakes and thaw depressions. The sampling sites were chosen to as comprehensively as possible cover the lake–stream–river system in the catchment areas of major rivers of the Yamalo–Nenets Autonomous District. The chemical composition of the water samples was analyzed at a certified laboratory using methods conventionally applied in solving such problems. The data were processed using statistical methods, including the principal component analysis (PCA). Data analysis demonstrates that surface water in the study area is ultrafresh, with neutral or weakly alkaline pH values. Hydrocarbonate, calcium, and magnesium ions dominate in the ionic composition of the water, and ammonium contents are high in the waters of the lakes and thaw depressions. In addition, the ammonium concentration strongly positively correlates with the content of dissolved organic carbon (DOC) and the values of chemical oxygen demand (COD) and permanganate index (PI). It was found out that the streams (springs and rivers) differ from the lakes and the water of the thaw depressions in higher concentrations of main ions that are brought to the water mainly by natural factors (these are {text{HC}}{{{text{O}}}_{{text{3}}}}^{ - }, Ca2+, Mg2+, and Na+) and higher total dissolved solids (TDS) and pH values. In contrast, the water of the thaw depressions is characterized by the highest concentrations of DOC and the values of other parameters related to organic matter (N–{text{N}}{{{text{H}}}_{4}}^{ + }, COD, and PI). It was shown that the main factors that control the chemical composition of the water are its interaction with organic matter from organic (peat) soil horizons and the mineral components of the underlying rocks and soils. The former factor most significantly impacts the water of the thaw depressions, and the latter one affects mainly the chemical composition of the rivers and streams. The relatively high contents of the chloride and sodium ions in the water of the largest lakes are probably caused by the anthropogenic load.

The Isotope Composition, Nature, and Main Mechanisms of Formation of Different Types and Subtypes of Salt Lakes in Transbaikalia

Abstract —More than a hundred lakes, groundwater, rivers, and precipitation of their catchments have been studied in Transbaikalia. The chemical composition of natural waters and the mineral composition of rocks and lacustrine bottom sediments have been analyzed. The isotope composition of waters, the isotope ratios in dissolved and deposited carbonates and in bacterial mats, and the content of heavy oxygen in the aluminosilicate fraction of bottom sediments and rocks in catchments have been determined. It is shown that all secondary minerals inherit the oxygen isotope composition of water, but their oxygen is isotopically much heavier than the water oxygen, because the water–rock interaction leads to the fractionation of oxygen and the transition of its heavy isotope into secondary carbonates and aluminosilicates. Bacterial mats using oxygen of carbon dioxide ions for their vital activity are also enriched in its heavy isotope. We have established that the water of soda lakes, being less saline than other lake waters, is more enriched in heavy oxygen isotope. Mineral analysis of lacustrine bottom sediments and material from sedimentation traps revealed chemogenic carbonates and secondary aluminosilicates. The performed thermodynamic calculations confirm their possible formation in lakes. It is shown that the lake water is in equilibrium not only with carbonates, clays, and hydromica but also with zeolites, and the most alkaline and mineralized water is in equilibrium with albite. The bottom sediments of soda lakes have a greater portion of clays and carbonates than those of fresh, chloride, and sulfate waters. The enrichment of salt lake waters with heavy isotopes is due not only to evaporation but also to the water–rock interaction. The contribution of aluminosilicate hydrolysis to oxygen fractionation is confirmed by the direct dependence of the “oxygen shift” value on pH, whose value is determined by the degree of the above interaction. We have established that the diversity of the chemical and isotope compositions of lake waters is due to their multifactorial formation related to the different degrees of lake water evaporation, the different mineralization of organic matter, and the different duration of the interaction of lake waters and groundwater with rocks.

Influence of cavitation processes on river water purification of mountain streams

Problems: The article considers the study of the influence of cavitation phenomena in hydrodynamically active areas of mountain rivers on the processes of natural self-purification of water. The paper considers the experimental results of determining the change in seasonal indicators of the hydrochemical composition of surface waters in the Stryi river basin.
 Objective: to determine the impact of hydrodynamically active areas (HAA) of mountain rivers on the processes of natural self-purification and to develop methods of laboratory modeling of these areas to determine the hydrochemical parameters of river waters.
 Methods of implementation: Research of ecological and hydrochemical factors of chemical composition of natural waters of the Stryi river basin combines basin and landscape-geochemical approaches, which allows to integrate various natural and anthropogenic influences, to identify the most important parameters for their detailed analysis. The combination of these approaches made it possible to improve the method of ecological analysis of the area of ​​the Stryi river basin, which allows to spatially differentiate and hydrochemically integrate the factors of formation of the chemical composition of natural waters.
 Results: It is stated that microbiological safety of water is a special problem, because even water from underground sources may contain single cells of pathogenic microorganisms, but the main threat is water re-contaminated with microbes in case of leaks in the water supply network.
 Conclusions: Analysis of the results of studies of the impact of self-cleaning processes in the river Stryi on the quality of water intake in Stryi showed that there are currently no negative effects of river waters of the river Stryi on groundwater deposits. The quality of river water is satisfactory for its use in domestic and drinking water supply and for recreational purposes.

Chemical composition of natural waters of the Lovozero massif, Russia

Chemical composition of natural waters of the Lovozero massif, Russia

Changes in the Composition of Natural Waters in the System “Atmospheric Precipitation–Soil Solutions–Soil-Ground Waters–Surface Waters (Based on the Example of the Klyazma River Landscapes)”

Changes in the Composition of Natural Waters in the System “Atmospheric Precipitation–Soil Solutions–Soil-Ground Waters–Surface Waters (Based on the Example of the Klyazma River Landscapes)”

ВИЙШОВ З ДРУКУ ПЕРШИЙ В УКРАЇНІ «ГІДРОХІМІЧНИЙ СЛОВНИК» (2022 р.)

The article presents and analyzes the scientific reference publication – “Hydrochemical Dictionary”, published by the professor of the Kiev National Taras Shevchenko University V.K. Khilchevskyi in 2022. Hydrochemistry is a scientific discipline that studies the chemical composition of natural waters (surface, underground and marine) and the patterns of its change depending on chemical, physical and biological processes occurring in the environment and under the influence of anthropogenic factors. Hydrochemistry has its own object of study, a theoretical, methodological and methodological basis, which allows it to develop important scientific and practical issues. It is closely connected with hydrology, geology, oceanology, and hydrobiology. Being formed in the process of formation and further development, hydrochemistry is constantly enriched with new terms and concepts. Yes, since the early 2000s. hydrochemical and hydroecological terminology has been influenced by the Water Framework Directive (WFD) of the European Union due to the deepening of international scientific contacts and the implementation in Ukraine of the provisions of the WFD in regulatory documents. Since an ever wider range of specialists is involved in this area, the issues of unification of hydrochemical terminology are becoming important. This goal is dedicated to the “Hydrochemical Dictionary”, which is the first in Ukraine scientific reference publication of this direction. The Dictionary includes terms widely used in the scientific literature on hydrochemistry, as well as a number of terms in related scientific disciplines related to hydrochemistry (hydrology, geography, hydrogeology, hydrobiology, analytical, organic and physical chemistry, geochemistry, etc.), the EU WFD. The “Hydrochemical Dictionary” contains terms covering the following issues: properties and chemical composition of natural waters; processes of formation of the chemical composition of natural waters; methodology and methods of hydrochemical research and water analysis; processes of pollution and self-purification of water bodies; hydrobiological and microbiological processes in water bodies; water quality and integrated water resources management. The Dictionary contains about 830 terms and concepts listed in the subject index, which makes it easy to find the right terms on the corresponding pages. “Hydrochemical Dictionary” is designed for students of universities specializing in “Earth Sciences” of educational programs of the hydrological profile, studying hydrochemical and hydroecological disciplines; will be useful to specialists in the field of hydrochemistry, hydrology, hydroecology, hydrogeology, geography.

Comparative Analysis of the Chemical Composition of Natural Waters in the Khanty-Mansiysky and Yamalo-Nenets Autonomous Districts

Background: Water is a key source of life on Earth; it is involved in the transfer of nutrients, macro- and microelements between soil, plants, animals and humans, as well as in the concentration and dispersion of chemical elements and the formation of minerals. The elemental status of the population is largely determined by the chemical composition of the natural waters on the territory of residence. Objective: To perform a comparative analysis of the concentrations of iron, manganese, calcium and magnesium in natural waters of the Khanty-Mansiysk and Yamalo-Nenets Autonomous Districts (Okrugs). Materials and methods: We established concentrations of iron, manganese, calcium and magnesium in 100 samples of natural waters taken from rivers, lakes, backwaters, channels, etc. of the Khanty-Mansiysk and Yamalo-Nenets Autonomous Districts, 50 samples each, using spectrophotometry, capillary electrophoresis and atomic absorption spectrometry. The results obtained were compared with the reference values provided in Russian sanitary rules and regulations SanPiN 1.2.3685–21. Results: We established elevated levels of iron in most surface water samples from both districts and of manganese in the Khanty-Mansi Autonomous Okrug accompanied by extremely low concentrations of Ca and Mg in the vast majority of all samples. At the same time, we registered significantly lower concentrations of Ca (p = 0.012) and Mg (p = 0.021) in the water samples from the Yamalo-Nenets Autonomous Okrug compared to those from the other district. Conclusion: In the population of the Tyumen North, the constant use of such water for drinking purposes can lead to the early development and rapid progression of cardiovascular and osteoarticular diseases, type 2 diabetes, neoplasms, etc.; at the same time, people are at risk of generalization of immunosuppressive conditions, diseases of the central nervous system, gastrointestinal tract, oxidative metabolism disorders, etc.