Chemical Composition Of Water Research Articles

Comparison study of conventional underwater electrodes and electrodes with additional modification of mg

The influence of water depth, microstructure, chemical composition, welding defects, and mechanical properties affect underwater welding. In addition, the determination of electrodes for underwater welding requires unique properties, including being able to cause arcing and slag to grow on the surface of metal deposits which can protect against the effects of oxides and low hydrogen solubility. The electrodes must meet the AWS D3.6M underwater welding specification standard. In this study, the steel plate material used in AH-36 and implemented for underwater wet welding by comparing two electrodes, namely E6013 with additional Mg modifications and Broco E70XX electrodes specifically for underwater wet welding, the other Mg on E6013 rutile electrodes with modification 1 ( 3% Mg) and Modification 2 (5% Mg). The welding method with a heat input of 1.5 kJ/mm with 130 A and 2.5 kJ/mm with 140 A is carried out at 5m. The radiographic test results showed that the welded specimens at a depth of 5m showed imperfect penetration defects. It may be due to the effect of significant pressure and higher cooling rate that the weld melt cannot penetrate completely into the parent material. The tensile test results also showed an insignificant increase in the strength of the underwater welding, and the elongation was quite significant. Occurs at the E6013 electrode with modification 1 (3% Mg) and Modification 2 (5% Mg). The increase is not too significant. Penetration is not perfect. Due to significant pressure and a higher cooling rate, the molten weld cannot penetrate completely into the parent material. However, for testing the Broco E70XX electrode where there is no change in microstructure, such as electrodes modified with magnesium where only grain growth occurs, and there is Spheroidite which makes the microstructure related to mechanical properties, namely ductile.

Nature-inspired hybrid wettability surface to enhance water management on bipolar plates of PEMFC

Proton exchange membrane fuel cell (PEMFC) requires both sufficient water in proton exchange membrane (PEM) and fast water drainage in flow channel to achieve a desirable performance, which creates a dilemma for water management. Herein, we have fabricated a nature-inspired bionic multifunctional surface (BMS) consisting of superhydrophobic coating and superhydrophilic groove. The characterizations of water contact angle, morphology and chemical composition have verified the successful preparation of hybrid wettability surface. The effects of groove width on droplet capture, storage and drainage have been investigated, which yields an optimal width of 600 μm. More importantly, BMS has been fabricated inside the flow channel of graphite bipolar plate (BMS@BP). The peak power density of BMS@BP cell is 26.3% higher than that of the cell without BMS. Under a drought-inclined condition of low current and humidity, BMS@BP mitigates the increase of internal resistance caused by PEM dry-out, whereas under a condition prone to flooding (high current and humidity), BMS@BP can reduce the voltage fluctuation and pressure drop variation incurred by flooding. Hence, BMS has demonstrated a capacity to balance the opposite needs of moisturizing PEM and draining channel water. Our work may afford an innovative hybrid-wettability-based approach to enhance water management for PEMFC.

Laboratory Testing Pros and Cons Over Natural Grey Water and Synthetic Grey Water Testing

Abstract: This abstract explores the advantages and disadvantages of laboratory testing over natural grey water and synthetic grey water testing. Grey water refers to water that has been used in household activities such as washing dishes and laundry. Laboratory testing involves conducting experiments in a controlled environment using standardized protocols to measure the effects of grey water on various parameters, including chemical, physical, and biological characteristics. Natural grey water testing involves studying the effects of grey water on the environment in its natural setting, while synthetic grey water testing involves creating a standardized solution that mimics grey water's chemical composition.

Chemical Elements Concentration, Variations in Mineral Composition, and Current Rate of Sedimentation in Sapropel Deposits of Small Lakes in the Taiga Zone of Southern Siberia

Abstract —We studied the bottom sediments of lake systems located in the taiga landscape of Siberia. In the south of Western Siberia, there are 11 lakes in the subzone of the south taiga and 9 lakes in the subtaiga subzone. On the territory of the south of Eastern Siberia in the taiga zone there are 10 lakes on the southern coast of Lake Baikal, 5 lakes on its east coast and 6 lakes are located on the territory of the national park “Alkhanai” in Transbaikalia. Studies of the chemical composition of water, soil, and sediment samples were conducted at the Analytical Center for Multi-Elemental and Isotope Research SB RAS, Novosibirsk. The use of a complex of modern analytical methods in the study of the same lake samples made it possible to obtain more reliable information (1861 samples of bottom sediment were studied). Quartz and feldspars of pelitic dimension dominate in the mineral composition of the terrigenous fraction, organic matter and authigenic minerals (opal, pyrite, illite and sometimes calcite) are added to them during the bottom sediments formation. The absolute contents of the studied elements in the bottom sediments of all lakes are lower than their concentrations in the upper continental crust and sedimentary rocks of the Russian Plate, with the exception of Si, Hg, Cd. In the lakes of the subtaiga of the south of Western Siberia, an exception was established for Ca in the bottom sediments of which carbonates predominate. Contents variations of a number of elements in the bottom sediments of taiga lakes in different regions do not significantly differ. The dispersion of their concentrations between lakes with a total catchment area and lakes from different regions are comparable (Ca, Sr, Al, Mn, Fe, Cd, Hg, etc.). The current sedimentation rate in natural occurrence in the lakes of the taiga zone (southern Siberia) vary from 1.1 to 2.9 mm/year. Moreover, it is comparable to the current sedimentation rate in the lakes of the forest-steppe and steppe zones of south of Western Siberia.

Storage, quality and use of rainwater after a "green" roof

The issue of reuse of natural resources occupies an important place in resource conservation, environmental friendliness and reduction of the man-made load of construction around the world. The use of water resources is of particular importance. They are a strategic, vitally important natural resource, the national wealth of every country, one of the natural foundations of its economic development. In addition to reasonable consumption, it is necessary to promote the preservation, restoration and reuse of water resources. One of the many methods of effective and at the same time the most natural management of water resources is "green" constructions. These are biotechnological means that combine building structures and living plants. This paper examines the implementation and creation of "green" roofs for the collection, accumulation and re-use of rainwater. The chemical composition of water after passing through the "green" roof, as well as ordinary rainwater from the roof of the building of the residential complex "Respublika" was analyzed. Water sampling was carried out in December 2021 during rainfall. It is shown that the concentration of impurities in wastewater from "green roofs" does not exceed the permissible values for drinking water. In addition, financial costs for the construction of conventional and "green" roofs were presented. Additional costs for the creation of a "green" roof will be 20.89% of the total cost of materials and 63.49% of the total cost of works for the construction of a stationary roof. Means for reuse of rainwater on "green" roofs are considered. It is shown that thanks to the retention of water by the layers of the "green" roof with an area of 490 m2, it is enough to provide a tank with a volume of 150...250 dm3. Data on the volume of used water for technical needs (irrigation) from Faina-Town residential complex in Kyiv are provided. It is shown that the accumulated rainwater is sufficient to meet the needs for watering the adjacent territory.

Impact of Gravel Pits on Water Quality in Alluvial Aquifers

Gravel pits are considered potentially hazardous in terms of groundwater quality protection as they represent an open part of the aquifer system, increasing the aquifer’s vulnerability to contamination from the surface. The aim of this research was to determine the biogeochemical processes in gravel pits that have a positive effect on the groundwater quality in the alluvial aquifer in NW Croatia. The aquifer is situated below developed agricultural land, with high groundwater nitrate concentrations having been recorded over the last decades. The differences between two gravel pits and the surrounding groundwater were studied using in situ, hydrochemical, and isotopic parameters (δ15N-NO3 and δ18O-NO3), together with existing microbial data. The analyses of nitrogen species indicated that nitrate attenuation processes take place in gravel pits. Bacterial denitrification and nitrate uptake by algae were responsible for significant decreases in nitrate concentration. These processes were more effective in the inactive gravel pit, which has a longer water residence time and during warm periods, when microbial biomass, abundance, and activity were high. The seasonally variable microbial activity also affected trace metals, removing them from groundwater, possibly through the biosorption of metal ions. The presented research shows that the observed biogeochemical processes are associated with seasonal changes that affect the types and number of microbial communities and the chemical composition of water, resulting in gravel pits being groundwater remediation points.

Use of Hydro-chemical Tools to Improve Definitions of the North-Western Sahara Aquifer System, Case of Ouargla Groundwater, Algeria

The North-Western Sahara Aquifer System (NWSAS) is a complex multi-layered aquifer system with extraordinary continental groundwater reserves. This largest aquifer in the world straddles three countries: Algeria, Libya, and Tunisia. It contains more than 50,000 billion cubic meters of water; of which, 70% is in Algerian territory in the southeast of the country. This water is the result of accumulation over 1 million years. In the Wadi Mya basin (Algeria), this system is characterized by two overlaid aquifer systems: the complex terminal (CT), a shallow aquifer housed in the Senonian-Eocene and Mio-Pliocene formations, and the continental intercalary (CI), a deep aquifer hosted in the Albian, Aptian and Barremian formations. The main purpose of this study is to carry out a correlation between the geochemical composition of the water and the facies of the aquifer formation. The adopted approach will allow deciphering the hydro-chemical relationships between the different levels of the two aquifer systems in the Wadi Mya basin. To acquire the chemical composition of water, the study method goes through a targeted sampling and physicochemical analysis of water followed by a statistical analysis as well as correlation and geochemical modelling: the interpretation of specific diagrams (Piper), correlations between chemical elements in binary graphs, and principal component analysis (PCA). The performed geochemical modelling by examining the saturation index and chemical balance of water helps to better understand the origin of mineralization, elucidate the mixing of waters originating from different aquifers, as well as highlight the relationship between deep and shallow aquifers in the Wadi Mya Basin hydrodynamic conversion. The obtained results indicate that the overall mineralization occurring within the study area is dominated by sodium chloride and calcium chloride-sulfate facies. This can be explained by the dissolution of halite, gypsum, and anhydrite evaporitic rocks, intercalated in the aquifer matrix besides the effects of the extended stay of fossil waters with low recharging and cation exchange reactions resulting from water-rock interactions. The interference recorded between the geochemical signatures of the two aquifers favors the hypothesis of interconnection between aquifers through fractures. Through the implementation of such academic research, this invaluable source of life will stay sustainable for future generations.

TAXONOMIC ANALYSIS OF THE ALGOFLORA OF THE AKDARYA RESERVOIR IN THE MIDDLE REACHES OF THE ZARAFSHAN RIVER

As a result of flora-systematic studies of the Akdarya reservoir, 71 species and varieties (63 species, 16 variations, 1 form) were identified, which belong to 4 departments, 10 orders, 14 families, 24 genera. The species composition is dominated by diatoms (Bacillariophyta), consisting of 56 species of varieties, followed by detached green (Cyanophyta) - 9 (8 species, 1 form), yellowish (Xanthophyta) - 4, green (Chlorophyta) - 2 species of algae. Hormogoniophyceae, Pennatae and Heterotrycho phyceae are the most diverse classes, representing 65 species and varieties (91.54%), consisting of 6 families, generalized by 62 different species (87.95%), and 7 genera, generalized by 53 (74, 64%) species and varieties. The flora-systematic analysis shows that the species composition of the Akdarya Reservoir’s algophore has a peculiar feature, where the data obtained in the Far East can be used in the study of the ecosystem of the Akdarya Reservoir, as biodiversity of primary producers.
 Background. The reservoir plays a major role in the formation of ecosystems of certain geographical areas. The comprehensive study of biodiversity in a reservoir makes it possible to study and monitor environmental and biological changes in environmental factors. For this purpose, a preliminary inventory of the state of the aquatic environment and its organisms is carried out. In this regard, the objective of our research is the taxonomic analysis of the Akdarya Reservoir’s algophore.
 Materials and Methods. In 2014-2022 from Akdarya reservoir-More than 150 alhologic samples have been collected and processed according to the generally accepted methods of alhology and hydrobiology [5, 6]. In the laboratory, preparations were prepared from algological samples, species compositions of algae were identified by determinants and frequency of occurrence in one lens field of view was determined. The experiments were carried out using a Carl Zeiss type light microscope, eyepiece +7 micrometer, and dyes. Species composition of algae, systematics and their taxonomy have been identified with the help of the determinant [4-11, 16] and the monograph [12, 17, 18]. The chemical composition of water is analyzed by the data of UzGMNII (Uzbek Hydrometeorological Research Institute).
 Results. Based on taxonomic analysis, 71 species and varieties of algae (63 species, 16 variations and 2 shapes) were identified in alhologic samples from the Akdarya reservoir. They belong to 4 divisions (Cyanophyta, Bacillariophyta, Xanthophyta, Chlorophyta), 8 classes, 10 orders, 14 families and 23 genera, which are given in table 1.2.
 Conclusion. The Akdarya reservoir in the middle of the Zarafshan River has a large amount of suspended substances and relatively high mineralization. This factor favourably influences the development, formation and intensive distribution of the algae division of Bacillariophyta (56), Cyanophyta (9), Xantophyta (4), Chlorophyta (2) in the ecosystem of the Akdarya reservoir. The obtained data can be used in the distant biodiversity of the primary producer of the ecosystem of the reservoir.

The role of the HADES URL in better understanding of the Boom Clay pore water geochemistry

Abstract When assessing a rock formation for its suitability as a potential host rock for the disposal of radioactive waste, knowledge about its pore water chemical composition is essential. When the HADES underground research laboratory became operational in the early 1980s, it offered the possibility of extracting pore water from Boom Clay. At the time, however, there was almost no experience of sampling pore water from deep clay formations. The low hydraulic conductivity of clays makes it difficult to extract pore water and the sampling process itself can induce changes in the observed chemical characteristics due to oxidation and re-equilibration with the ambient air. In the past decades, significant progress has been made in the techniques and protocols to sample and monitor pore water. The use of nitrogen instead of compressed air to drill boreholes and installing piezometers limited the disturbances induced by oxidation of the clay. Furthermore, an advanced system was developed to simultaneously sample pore water and dissolved gases and measure some key geochemical parameters such as pH, pCO 2 and redox potential under in situ conditions. This has resulted in a more reliable characterization of the Boom Clay pore water and a better understanding of perturbing processes such as oxidation.

Multivariate data analysis applied to groundwater geochemical characterization, Central Pacific, Costa Rica

This research has allowed to provide new information about the geochemical groundwater composition in the Central Pacific of Costa Rica, a place with an important commercial, touristic, and real estate development with a continues water resource demand. Previous reports of iron and manganese elevated concentrations, and flow water rate decrease in production wells, turn the area into an object of hydrogeological studies as the resource demand increases. The main objective of this research was to provide information about the quality and composition of the groundwater, and to understand the relationship with the geological and structural context. A total of 25 groundwater samples were collected, subsequently hierarchical clustering method were applied to analyze chemical concentrations and characterized the groundwater. Results showed some samples with atypical trace elements concentrations such as Al, Mn, and Fe, which are above the water quality limits. After applied the hierarchical clustering, results evidence the presence of two main clusters, which one cluster have samples with high temperatures and mineralized waters in common. The groups are distributed between three major neotectonics faults Barranca, Jesús María, and Tárcoles that creates a complex structural context that provides pathways movement for the contribution of thermal waters which can strongly dissolve the rocks, and provide a certain water chemical composition related with the presence of volcanic rocks with high concentrations of K, Mg, Mo, P, Rb, Si, Fe, Mn, F and U, and sedimentary rocks with high concentrations of B, Ba, Ca, Cu, Fe, Ge, Li, Na, S, SO4 and Zn.

Hydrochemical and isotopic composition of periglacial watersheds in Northern Patagonian Andes

Mountain periglacial environments are important sites of water storage and distribution to downstream areas. The present study was conducted in the “La Hoya” subwatershed, in the Northern Patagonian Andes. La Hoya is the main water recharge area of the “Los Bandidos” watershed, from which fresh water is used for human consumption. The aim of this work was to study the hydrogeochemical and isotopic composition of this watershed and evaluate the hydrological and ionic contributions from periglacial landforms, accounting for annual water flow hydrodynamics and climatic trends. Meteorological data, spring and stream flows, electrical conductivity, isotopic content, and major ion concentrations of snow, spring, and stream samples were analyzed from December 2020 to November 2021. Snow melting is the main water contribution to the mountain watershed. Part of the snowmelt drains superficially during the melting season and part of it infiltrates into periglacial landforms, where it is provisionally stored as groundwater. Chemical weathering during groundwater-rock interaction is the main process that regulates water chemical composition, dominating the dissolution of CO2(g) and carbonates, which controls the waters to be of the Ca–HCO3 to Ca–Mg–HCO3 facies type of groundwater. The climate tendency for the last sixty years in this area reflects a decrease in precipitation and an increase in temperatures. This climate trend could affect periglacial environments, modifying the chemical and physical processes that take place in them, which could affect the chemical water quality and the hydrological behavior of the watershed. The chemical and hydrological behavior in watersheds for human consumption should be specially monitored for better use of this resource.

Production of Drinking Water with Membranes with Simultaneous Utilization of Concentrate and Reject Effluent after Sludge Dewatering.

A new technology is described that enables us to completely exclude liquid discharges during production of drinking water from surface sources. The proposed described technological scheme separates the natural water into a stream of purified drinking water and dewatered sludge. The sludge moisture has a value of 80 percent. The experimental program is described to treat the natural water with nanofiltration membranes and to produce a drinking-quality water with recovery value of 0.99 and higher. Concentrate of membrane plant is mixed with the wet sludge and the reject effluent after sludge dewatering is again treated by reverse osmosis membranes and returned back to the sludge thickening tank. Results of experiments to treat reject water after sludge dewatering are presented. The use of nanofiltration membranes provides reduction in the Total Dissolved Solids content (TDS), aluminum, color and oxidation to meet drinking water standards. Experimental plots are presented that can be used to select membrane characteristics and to predict product water chemical composition at each stage of the membrane treatment scheme. Concentrate of membrane treatment plant is mixed with the wet sludge in the thickening tank. The sludge, after the thickening tank, is dewatered using either filter-press or centrifugal equipment. The reject (or fugate), after sludge dewatering, is treated by membrane facility to separate it into deionized water stream and concentrate stream. The deionized water can be mixed with the feed water or drinking water and the concentrate stream is returned back to the thickening tank. Thus, the salt balance is maintained in the thickening tank, whereby all dissolved salts and impurities that are rejected by membranes are collected in the thickening tank, and then are withdrawn together with the dewatered sludge. Based on the results of experimental data processing, balance diagrams of the sludge dehydration process with waste water purification at the membrane plant and with the addition of the membrane plant concentrate to the sludge thickener are presented, according to which all contaminants removed by the membranes are removed together with the sludge.

Wielkość dostawy wybranych zanieczyszczeń atmosferycznych i ich wpływ na jakość wód w zurbanizowanej zlewni Różanego Strumienia w Poznaniu w latach hydrologicznych 2016‑2020 = The level of supply of selected atmospheric pollutants and their impact on water quality in the urban catchment of Różany Strumień in Poznan, Poland, in hydrological years 2016‑2020

The main aim of the work detailed here was to identify the level and composition of selected atmospheric pollutants supplied mainly with precipitation to the urbanized Różany Strumień catchment in Poznań, Poland; and to determine their impact on the chemical composition of water at subsequent stages of its circulation. The research was conducted in the hydrological years 2016-2020 as part of the Integrated Monitoring of the Natural Environment in Poland (ZMŚP) program, using the infrastructure of the ZMŚP’s "Poznań-Morasko" Base Station – of Adam Mickiewicz University in Poznań – the first such Base Station to be located within the boundaries of a large urban agglomeration. A key finding concerned a positive ion balance among nutrients supplied as a result of human activity (e.g. through fertiliser use) – involving NO3-, NH4+ and K+. Remaining chemical components (denudation ions) present in the waters circulating in the catchment are in turn characterised by a negative balance.

Study of biological treatment of domestic and municipal wastewater using microscopic algae

The article presents the results of research on improving the technology of biological treatment of domestic and municipal wastewater by microscopic algae at the Bektemir treatment plant in Tashkent. Growth, development, yield and hydro - chemical composition of water by growing algae at concentrations (50, 75, 100%) and the effectiveness of biological treatment of wastewater in a semi-finished device have been studied.

ХАРАКТЕРИСТИКА ХІМІЧНОГО СКЛАДУ ВОДИ ТА ГІДРОХІМІЧНОГО РЕЖИМУ ЛІВОБЕРЕЖНИХ ПРИТОК ДНІСТРА В МЕЖАХ ТЕРНОПІЛЬСЬКОЇ ОБЛАСТІ

The article is devoted to the study of the chemical composition of water, the hydrochemical regime and water quality of the left-bank tributaries of the Dniester within Ternopil region (Zolota Lypa, Koropets, Strypa, Seret, Nichlava and Zbruch rivers) based on water monitoring data of the State Water Agency of Ukraine (1993-2020). The chemical composition of water was studied according to: main ions and water mineralization; physical and chemical parameters (pH, O2); biogenic substances ((NН4+, NO2–, NO3–, РO43–); trace elements (Cu, Cr); specific pollutants (petroleum products, detergents). It was established that the hydrochemical type of water in most of the studied rivers is calcium bicarbonate. The water of the Nichlava River is calcium bicarbonate-sulfate. The average annual water mineralization of the studied rivers varies from 476 mg/dm3 to 699 mg/dm3. The water of most rivers is moderately fresh in terms of mineralization. The water of the Nichlava River is fresh with high mineralization. The hydrochemical regime of rivers is related to the hydrological regime. The minimum concentrations of the main ions and water mineralization are observed during the summer-autumn mezhenia, which is explained by the precipitation of a significant amount of atmospheric precipitation and the presence of floods during this period. The maximum of these indicators is observed in winter. The hydrochemical regime for biogenic substances, trace elements and specific pollutants is less pronounced. Among biogenic substances, the clearest manifestation of the hydrochemical regime was recorded for nitrates. The minimum concentrations of NO3– are observed in the summer-autumn boundary, when nitrates are consumed for the development of aquatic plants. Nitrates accumulate in the autumn period with the death of aquatic plants, and during the winter period, their maximum average content is observed. The assessment of the water quality of the studied rivers, carried out by analyzing long-term series of observations using the “Hygienic water quality standards of water bodies … (2022), showed that the content of the studied components mainly met the regulatory requirements, with the exception of iron. At the same time, the absence of copper, chromium, petroleum products and detergents in water was recorded in all studied rivers during the observation period in different years (zero values of these components were recorded in 70-90% of samples).

ГИДРОГЕОЛОГИЧЕСКоЕ СТРОЕНИЕ БУЗАЧИНСКОГО АРТЕЗИАНСКОГО БАССЕЙНА (ЗАПАДНЫЙ КАЗАХСТАН)

The largest structural element of the Buzachi structural-tectonic zone is the North Buzachi Uplift, which is limited from the south by the South Buzachi, and in the north and northeast by the Kultuk depressions. The Buzachi artesian basin is confined to the Cretaceous deposits of the Aptian–Turonian age. The physical properties and chemical composition of waters from productive strata are closely related to the conductive properties of sedimentary strata. The available hydrogeological materials for the area under consideration make it possible to single out two hydrogeological systems in the basin. The upper system is groundwater of Quaternary deposits. The lower system includes aquifers of the Jurassic, Lower Cretaceous and partly Upper Cretaceous (Cenomanian – Lower Turonian), and from above they are limited by Senonian and Paleogene beds with low conductive properties.

Photochemical processes in surface water bodies and their potential impacts on the chemical composition of water: A review

AbstractThe present study is a review of photochemical processes that occur in surface water bodies and which can affect the chemical composition of water. It is expected that water bodies with a slow rate of water exchange, including lakes, reservoirs, estuaries and ponds with significant areas of shallow water will be most vulnerable to the impacts of these processes. It involves natural organic compounds and xenobiotics of organic origin that enter water bodies from anthropogenic sources or are formed in water bodies because of the development of cyanobacteria and other algae species. Photodegradation of dissolved organic matter (DOM) occurs as a result of both direct photolysis and photosensitized cleavage involving inorganic and organic compounds, which are characterized by chromophore properties, such as humic substances. Photolysis is accompanied by the transformation of high molecular weight organic compounds into lower molecular weight compounds that can become bioavailable to, and promote the development of, microorganisms. Photodegradation results in bioavailable forms of nitrogen and phosphorus being released into the water column. Accordingly, the present study presents the results of analysis of the photochemical destruction of humic substances, such as the most widespread group of the surface water body DOM under the influence of artificial UV irradiation and solar radiation. The results provide data on the products of humic substances photolysis, as well as the influence of the latter on the destruction of a number of organic substances, including xenobiotics (herbicides, pesticides, etc.). Photolysis of algotoxins, which are mainly concentrated in the water of highly trophic reservoirs and lakes during the period of water “blooming,” is among the main concerns being addressed, noting photochemical destruction of these dangerous toxicants can be considered an important means of removing them from drinking water. Also emphasized is that photochemical processes in surface water will likely intensify in the future amid the recent climate changes, also affecting the chemical composition of water.

Геоэкологическая характеристика водного объекта без названия, расположенного вблизи рекультивированного полигона твердых коммунальных отходов Калининградской области

The article presents the results of a study of one of the artificial reservoirs in Kaliningrad – a pond w / n with coordinates 54°69ʹ90ʺ N, 20°36ʹ46ʺ E. (hereinafter – the pond), located 0,4 km south of the reclaimed municipal solid waste landfill (hereinafter – the MSW landfill) in the settlement named after A. Kosmodemyansky (Kaliningrad) and 0,6 km from the water area of the Vistula Bay, which is a reservoir of the highest category, which is both amateur and industrial fishing. Through the pond, since the formation of the MSW landfill in 1978, there has been a surface runoff of water containing leachate from the waste dump. After landfill reclamation, the pond is studied for the state of its biota, the chemical composition of water and bottom sediments. The objectives of this study include assessing the degree of impact on the aquatic ecosystems of the MSW landfill by studying the relief features of the pond basin, determining and comprehensively analyzing the obtained morphometric indicators that have a significant impact on the appearance and development of the reservoir, its hydrological regime, the distribution of physicochemical parameters in the thickness water and the current ecological state. In 2021, a bathymetric survey was carried out using a Lowrance HDS-16 echo sounder-chartplotter, during which information about the current depth and geographic coordinates of the studied bottom area was jointly recorded in real time. For the first time, maps of the relief of the bottom of the pond in 2D and 3D format were built. Investigated the drainage basin of the pond. During the subsequent analysis of the obtained results, the main morphometric parameters of the pond were determined. According to the results of calculations, the pond can be attributed to shallow ponds of medium size, with a water surface area of 0,035 km2 and an average depth of 1.8 m. The outlines of its coastline are close to a square.

РАДОН В МИНЕРАЛЬНЫХ ВОДАХ СИХОТЭ-АЛИНЯ (ПРИМОРСКИЙ КРАЙ)

Geological and hydrogeological conditions of 19 occurrences of thermomineral water in the southern Far East of Russia are considered in the paper. Concentrations of radon were measured in waters and those of uranium and thorium in host rocks and secondary minerals. The results were compared with the chemical composition of waters and gases in the mineral springs. It is established that water-bearing rocks are classified into rocks of low and normal radioactivity. The contents of uranium (< 0.56 µg/l) and thorium (< 0.1 µg/l) in the waters are low. Measurements of radon concentration in mineral water springs occurring in Primorye indicate that most of them are weakly radioactive (0.2–1.5 kBq/l), whereas two are moderately radioactive (1.5–7.5 kBq/l). From a medical-balneological point of view, waters in 7 out of 19 springs were defined as radon waters, with four of them classified as nitrogen thermal water and three as CO2-rich mineral water. CO2-rich mineral waters of the Shetukhinskaya group exhibit the highest level of radioactivity. Such nature-made objects reflect the state of the geological environment and can be utilized both for medical purposes and for monitoring a wide range of hydrogeochemical parameters. Based on the analysis of geological conditions and geochemical features of thermomineral water occurrences, the factors that determine the level of radioactivity were identified and general schemes were proposed for the transport of radon to the surface in various geological and hydrogeological conditions.

Results of studying the chemical composition of water of different types of reservoirs

The aim of the study was a comparative description and assessment of seasonal dynamics of organoleptic characteristics, salinity and chemical composition of the water of some reservoirs in Uzbekistan. It was found, that the organoleptic characteristics and parameters of salinity of Kattakurgan reservoir in the spring and summer were practically within the MPC. Indicators of chemical composition of water of Kattakurgan reservoirs were below the upper limit of the MPC. In water samples of Tuyamuyun reservoir organoleptic characteristics and parameters of salinity in summer was higher than the MPC. Indicators of the chemical composition of water in the summer were below the upper limits of the permissible level, reliable inter-seasonal differences noted on the content of chlorides and sulfates. Organoleptic characteristics and the degree of mineralization of water samples of Charvak reservoir were within the MPC. All parameters of the chemical composition of water of Charvak reservoir were lower relative to the upper border of the MPC, regardless of the place of sampling and the time of year. Keywords: reservoirs, water of reservoirs, chemical composition, salinity of water, organoleptic characteristics.