Composition Of Water Research Articles

Geochemistry and formation conditions of the natural water composition in the nothern outskirts of Kazan

Kazan is located on the left bank of the Kuibyshev water reservoir in the east of the Russian Plain. The Blue Lakes, which are unique salt-water karst lakes in the Middle Volga region, appear to be a real natural treasure in the northern outskirts of the city. On the basis of field and analytical data obtained in 2023, the geochemical composition of the natural water is studied in the Blue Lakes, the Solonka and Kazanka rivers, uprising springs, and snow cover. Significant variations in the hydrochemical field are controlled by the effect of discharging relatively deep sulfate calcium groundwater from the lower Permian carbonate-sulfate deposits with a mineralization of about 2.5 g/l. The shares of these artesian waters in the river discharge have been determined. They are about 80% for the mouth of the Solonka River in the initial period of summer low water and about 50–60% for the lower reaches of the Kazanka River in the initial period of winter low water. Maximum values of deep water inflows are observed in river valleys along fracture zones of submeridional and northeastern orientation. The stability of hydrochemical parameters in the studied water bodies over time is shown, which is due to a high rate of water exchange and a low anthropogenic impact on the environment. Complexes of microcomponents concentrated in artesian and near-surface waters have been identified. In artesian waters such components are: Ca, Sr, Mg, Li, U, Re, Se; and in the near-surface – K, Fe, Mn, Ba, As, Co. It is noted that in order to determine the degree of surface water pollution, it is important to take into account the conditions of their composition formation and to distinguish between excess concentrations caused by natural and anthropogenic factors.

Arsenic in water from the Bystre Thrust-Sheet (Outer Carpathians, Poland): Geological and environmental implications

The article focuses on the physicochemical parameters of water in streams, springs, boreholes, and intakes from the Bystre Thrust-Sheet (the Silesian Nappe, Fore-Dukla Zone), the only area in the Polish segment of the Outer Carpathians where arsenic minerals occur. These waters are characterized by the presence of arsenic, lithium, mercury, barium, strontium and usually high CO2 concentrations. The study aimed to determine the range of the geochemical anomaly of arsenic in water. An important aspect was to determine the origin of As and link its presence with the content of ions of other chemical elements dissolved in water. The sampling points were designated based on geological maps with a particular emphasis on the occurrence of tectonic dislocations and the configuration of the river network. In the selected places 47 samples of water were taken, and various elements were determined. Then, the range of occurrence of various types of water that differed from the average concentrations of selected ions was analysed. The potential relationship between the chemical composition of water and the geology of the Bystre Thrust-Sheet was also discussed. The high concentrations of arsenic were found only in springs and boreholes. In flowing waters, these concentrations quickly decreased due to dilution or precipitation and binding with the solid phase. Relatively high (max. 378.72 μg/L) arsenic concentration, which significantly exceeded the permissible value (50 μg/L), was detected in the Bystre 1 borehole. This water has a pH value of 7.85 indicating its alkaline nature. When considering water use for health purposes, it is necessary to monitor its arsenic content. The conditions prevailing in waters, mainly high pH, favour the immobilization of metals in sediments and suspended matter. The lower concentrations of arsenic in flowing waters may be attributed to the strongly calcareous nature of the Cieszyn beds which act as a natural barrier, limiting the migration of arsenic beyond the Bystre Thrust-Sheet.

Relationship between the chemical and isotopic composition of natural waters and the newest tectonic structure in the area of Lake Glubokoe (Moscow region)

Relevance. The tectonic factor affects the hydrogeological conditions. To assess the tectonics impact on hydrogeological conditions, it is necessary to use an integrated approach. The article considers the hydrogeochemical features of groundwater formed in the area of Lake Glubokoe in the Moscow region, confined to the so-called Trostenskaya depression. Aim. To identify the isotope-chemical characteristics of groundwater due to the effect of the latest tectonic structure of the area. Methods. The chemical composition of natural waters was monitored using ion chromatography on a high-performance ion liquid chromatograph LC-20 and inductively coupled plasma mass spectrometry on an Agilent 7700 x spectrometer. The contents of stable isotopes of oxygen (δ17O and δ18O) and hydrogen (δD) were determined by laser light attenuation spectroscopy with an annular multi-pass cuvette on a Picarro L2140i analyzer. Results and conclusions. The groundwater of the Podolsk-Myachkovsky aquifer complex in the area of development of the Trostenskaya depression is characterized by increased mineralization, as well as a higher content of bicarbonates and calcium, compared to groundwater common in the peripheral parts of the research area. Higher concentrations of micro-components (strontium, barium, scandium, rubidium, etc.) were recorded within the studied structure. Groundwater characterized by a heavier isotopic composition (δ18O, δD, δ17O) is also confined to the Trostenskaya depression. Data on the ratio of δ18O, δ2H and δ17O in natural waters were obtained for the first time for the studied area. It is likely that groundwater in the central and northwestern parts of the study area has a heavier formed isotopic composition due to the inflow of water in the postglacial period.

Experimental Investigations on the Dissolution Process of Dolomite by Sulfate-Rich Geothermal Water: A Case Study of the Shuijing Hot Springs in Guizhou Province

The dissolution of dolomite can not only provide the chemical components in hot springs but also provide a high-quality reservoir for geothermal resources. However, there is still debate about the main controlling factors and mechanisms of the dissolution process of dolomite. The Shuijing hot springs in Guizhou Province are rich in SO42− and the geothermal reservoir is dolomite, which provides an excellent opportunity to understand the role of SO42− in the dissolution process of dolomite. In this paper, water–rock interaction experiments were conducted at different temperatures to study the effects of SO42−, pH, and CO2 on the dissolution of dolomite from the Shuijing hot springs geothermal reservoir. The results indicate that temperature is a significant factor affecting the chemical composition of hot springs water, with higher temperatures having a more pronounced effect on the dissolution of dolomite. At lower temperatures of 25 °C and 90 °C, the molar ratio of the released Ca2+ and Mg2+ during the dissolution of dolomite in the initial reaction stage generally approaches the Ca/Mg molar ratio of dolomite, exhibiting congruent dissolution. However, at elevated temperatures of 150 °C, the released Ca/Mg molar ratio surpasses the Ca/Mg molar ratio of dolomite, demonstrating an incongruent dissolution characteristic with Ca2+ being preferentially released over Mg2+. Additionally, the relative importance of CO2, SO42− and pH on the dissolution degree of dolomite is CO2 > SO42− > pH = 4 > pH = 7 > pH = 10. The promotion effect of SO42− on dolomite dissolution indicates that the greater the SO42− concentration, the stronger the dissolution of dolomite, and its dissolution ability is enhanced with the increase in temperature. Furthermore, the effect of CO2 on the dissolution of dolomite is stronger than that of SO42−, leading to the oscillating fluctuation trend of the released Ca2+ and Mg2+.

Optimization of physical-chemical water parameters to improve Nile tilapia production performance

The farming of Nile tilapia (Oreochromis niloticus) has shown continuous growth, highlighting the need to optimize production systems to enhance efficiency and sustainability. This study aimed to evaluate the impact of different ionic compositions of water in recirculating systems for tilapia farming. The experiment was conducted at the Aquaculture Laboratory of the Federal University of Grande Dourados (UFGD), in the municipality of Dourados, MS, Brazil, over 51 days, using four water sources with distinct compositions. Parameters such as pH, electrical conductivity, dissolved oxygen, and temperature were monitored. The results indicated that the treatment with the lowest electrical conductivity (T3: 1562 µS/cm) exhibited the best performance in terms of dissolved oxygen (3.93 mg/L) and pH (6.68), providing more stable and favorable conditions for farming. It was observed that higher levels of electrical conductivity and acidic pH in the other treatments compromised water quality stability and productive performance. It is concluded that adjustments in ionic balance are essential to improve recirculation conditions, promoting biosecurity and sustainability in tilapia farming. This study provides practical guidelines for water management, fostering the efficient use of natural resources and environmental preservation, which are fundamental aspects for the sustainable expansion of aquaculture.

Estimation of Soil Evaporation in Apple Orchards Based on Hydrogen and Oxygen Isotopes

Accurate estimation of soil evaporation and plant transpiration is crucial for the scientific and effective management of water resources in apple orchards. Using apple orchards of varying ages as research subjects, the Craig–Gordon model was employed to quantitatively estimate the soil evaporation loss rate, and water balance analysis was utilized to differentiate between soil evaporation and plant transpiration. This study analyzed the effects of extreme precipitation on soil evaporation in apple orchards of varying ages. The results indicated the following: All stable isotopic compositions of soil water fell within the lower right region of the Local Meteoric Water Line, and extreme precipitation reduced the intercept of the Evaporation Trend Line in apple orchards of varying ages. Soil evaporation loss rates in 2021 and 2022 ranged from 13% to 24% and from 14% to 18%, respectively. In 2022, the soil evaporation of apple orchards of 12 y, 15 y, 19 y and 22 y was measured at 123, 77, 129 and 143 mm, respectively, indicating negative correlation (R = −0.75) between soil evaporation and the leaf area index. The corresponding plant transpiration levels were 617 mm, 552 mm, 522 mm and 330 mm, indicating a linear negative correlation between plant transpiration and age (R = −0.92). These results are helpful to guide the scientific development of irrigation systems for apple orchards and provide a reference for enhancing apple yield and promoting the sustainable development of the apple industry.

Региональные особенности формирования ионного стока в бассейне Северной Двины

The article presents the results of assessing the long-term variability of the chemical composition of river waters and ionic runoff in the Northern Dvina River basin. Natural and anthropogenic factors of formation are considered and it is shown that conditions of excessive moisture, cold climate and well-washed podzolic soils led to the formation of waters with low mineralization and a predominance of hydrocarbonates and calcium ions in their composition. The intense anthropogenic impact in the Northern Dvina River basin is due to the presence of a developed forestry complex and the Arkhangelsk agro-industrial agglomeration. The variability of water mineralization and the content of major ions in the river waters of the Northern Dvina River basin appears both along the length of the river itself and between the main tributaries. The highest average long-term values of water mineralization are observed at sections of the Northern Dvina and Vym Rivers, and the lowest one characterizes the Vychegda and Sysola Rivers. Water quality violation in terms of the content of macrocomponents in water occurs sporadically and only in case of maximum concentrations of sulfates (up to 4.0 MAC). The variability of ion runoff is characterized by spatial heterogeneity, and the highest values of runoff modules are typical for a particular River Vym catchment. At the same time, hydrocarbonates and sulfates entering the river network make a major contribution to this variability due to the processes of leaching and washout from the catchment area. The presented results can be used in the development of environmentally sound nature protection measures aimed at improving the environmental situation in the Northern Dvina River basin.

Эколого-географическая характеристика озера Пелёнкино (Ростовская область) по материалам ретроспективных и современных исследований

The physical and geographical characteristics and geological structure of Lake Pelenkino are described. During the analysis of the results of the satellite survey, it was found that the area, length and width of the water surface of the reservoir, as well as the length of the lake's shoreline, the elongation index, and the compactness of the lake vary significantly both by year and by season. It has been suggested that the water surface area and the chemical composition of the water are influenced by both the amount of precipitation and wind-driven effects in the Sea of Azov. The chemical composition of water and mud solution is prone to accumulation of an equivalent amount of Mg2+ relative to Ca2+ over time, which may be due, along with the influence of a hydrological factor, to a change in the physical and chemical equilibrium in the water-mud system. According to the description of the well cores, deposits up to a depth of about 15-35 cm are represented by silt (mud), which first turns into steel-gray clay of a semi-liquid consistency, and then to the bottom of the layer into denser clay. The physical and chemical parameters of the mud of Lake Pelenkino allow us to classify them as continental, silt, mineral, medium mineralized, slightly alkaline, slightly sulfide peloids. Lithological control was found for a set of parameters (pH, Eh, CH4, Ssulfide), which manifests itself in their synchronous change during the transition from silts to the bedrock sediments of the reservoir bed – steel-gray clays. The content of gross mercury in the mud and sediments of the lake does not exceed the threshold of the Low range of Exposure (EQL), equal to 0.15 micrograms/g of dry weight. The bottom sediments of the rivers of the Pelenkino Lake basin and its mud themselves are under anthropogenic influence, which primarily forms a low level of perfringence titer values and its virulence. The use of lake mud for therapeutic purposes without prior preparation is not recommended.

Assessment of Lake Gusinoe Ecosystem Based on Macrophyte Analysis (Republic of Buryatia)

Lake Gusinoye is the largest lake in the Baikal natural territory after Lake. Baikal, around which the Gusnoozersky industrial complex is formed. In the macrophyte flora of the lake. 27 species from 21 families have been identified. The spatial structure of vegetation is determined by the morphometric characteristics of the lake's littoral zone. The northern and southern sectors of the lake are the most overgrown. Compared to previous years of research, an increase in the area of charophyte and moss thickets was revealed. The progressive overgrowing of the lake helps to maintain the processes of self-purification of the ecosystem, removes pollutants and nutrients from circulation and ensures the sustainable development of the ecosystem. The ability of the lake ecosystem to maintain the overall level of productivity due to restructuring of the structure is also evidenced by data on other communities of hydrobionts (zooplankton, zoobenthos and ichthyocenoses). The results of our studies of the chemical composition of macrophytes of Lake. Gusinoe showed, in comparison with the data of the 90s, the concentrations of chemical elements in macrophytes decreased. The recorded ecological state of the lake is determined by a complex of factors, both natural and natural (water level, temperature rise, littoral morphometry, chemical composition of water).

Generation of disinfection byproducts by graphene quantum dot: Graphene nanostructures and water chemistry.

Graphene quantum dot (GQD), as one of the smallest graphene nanomaterials (GNMs), has the potential to be widely used due to its excellent fluorescence properties, hydrophilicity, and good biocompatibility. GQD remaining in water will generate DBPs when entering the disinfection process, and whether the generation mechanism and influencing factors are similar to those of other GNMs has not been proven and thoroughly investigated. In this study, the total amount, effect, and mechanism of DBPs formation from GQD chlorination were investigated and compared with graphene oxide (GO) and graphene. The results show that GQD produced a total trichloromethane (TCM) amount of 1019.6μg/L, which is significantly higher than that produced by GO (99.2μg/L) and graphene (7.0μg/L) at a concentration of 500mg/L. The key factors are abundant functional groups and strong hydrophilicity of GQD after the characterization and comparison of physicochemical properties. Different water chemistry conditions influence DBPs formation, such as Br- increased the formation of brominated DBPs, and high pH led to a decrease in TCM generated by GQD, which is different from other GNMs. However, NaCl concentration can be negligible. Moreover, residual GQD in natural water can participate in the DBPs formation and increase the content of DBPs, which may be influenced by the diversity of chemical composition in surface water. This study highlights the unique impact of GQD on DBPs formation.

Spatiotemporal characterization of the isotopic composition of meteoric waters in Cuba

The stable isotope composition of meteoric water has been widely used to understand hydrological processes worldwide. We present a unique dataset, with the isotopic composition (δ18O and δ2H) of meteoric waters, derived from a nationwide study in Cuba. It includes monthly composite and event-based precipitations, from January 2017 to December 2021 (N = 526 and N = 111 respectively). Monthly data showed minor seasonal trends (dry vs. rainy), with a notable influence of tropical cyclones. Event-based data demonstrated that precipitation associated with tropical cyclones exhibited lower isotopic compositions. The analysis of potential factors influencing the isotopic composition of precipitation showed a minor influence of the rainfall amount, but negligible influence of factors such are relative humidity, elevation, and air temperature. This data set can be used as a tool not only to understand hydrological processes at the country scale, but also to further improve and develop isotope-enabled modelling for assessing water balances and fluxes, understanding the impact of extreme events, and paleoreconstruction in the Intra-Americas Sea.

Содержание химических элементов в костистых лучах плавников Acipenser gueldenstaedtii (Brandt, 1833)

One of the reasons for the decline in the number of sturgeon fish species is the complex ecological situation in the Volga-Caspian basin. Changes in the hydrochemical composition of the Volga-Caspian basin water are accompanied by critical disturbances in the microelement balance of the fish organism and lead to irreversible pathological consequences in the populations of valuable fish species. In order to preserve the population and monitor the condition of sturgeon fish species, a detailed study of the microelement composition of their organs and tissues is necessary. The concentration of chemical elements in the bony rays of the fins of Russian sturgeon Acipenser gueldenstaedtii (Brandt, 1833) of different sexes and age composition (3-10 years) was determined using the atomic absorption method according to GOST 30178-96. Iron, copper, manganese, zinc, nickel, cobalt, chromium, lead, cadmium were determined in each sample. It is noted that all nine studied metals are able to accumulate in sturgeon bone rays to one degree or another. Iron in sturgeon bone rays was present in large quantities relative to other chemical elements. Lead occupied the second place in terms of content in the rays, followed by zinc and cobalt in descending order, and cadmium was found in the lowest concentrations. Copper, zinc, and manganese were shown to have higher metal concentrations in the rays of males, and nickel, chromium, cobalt, lead, and cadmium in the rays of female Russian sturgeon. The differences revealed between the average iron concentrations in the studied organs of females and males of all studied age groups are statistically insignificant. It was noted that with increasing age, weight, and length, the metal content in the bone rays of both males and females increased.

Underwater discharge of fluids at the bottom of lake Baikal: composition, sources and migration peculiarities within the MSU structure

The paper presents geochemical study of bottom sediments from the MSU structure located on the large Gydratny Fault in the Central Basin of Lake Baikal at a depth of 1380 m. The first detailed data on the spatial variations in the qualitative and quantitative composition of the pore waters are presented. Pioneering data were obtained on Li, B, and Sr contents in the pore water of the sediments. It has been established that fluids are actively discharged within the MSU structure, and the main pathways of their near-surface migration are confined to the tops of hills of this structure on the downthrown fault block. The fluids are highly mineralized (up to 2900 mg/L), showing the highest mineralization ever found in Lake Baikal sediments. The waters are significantly enriched in Mg, Li, B, and Sr but depleted in K. The waters are thought to be generated by the processes of authigenic formation and illitization of smectite at depths of 1 to 2.5 km in the sedimentary sequence. The maximum values of concentration gradients are recorded in the pore waters of the sediments of the western hill, which may indicate a gradual westward shift of the center of the fluid seepage activity along the fault.

Biogeochemistry of peat deposits of the Holocene section of the Vydrinsky bog (southern Baikal region)

Drilling cores from peat deposits of the Vydrinsky bog with a thickness of 4.4 m and an age of 13,100 cal. years, composed of lowland, transitional and high-moor types of peat, were studied in detail. The processes of post-sedimentary transformations of swamp sediments during early diagenesis are considered, the distribution of elements, the formation of authigenic minerals and the chemical composition of swamp waters are studied. The destruction of organic matter begins already in the upper intervals of peat at the early stages of diagenesis. Pyrograms do not have clearly defined high-temperature peaks, “rudiments” of the macromolecular structure of kerogen, which indicates a low degree of transformation of peat organic matter. A high number of organotrophic, ammonifying, nitrifying, phosphate-mobilizing microorganisms, a small number of Fe- and Mn-oxidizing microorganisms, and sulfate-reducing bacteria were revealed. The presence of organotrophic microorganisms throughout the section indicates that the biogeochemical processes of the carbon cycle cover the entire thickness of the peat deposit. A small amount of S (II) indicates a low intensity of sulfate reduction processes. Lowland peat is characterized by high contents of Si, Al, Fe, Ca, Sr, Ba, Zr, La and anomalous contents of Cu, Zn, which is a consequence of the formation of the bog under conditions of rich mineral nutrition. In the ash part of the transitional peat, a decrease in the contents of Si, Fe, Sr, Br, K Si, Ca, Ba, Cu, Zn and La is noted, which reflects the gradual weakening of the connection of the peat deposit with the underlying rocks. In the near-surface horizon of high-moor peat, there is an increase in the contents of K, Mn, Zn, Hg, Pb and As, which is associated with an increase in atmospheric dust and anthropogenic impact on the bog ecosystem in the 20th and 21st centuries. Bog waters of low-lying peat are characterized by high contents of the main ions, Al, Fe, Mn, Sr, while transitional peat is characterized by a decrease in DOC, SO42–, HCO3–, Al, Fe, Ni, Ca, Mg. The oligotrophic strata is characterized by the development of Fe oxides and hydroxides, the presence of vivianite is noted for transitional peats, and the eutrophic part of the peat deposit includes rhodochrosite and sulfides of Fe, Cu, and Zn.

Measuring the Stable Isotope Composition of Water in Brine from Halite Fluid Inclusions and Borehole Brine Seeps Using Cavity Ring-Down Spectroscopy.

Naturally occurring bedded salt deposits are considered robust for the permanent disposal of heat-generating nuclear waste due to their unique physical and geological properties. The Brine Availability Test in Salt (BATS) is a US-DOE Office of Nuclear Energy funded project that uses heated borehole experiments underground (∼655 meters depth) at the Waste Isolation Pilot Plant (WIPP) in the bedded salt deposits of the Salado Formation to investigate the capacity for safe disposal of high-level, heat generating nuclear waste in salt. Uncertainties associated with brine mobility near heat-generating waste motivates the need to characterize the processes and sources of brine in salt deposits. Intragranular halite fluid inclusions are a potential source of brine that can migrate under temperature gradients toward heat sources. We developed a methodology to measure the stable isotopic compositions of water (δD VSMOW, δ18 O VSMOW) in brine from halite fluid inclusions using Cavity Ring-Down Spectroscopy that accounts for memory effects using a unique reference-sample-reference bracketing approach and that minimizes sample size requirements. We applied this approach to halite samples obtained from WIPP and compare these data to seeped brines collected from horizontal boreholes at WIPP after drilling at ambient conditions. The stable isotope compositions that we obtain for halite fluid inclusions (δ18 O VSMOW = +3.24 ± 0.53‰, δD VSMOW = -25.3 ± 5.1‰, ±1σ, n = 5) generally agree with previous measurements and likely reflect a combination of syn-depositional and/or postdepositional processes. The seep brines are isotopically distinct (δ18 O VSMOW = +3.46 ± 0.84‰, δD VSMOW = +7.3 ± 3.5‰, ±1σ, n = 35) and instead resemble evaporated seawater. We discuss our results in the context of prior WIPP-proximal waters and lay the groundwork for using stable isotopes of water in brine as a tool to assess the heat-induced mobilization of halite fluid inclusions in ongoing heating experiments that comprise the Brine Availability Test in Salt.

Different Fish Farming Patterns in Paddy Fields Substantially Impact the Bacterial Community Composition, Stability, and Assembly Processes in Paddy Water

Integrated rice–fish farming is an innovative agricultural production pattern that combines rice cultivation with fish farming, enhancing agricultural productivity and ensuring food security. Partitioned rice–fish farming, an advancement of the traditional approach, addresses challenges such as difficulties in fish harvesting and the inconveniences of mechanized operations encountered in paddy fields. To evaluate the environmental impacts of partitioned rice–fish farming on the agricultural ecosystem, we investigated the impacts of partitioned rice–fish farming on the diversity, composition, functionality, co-occurrence networks, and assembly processes of bacterial communities within paddy water. Our results revealed significantly improved Chao1, Observed species, and Pd_faith indices for the bacterial community in the partitioned rice–fish farming system. The relative abundances of the Bacteroidota, Gemmatimonadota, Proteobacteria, and Fluviicola in paddy water were altered by the partitioned system. The partitioned system considerably impacted the bacterial co-occurrence networks within the paddy water, with the planktonic bacterial co-occurrence network in rice cultivation area having more nodes (205) and edges (2085), and its robustness being significantly higher than that of other groups, resulting in a more complex and stable structure of the planktonic bacterial community. In addition, the partitioned system significantly promoted the contribution of stochastic processes to bacterial community assembly in the paddy water, with the main enhanced stochastic processes being homogenizing dispersal and drift. The total proportion of these processes for bacterial community assembly increased from 60% to 70%. Nitrate concentrations in the paddy water were remarkably associated with the water bacterial communities and contributed most to the variations in water bacterial communities. Hence, partitioned rice–fish farming is a feasible and good agricultural production pattern, and from the perspectives of bacterial community diversity and stability it offers both theoretical insights and data-supported foundations for advancing sustainable agricultural practices.

Hydrochemical characteristics of water quality of the Bystrytsia River basin (Lviv region)

The article investigates the hydrochemical composition of water in the Bystrytsia River basin. The ratio of the main water ions was determined and it was found that along the flow the hydrochemical facies of water changes from HCO3-–Ca2+ to HCO3-–Ca2+–Mg2+. River water has an average mineralization, which increases from 391 mg/l to 463 mg/l. The reaction of the environment in the Bystrytsia River basin is mostly slightly alkaline (pH=8.15) and changes to neutral (pH=7.2) in the village of Hrushiv. Permanganate oxidation of river water in the village of Velyka Ozymyna is higher than in other areas and is associated with the presence of lowland peatlands in this area, which are a source of humic acids. A tendency for a gradual increase in phosphates P–PO43- from the river source to its mouth and sudden changes in the concentration of nitrates N–NO3- has been noted. The contamination coefficients of such biogenic elements are less than 1. Ammonium ions, nitrites and many heavy metals (Zn, Mn, Cu, Co, Ni, Pb) were not detected in the river water of the Bystrytsіa river basin. The water in the Bystrytsia River basin corresponds to class 1 according to the water pollution index (very clean, IW=0.02-0.16) and this indicator is 1.8 times lower than in the Dniester River. The increase in the water pollution index along the river is due to increases in the multiplicity of phosphates in the water. The ecological state of water in the Bystrytsia River basin using the complex indicator СPES was determined to be stable with features of instability (CPESmin=-0.61 and CPESav=0.87), instability was detected in the Novoshytska HPP reservoir, in the villages of Zalokot and Urizh. The negative complex indicator of the ecological state of water in these areas corresponds to the sanitary and toxicological indicators (CPES 3) and is due to the influence of magnesium ions, which dominate over Ca2+ ions in river water, form the HCO3- – Mg2+ or HCO3- – Mg2+ – Ca2+ hydrochemical facies and exceed the permissible content. A stable water state with features of instability has been established in the Dniester and Cherkhavka rivers. According to the IZV, the waters are very clean, but have increased mineralization (>500 mg/l), higher hardness (5.8 and 4.7 mmol-eq/l), stronger acidity (pH=7.2 especially in the Dniester), higher permanganate oxidation (4.2 mg O/l mostly in the Dniester), higher concentration of Fe3+ ions (4.9 μg/ml mostly in the Dniester). The hydrochemical composition of the water is different: HCO3- – Ca2+ – Mg2+ in the Dniester and Ca2+– HCO3- – Na+ in the Cherkhavka. These analytical results would be useful for building a hydrological conceptual model that ensures better use of the natural water system in the Bystrytsia River basin. Key words: Bystrytsia River basin; main ions; biogenic components; chemical oxygen demand; water pollution index; water quality assessment by a complex indicator.

Triple oxygen isotopes of lunar water unveil indigenous and cometary heritage

The origin of water in the Earth-Moon system is a pivotal question in planetary science, particularly with the need for water resources in the race to establish lunar bases. The candidate origins of lunar water are an indigenous lunar component, solar wind water production, and the delivery of meteoritic and cometary material. Characterizing the oxygen isotopic composition of water provides information on lunar oxygen sources. The scarcity of lunar water required the development of a high-precision analytical technique for small samples. This method employs stepwise heating, fluorination, and oxygen isotopic measurements using a dual inlet isotope ratio mass spectrometer. The three heating steps were selected based on other extraterrestrial material studies to release loosely bound water that may have been terrestrially contaminated (50 °C), loosely bound water (150 °C), and tightly bound water (as OH) (1,000 °C). This method was applied to a suite of 9 Apollo samples (basalts, breccias, and a regolith), along with terrestrial and meteoritic controls. We present here measurements of the triple oxygen isotopic composition of this water. Our data predominantly show high Δ'17O values (≥ 0‰) for lunar water. These values are consistent with enstatite, ordinary, and CI chondrite-like signatures, although coupling Δ'17O with δ18O forms mixing trends that dominantly overlap enstatite signatures. The other end of the mixing line is in the positive Δ'17O space with cometary δ18O values, providing constraints for cometary Δ'17O between 0.75 to 1.75‰.

Water Activation: The Effect of an Electric Field on the Properties of a Liquid

The article discusses the process of obtaining activated water based on an electric field. Activated water obtained as a result of electrolysis demonstrates unique physico-chemical properties that differ from ordinary water, which opens up new possibilities for use in various sectors of the national economy. The mechanisms of water activation and their effect on the acid-base balance, as well as the stability of activated properties, have been studied. The experimental part presents data on the dependence of the pH of the water on the activation time and the voltage between the electrodes. The results show that an increase in activation time and voltage leads to significant pH changes near the anode and cathode. The problems related to the instability of activated properties and the influence of the composition of the source water are discussed. The work highlights the need for further research to optimize activated water production technology and develop standards for its application.

Solvation Dynamics and Microheterogeneity in Deep Eutectic Solvents.

Deep eutectic solvents have attracted considerable attention due to their unique properties and their potential to replace conventional solvents in diverse applications, such as catalysis, energy storage, and green chemistry. However, despite their broad use, the microscopic mechanisms governing solvation dynamics and the role of hydrogen bonding in deep eutectic solvents remain insufficiently understood. In this article, we present our contributions toward unravelling the micro heterogeneity within deep eutectic solvents by combining vibrational Stark spectroscopy and two-dimensional infrared spectroscopy with molecular dynamics simulations. Our findings demonstrate how the composition, constituents, and addition of water significantly influence the heterogeneous hydrogen bonding network and solvent dynamics within these systems. These insights provide valuable guidance for the design of next-generation solvents tailored to specific applications. By integrating experimental and computational approaches, this work sheds light on the intricate relationship between solvation dynamics and nanostructure in deep eutectic solvents, ultimately paving the way for innovative advances in solvent design.