Basin Water Research Articles

Numerical Analysis to improve the efficiency of a Solar Still (Single-Slope)

Purpose: This study investigates enhancements to maximise the efficiency and performance of the single-slope solar still for sustainable water solutions. Design/Methodology/Approach: This research focuses on the design of a solar still (single-slope) and integration with phase change materials (PCMs), reflective mirrors, and black dye into the solar still (single-slope) to augment its improvement in efficiency. PCMs, such as paraffin wax, are known for their latent heat storage, sustaining higher temperatures within the still to enhance evaporation. Findings: The study found that reflective mirrors amplify solar radiation entry, increasing thermal efficiency. Black dye, added to the basin water, enhances heat absorption, accelerating water evaporation rates. Finally, all improve the efficiency of solar stills (single-slope). Research Limitation: The research uses renewable energy (solar power); therefore, it has been limited to work in the daytime only. Practical Implication: The results show that the insulated basin, PCMs placement at the base, reflective mirrors encircling the still, and black dye in the water significantly improve the efficiency of solar stills (single-slope). Therefore, the quest for sustainable water solutions amid global water scarcity may be achieved through solar still technology, particularly the single-slope solar still. Social Implication: The study endorses the proposed system, which can provide sustainable and reliable water solutions through renewable solar energy as a clean energy. Originality/Value: Comparative analysis with conventional solar still underscored significant performance gains: The enhanced configuration produced an average of 3.04 litres of distilled water daily, a 42% increase over the conventional 2.14 litres. Hourly yield data highlighted peak performance at midday, with the enhanced still yielding 260 mL/hr compared to 180 mL/hr from the conventional.

Water Balance and Climate of the Ipojuca River Water Basin – Pernambuco, Brazil

The objective is to carry out the analysis of the climatic water balance and make a comparison between the municipalities surrounding the Ipojuca River basin, using the applications of climatic indices and aridity. The study area is the Ipojuca River – Pernambuco river basin, made up of twenty-seven municipalities. The rainfall data were provided by the Water and Climate Agency of the State of Pernambuco and thermal data were estimated by the Estima_T software corresponding to the years 1962 to 2018. For the climatic and agricultural suitability analysis, climatic indices of aridity and water availability were applied to the vegetation. The aridity index was calculated using the UNEP formulation, the climatic classifications, using the aridity index or dry month, recommended by Gaussen. Municipalities with higher altitudes provide conditions for better natural development of vegetation followed by greater potential for the development of agricultural activities, when compared to municipalities at lower altitudes. A marked change was observed between the climatic conditions of municipalities with high and low altitudes in the basin area, with emphasis on water deficits and high temperatures. Marked disputes between climate variability in municipalities at higher and lower altitudes were recorded in water deficits and inter-municipal thermal fluctuations.

Spatiotemporal Dynamics of Drought in the Huai River Basin (2012–2018): Analyzing Patterns Through Hydrological Simulation and Geospatial Methods

As climate change intensifies, extreme drought events have become more frequent, and investigating the mechanisms of watershed drought has become highly significant for basin water resource management. This study utilizes the WRF-Hydro model in conjunction with standardized drought indices, including the standardized precipitation index (SPI), standardized soil moisture index (SSMI), and Standardized Streamflow Index (SSFI), to comprehensively investigate the spatiotemporal characteristics of drought in the Huai River Basin, China, from 2012 to 2018. The simulation performance of the WRF-Hydro model was evaluated by comparing model outputs with reanalysis data at the regional scale and site observational data at the site scale, respectively. Our results demonstrate that the model showed a correlation coefficient of 0.74, a bias of −0.29, and a root mean square error of 2.66% when compared with reanalysis data in the 0–10 cm soil layer. Against the six observational sites, the model achieved a maximum correlation coefficient of 0.81, a minimum bias of −0.54, and a minimum root mean square error of 3.12%. The simulation results at both regional and site scales demonstrate that the model achieves high accuracy in simulating soil moisture in this basin. The analysis of SPI, SSMI, and SSFI from 2012 to 2018 shows that the summer months rarely experience drought, and droughts predominantly occurred in December, January, and February in the Huai River Basin. Moreover, we found that the drought characteristics in this basin have significant seasonal and interannual variability and spatial heterogeneity. On the one hand, the middle and southern parts of the basin experience more frequent and severe agricultural droughts compared to the northern regions. On the other hand, we identified a time–lag relationship among meteorological, agricultural, and hydrological droughts, uncovering interactions and propagation mechanisms across different drought types in this basin. Finally, we concluded that the WRF-Hydro model can provide highly accurate soil moisture simulation results and can be used to assess the spatiotemporal variations in regional drought events and the propagation mechanisms between different types of droughts.

Enhancing water productivity of solar still using thermal energy storage material and flat plate solar collector

In this research, the impact of integrating solar still with thermal energy storage material and flat plate solar collector (FPSC) on the freshwater productivity was experimentally investigated. The experiments were conducted on three types of similar-sized solar stills under climate conditions of Saudi Arabia. The first type was a conventional solar still (CSS), without any modifications. The second type was a modified solar still (MSS-1), CSS integrated with natural stones in the still basin. The third type was a modified solar still (MSS-2), CSS integrated with both natural stones and FPSC. Three types of natural stones with same quantity were selected and individually tested in the MSS-1 and MSS-2 simultaneously (each stone type on one day). The corresponding experimental results of MSS-1 showed a 11–32% increase in the daily freshwater yield, compared to CSS, indicating a minimal effect of natural stones utilization on the freshwater productivity. The MSS-2 showed a 155–183% increase in the daily freshwater yield, compared to CSS, indicating a significant effect of basin water heating on the freshwater productivity. The total dissolved solids (TDS) level was measured at 112 ppm, which complies with the permissible limits for drinking water quality standards. The economic analysis revealed that the cost to produce one liter of freshwater is 0.028, 0.022, and 0.027 $ from CSS, MSS-1, and MSS-2, respectively. Additionally, the benefit–cost ratio (BCR) analysis demonstrated the economic feasibility of the constructed solar still, with a BCR value of 2.1.

Will vegetation restoration affect the supply-demand relationship of water yield in an arid and semi-arid watershed?

Natural processes, combined with human activities, determine the inherent quality of regional water supply and demand. However, the interaction between artificial vegetation restoration and water supply-demand dynamics remains insufficiently understood, particularly in arid and semi-arid regions. This study focuses on the Jinghe River Basin (JRB) in the central Loess Plateau, aiming to investigate the changes in supply and demand of ecosystem water yield services and analyze factors affecting the water supply-demand relationship during the vegetation restoration, using the InVEST model, scenario analysis, and the Geodetector. The key findings are as follows: (1) Water shortages in the basin are concentrated in the southern and northern areas, while the southwestern and central areas exhibit water surpluses. Between 2000 and 2020, the water supply showed a first decline and then increase trend, whereas water demand exhibited an opposite trend, with 2009 and 2013 as turning points, respectively. These changes mitigated the basin's water scarcity. (2) Assuming constant meteorological factors and fixed water use indicators, water supply in the vegetation restoration areas decreased by 47.4 million m3, but water demand decreased by 89 million m3, indicating that vegetation restoration did not threaten human water availability. (3) Water supply is primarily influenced by meteorological factors, while water demand and the water supply-demand ratio (WSDR) are mainly driven by socio-economic factors. The influence of precipitation on water yield (q=0.69) outweighs that of land use (q=0.14), indicating that the reduction in water yield due to vegetation restoration is offset by the increased precipitation. This study provides insights into the spatiotemporal dynamics of water yield services and the relationship between vegetation restoration and water supply-demand in the arid and semi-arid regions.

Regional coalition of basin water pollution control based on differential game

Regional coalition of basin water pollution control based on differential game

Analysis of Climate Change Impacts on Water Resources in Harirod-Murghab River Basin

Climate change represents one of the paramount challenges confronting humanity today. The profound impacts of phenomena such as changes in precipitation patterns, global warming, polar ice melt, floods, and the onset of untimely and extreme temperatures worldwide have instilled a sense of urgency and concern. This critical issue has been placed at the forefront of climate change. To understand the ramifications of climate change on water resources within the Harirud-Marghab River basin, an analysis of average precipitation and temperature variations (including minimum, maximum, and average values) across different time frames (annual, monthly, seasonal, and during wet and dry seasons) has been conducted using data from hydrometeorological stations in the catchment area from 1979 to 2022. the non-parametric Mann-Kendall and PCI methods were chosen as the analytical tools. The findings reveal a notable decline in annual rainfall within the Harirud-Marghab River basin, with a pronounced reduction during the winter, the basin's primary water season. Conversely, an increase in seasonal rainfall has been observed in summer and autumn. Overall, rainfall in this river basin tends to be intense, occurring on limited days throughout the year. Furthermore, a significant rise in the annual average temperature has been documented, alongside fluctuations and changes in water flow across most stations within the basin. Consequently, the surface water resources of the Harirud-Marghab River basin have experienced a substantial decrease, amounting to approximately 29% of its capacity, equivalent to a reduction of 0.98 billion cubic meters of water.

Upper Devonian сalcareous algae of the Northern part of the Lviv Paleozoic Trough (systematic composition, facial timing and stratigraphic significance)

As a result of the study of core material in the volume of 211 thin sections from five boreholes of the Northern part of the Lviv Paleozoic Trough, a complex of fossil green, red, and charophyte algae was revealed, which consists of 20 species of 13 genera of green, red, and charophyte algae, among which five species of five genera are identified for the first time for the Devonian deposits of the Lviv Paleozoic Trough. The carbonate deposits belong to the Frasnian and Famennian stages and are represented mainly by sandstones, argillites, siltstones, limestones, dolomites, marls, and white chalk. Carbonate deposits are represented mainly by pelitomorphic wackestones, packstones, wackestone-packstones, grainstones, grainstone-packstones, micrite, bioclastic wackestones, and microbioclastic pelitomorphic wackestones. Limestones often have a pelitomorphic texture, enriched with sand material or dolomitized. The algae are confined primarily to pelitomorphic wackestones of the Waulsortian type, which indicates the intermediate facies of the shelf margins, which were formed by the open circulation of sea waters. To a lesser extent, algae occur in packstones, grainstones, wack-packstones, and are found predominantly along the remains of foraminifera, crinoids, bryozoans, ostracods, and sponge spicules. It is revealed that the algal assemblage of the Famennian stage is depleted and represented mainly by the green tubular algae of the families Palaeoberesellaceae Mamet et Roux and Dasycladaceae Kützing. Higher up the section, a few charophyte algae of the genus Planoumbella Platonov are found. The assemblage of the Famennian stage is significantly enriched, both numerous and systematic. Numerous charophyte and red algae appear, especially in the upper part of the section, which corresponds to the stratigraphic level of the zone C1ta of Donbass. These deposits were considered for a long time to be Tournaisian until at the All-Union Congress in 1986 the Devonian-Carboniferous boundary at the base of the Gattendorfia (Acutimoceras) goniatite zone and the Siphonodella sulcata conodont zone was drawn, which represents the top of the C1ta zone of Donbass. At this level, the richest and most varied algae assemblage is revealed. Above this level, representatives of the genus Parachaetetes Deninger and charophyte algae are not found. The prevalence of the green siphoncladal algae in the Frasnian association indicates a calm hydrodynamic regime below the level of the tide, as well as the depth of the basin, which does not exceed 3-5 m, slight fluctuation in the depth of the sea basin, good illumination, and warm water. The significant distribution of charophyte algae in the Famennian time indicates a decrease in salinity in the paleobasin due to the flow of fresh water from the Kovel uplift.

Coupling and Comparison of Physical Mechanism and Machine Learning Models for Water Level Simulation in Plain River Network Area

In this study, the JiaoGang Basin in the Yangtze River Delta plains of the river network area was the research object. A basin water level simulation model was constructed based on the physical mechanism model and Mike software, and the parameters were calibrated and validated. Based on the dataset produced by the physical model, three types of ML models, Support Vector Machine (SVM), random forest (RF), and gradient boosting decision tree (GBDT), were constructed, trained, validated, and compared with the physical model. The results showed that the physical mechanism model met the water level simulation accuracy requirements at most stations. In the training and validation periods, the RF water level simulation and GBDT water level simulation models had root mean square errors (RMSEs) of all stations less than 0.25 and the Nash–Sutcliffe coefficient (NSE) of all stations was greater than 0.7. The physical mechanism model and ML water level simulation models can simulate the water level in the JiaoGang Basin better. The RF and GBDT models considerably outperform the physical mechanism model in terms of the peak simulation errors and peak present time errors, and the fluctuations of the ML water level simulation models (RMSE and NSE) are minor compared to those of the physical mechanism model.

Water Security of the Kazakhstan-Russia Border River Basins: Kazakhstan’s Perspective

Introduction. The article analyzes water security issues in river basins of the Kazakhstan-Russia border region, as well as transboundary cooperation in this area. These issues are analyzed from a Kazakhstani perspective, which has distinct characteristics compared to the Russian perspective but cannot be considered without taking the latter into account. Methods and materials. The study is based on the concept of water security. For the first time, the northern water basins of Kazakhstan with their transboundary rivers are viewed through the lens of this concept as a single entity with common problems, many of which require solutions at the international level. The study also relies on an analysis of the strengths and weaknesses of Kazakhstan-Russia agreements on transboundary river issues, as well as a quantitative analysis of water levels, pollution, and other characteristics of the relevant water basins. Data obtained from Kazakhstani state institutions, particularly from the state enterprise “Kazhydromet,” are analyzed. Using this data and the ArcGIS program, maps of Kazakhstan’s hydrographic basins were compiled. Analysis. The key security issues of the northern Kazakhstani transboundary water basins, including water scarcity, floods, pollution, and the degradation of biodiversity in coastal areas, are examined. Additionally, the effectiveness of Kazakhstan-Russia cross-border cooperation in addressing these issues is evaluated. Results. In the long term, water scarcity is the most serious challenge to water security, but natural disasters also require serious attention and more effective transboundary cooperation. It would be unjustified to place the primary responsibility on either single side for the water security issues in the region, as both countries have similar infrastructure and inherited economic development priorities from the Soviet era. The effectiveness of Kazakhstan-Russia cooperation in addressing water security issues remains ambiguous: on the one hand, the parties strive to resolve existing problems constructively, but on the other hand, their willingness to undertake coordinated and costly steps is quite limited. Contributions. K. Abdrakhmanov conducted SWOT analysis of empirical issues related to transboundary rivers and (together with S. Golunov) issues of transboundary cooperation between Kazakhstan and Russia; S. Golunov conceptualized the problem of water security, applied it to the empirical parts of the work, and analyzed the issues of floods and threats to biodiversity; M. Muzdybayev collected and analyzed data on hydrography, hydrology, water use, and the environmental state of Kazakhstan’s water basins; Ye. Karakulov and A. Kabdeshev categorized and compiled cartographic material for the hydrographic basins of Kazakhstan using the ArcGIS program.

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.

Biogeochemical and physical properties influencing the nutrient reservoirs of subsurface water in the changing Canada Basin

Biogeochemical and physical properties influencing the nutrient reservoirs of subsurface water in the changing Canada Basin

Date Palm Waste-Derived Biochar for Improving Hydrological Properties of Sandy Soil Under Saturated and Unsaturated Conditions

Water conservation and effective irrigation management are vital for sustainable agriculture in arid regions. While organic soil amendments have been widely used to enhance water retention in sandy soils, research on the use of date palm waste-derived biochar remains limited. Thus, this study aimed to explore the innovative application of biochar produced from date palm waste, focusing on its effects on the hydrological properties of sandy soil. Biochars of varying particle sizes (0.5, 1, and 2 mm) and pyrolysis temperatures (300 °C, 450 °C, and 600 °C) were produced and their impacts were assessed under both saturated and unsaturated conditions on soil hydrological properties. The biochar was incorporated into soil columns at application rates of 0%, 1%, 3%, and 5% (w/w) within a 10 cm layer on top of 35 cm deep soil columns. The soil columns were placed vertically into water basins for saturation. Evaporation, infiltration, and saturated hydraulic conductivity were measured. The findings revealed that the application of 1%, 3%, and 5% biochar significantly increased soil water retention by 36.80%, 34.18%, and 29.66%, while cumulative evaporation decreased by 7.30%, 2.00%, and 1.35%, respectively, as compared to the control. Water retained at the end of the experiment was increased by 100.63%, 112.29%, and 101.68%, while unsaturated hydraulic conductivity decreased by 21.27%, 26.15%, and 26.17% after amending the soil with 1%, 3%, and 5% biochar, respectively, as compared to the control. The water retention ranged between 30.34 and 42.51%, 22.59 and 43.20%, and 22.48 and 38.81% for biochar produced at 300 °C, 450 °C, and 600 °C, respectively. Water infiltration rate and pore size was decreased with the increased pyrolysis temperature. Overall, the application rates of 3% and 5% with particle sizes of 1 and 0.5 mm and low pyrolysis temperature were most efficient for improving soil properties such as water retention, reducing unsaturated hydraulic conductivity, reducing the rate and volume of infiltration, and enhancing the micro-porosity reduction of sandy soils. In a nutshell, this study highlights the potential of date palm waste-derived biochar as an effective soil amendment, significantly enhancing water retention by up to 112.29% and reducing evaporation. By optimizing irrigation management in sandy soils, these findings contribute to more sustainable agricultural practices.

EFFECTS OF ORGANIC CORROSION INHIBITOR SPILLS ON ZOOPLANKTON LIFE IN FRESH WATER BASINS

The paper studies the effect of an organic corrosion inhibitor based on imidazoline in doses from 20 to 100 mg/l on the structural parameters of zooplankton from a freshwater basins. It is known that an increase in temperature can lead to a decrease in food absorption and filtration rate by adults, as well as to egg degeneration and even to their abortion. The flow rate also leads to a decrease in the vital activity process, and the release of cyanobacterial toxins (as well as other nitrogen-containing compounds) also reduces the feeding rate. Besides, these toxins getting into the area increase the weight of the host crustacean, hindering its movement and water filtration. Based on the results obtained, it is important to note that the greatest harm to zooplankton is caused by cyanobacteria and their varieties, the basis of which are nitrogen-containing organic compounds, which are widely used as corrosion inhibitors in oil production. At each stage of the oil production process, there may be (as a result of an accident, etc.) a release of harmful substances into the atmosphere, hydrosphere and lithosphere. When using corrosion inhibitors, there are risks associated with the ingress of inhibitors into fresh water basins. Based on the results of the work, it has been determined that the ingress of even a minimal amount of corrosion inhibitor has a negative effect on the vital activity of zooplankton, reducing the number and biomass. A probable spill of an organic corrosion inhibitor based on imidazoline will negatively affect the qualitative and quantitative characteristics of zooplankton. During the work, no changes were noted in relation to the final number and biomass, which indicates a detrimental effect for each of the dominant taxa presented in the work.

Environmental consequences of maintenance dredging in the port of Sabetta (Gulf of Ob) and compensation measures

In this work, we assess possible negative effects associated with regular maintenance dredging in the port of Sabetta on the marine biological resources and coastal environment of the Gulf of Ob. The costs of environmental protection measures and сountervailing payments are determined. As a restoration activity for fish fauna, it is proposed to implement the artificial reproduction of young fish of valuable species, such as peled, siberian sturgeon, or muksun, followed by their release into the natural environement of the lakes and rivers of the West-Siberian fishery water basin.

Analogs of Precambrian microbial communities formed de novo in Caucasian mineral water aquifers.

The microbiome of deep continental aquifers is considered the most slowly evolving part of the biosphere. The Yessentukskoye Mineral Water Basin (YMWB), located in the pre-Caucasus region, contains three closely spaced but distinct aquifers, the Upper Cretaceous, the Lower Cretaceous, and the Upper Jurassic, which represent unique objects for subsurface biosphere research due to gas-hydrogeochemical and thermal anomalies of the area. We analyzed the geological and hydrogeochemical parameters of the three aquifers and a recharge area of the YMWB and investigated their microbial communities using metagenomic and cultivation-based approaches within a long-term survey. Correlation analysis of the obtained data revealed stable and highly stratified microbial communities inhabiting four distinct ecosystems. Their structure and the metabolic traits of their prokaryotic populations were similar to those presumed to have dominated the Earth's biosphere during several critical periods of its evolutionary history, that is, the Early Archean, the period of banded iron formations accumulation, and the Great Oxidation Event. Among the YMWB strata, the Upper Jurassic aquifer, supersaturated with CO2, influenced by magmatic activity, and highly enriched with thermophilic autotrophic hydrogenotrophic acetogens, turned out to be the first described modern ecosystem based on the primary production by a process predicted to support the Last Universal Common Ancestor (LUCA). The characterization of the YMWB microbial communities reveals a contemporary model environment of the early stages of Earth's development and thus contributes to the understanding of the evolutionary traits in microbial populations that may have played a critical role in the formation of the modern biosphere.IMPORTANCEContinental subsurface environments are estimated to harbor up to one-fifth of the planet's total biomass, representing the most stable and slowly evolving part of the biosphere. Among the deep subsurface inhabitants, the microbial communities of drinking mineral waters remain the least studied. Our interdisciplinary study of the Yessentukskoye Mineral Water Basin shows how hydrochemical and hydrodynamic factors shape different subsurface ecosystems, whose microbial populations influence the composition of mineral waters. A comprehensive analysis reveals the similarity of these ecosystems to those predicted for the early Earth. The deepest of the studied aquifers is the first described modern ecosystem with the most probable primary producer performing hydrogenotrophic acetogenesis. Thus, our results contribute to the understanding of the genesis of modern drinking water resources and expand the knowledge of the evolutionary traits that may have played a critical role in the formation of the Earth's biosphere.

Spatial Distribution, Source Analysis, and Risk Assessment of Multiple Antibiotics in Chaohu Lake Basin

Chaohu Lake is the fifth largest freshwater lake in China that meets the needs of surrounding industries for water, tourism, and flood storage, making it important for the socio-economic development and modernization of Anhui Province. As an important ecological wetland in the lower reaches of the Yangtze River, many rare bird habitats are present along the coast of Chaohu Lake. Therefore, it is eco-economically important to study antibiotic pollution in Chaohu Lake. To unveil antibiotic contamination in Chaohu Lake, surface water and sediment samples were collected from the main basin of Chaohu Lake by steamship in June 2022. Solid phase extraction and ultra-performance liquid chromatography-mass spectrometry （SPE-UPLC-MS） was used to determine the occurrence of 31 target antibiotics, including tetracyclines, sulfonamides, macrolides, and quinolones. The study focused on the spatial distribution, source analysis, and risk assessment of various antibiotics in the surface water and sediments of the main basin of Chaohu Lake. The occurrences of 20 different antibiotics were successively identified in the surface water and sediments of Chaohu Lake. These antibiotics included sulfonamides, quinolones, macrolides, tetracyclines, and others. Significant spatial differences in antibiotics were found between surface water and sediments. The horizontal spatial distribution results indicated differences in species and concentration of antibiotics in surface water and sediments. The vertical spatial distribution results showed that many types of antibiotics had consistent vertical distribution characteristics in surface water and sediments at the same point. The principal component analysis results indicated that the source of antibiotics in surface water was similar to that in sediment and considered with the actual distribution of existing industries around Chaohu Lake； the main sources were livestock and poultry breeding sewage, aquaculture sewage, and household sewage. The ecological risk quotient （RQ） results indicated that norfloxacin in the surface water of Chaohu Lake posed a high risk to algae （RQ > 1）, while sulfamethoxazole and doxycycline posed a medium risk to algae （0.1 ≤ RQ < 1）. The health risk quotient （HRQ） showed that the risk of exposure to antibiotics through drinking water was very low （HRQ < 0.01）. Our findings provide scientific support for decision makers to control antibiotic pollution and reduce the management costs of antibiotic watershed pollution.

Water Recovery of brine water treatment from a small-scale desalination system in Nakhon Ratchasima

This study aims to recover water from treating brine water of a small-scale desalination using a solar still. The design focuses on keeping temperatures inside at conditions suitable for water evaporation from the brine water basin. Water vapor rises and condenses into water droplets on the transparent glass cover, moving down the slope into a channel and collecting outside. The solar still is 1.0 m x 1.0 m x 0.5 m (width x depth x height) with a 25-degree slope for a transparent glass cover on top. This slope allows the water droplet to move down without reentering into the brine water basin below. The brine water was placed on top of the carbonized rice hull. The black residues can absorb heat energy by being a dark color, locally available, environmentally friendly, and stable. The test results during rainy and early winter months showed that the prototype solar still produced the average recovery water of 150 mL/day/set, with the hourly temperatures inside the chamber ranging from 30 to 70.1 Celsius. The highest inside temperature occurred at 2 PM, with an average of 70.1 Celsius. A correlation was observed between temperature and the amount of distilled water. Water recovery from the prototype ranged from 1,090 to 1,256 mL/day. Low recovery occurred in the rainy months. Estimation of water recovery rates in Nakhon Ratchasima ranged from 45 to 55 mL/m2/day. The solar still provides an alternative to recover water and mitigate the direct impact of brine water discharge from the small-scale desalination in Nakhon Ratchasima from possible effect of salinity water discharge. The method is economical, less burdensome to the caretaker, and low budget. The recovery water is freshwater; thus, it can be reused and has no long-term impact. The use of solar still is an auxiliary device that can be used with small-scale desalination in areas with saline water.

Hydrogeochemical characteristics and evolution of formation water in the continental sedimentary basin: A case study in the Qaidam Basin, China.

In deep formations, oil or gas reservoir rocks are generally accompanied by groundwater with high total dissolved solids (TDS), commonly referred to as "formation water". The enrichment of trace and/or metallic elements such as K, B, Li, Br, Sr in this type of groundwater holds significant industrial values and socioeconomic benefits. However, the processes involved in the burial and generation of formation water remain not fully understood. In this study, totally 468 sets of major ions and trace elements were collected from current study and literatures to investigate the hydrogeochemical characteristics and evolution mechanisms of formation water from different regional geological structure units in Qaidam Basin, China. The results indicated that TDS of formation water in Western (QW), Central (QC) and Northern (QN) units of Qaidam basin ranged from 173 to 290g/L, 101 to 152g/L and 32 to 73g/L, respectively, which were several to dozens of times higher than those of seawater, but lower than those of intercrystalline brine and salt lake water. The enrichment of Ca, Li, B, Br and depletion of Mg and SO42- were observed in the formation water in comparison to seawater and salt lake water. Formation water especially in QC and QW was identified as typical dissolved brine of terrestrial rock origin, experiencing prolonged water-rock interactions. However, the time and degree of water-rock interaction and metamorphism differed regionally due to the sedimentary history and patterns of Qaidam Paleolake. Overall, the large paleolake deposits under the control of multiple tectonic movements laid the material foundation for the burial and generation of the formation water, and a variety of fluids and deep faults became the sources and migration channels for formation water. It mainly experienced two stages, including the sedimentary process of saline strata and the transformation in the later period.

Bridging the gap: an interpretable coupled model (SWAT-ELM-SHAP) for blue-green water simulation in data-scarce basins

Blue water (BW) and green water (GW) are crucial components of the hydrological cycle, but their accurate simulation and interpretation remain challenging in data-scarce basins. We propose the SWAT-ELM-SHAP model, coupling the Soil and Water Assessment Tool (SWAT), Ensemble Learning Model (ELM), and Shapley Additive Explanations (SHAP) method. This novel approach bridges the gap between a physically-based hydrological model, a data-driven machine learning (ML) model, and a holistically-interpreted SHAP method, offering accurate blue-green water simulation and holistic result interpretation for improved water resources management in data-scarce basins. We took the transfer simulation of blue-green water from the Xiangjiang River Basin (source basin, 82,900km²) to the Zishui River Basin (target basin, 28,142km²) as a case study to test and evaluate the feasibility of the coupled model during 1991-2022. The model performance results indicate that the simulation accuracy of our new coupled model is improved in data-scarce basins. In combination with hydrological response features generated by SWAT and meteorological features as the ELM input, our model enhances the daily blue-green water simulation. The Nash-Sutcliffe Efficiency coefficient (NSE) for BW, Green water flow (GWF), and Green water storage (GWS) consistently exceeds 0.77 during the calibration period (1991-2010) and exceeds 0.8 during the testing period (2011-2022). The interpretation results of coupled model demonstrate that SHAP holistic interpretation provides good interpretability for blue-green water simulation results in data-scarce basins. In general, the SWAT-ELM-SHAP offers a referenced approach that can reliably and efficiently simulate blue-green water in data-scarce basins, but more importantly, can further our understanding of the potential causal relationships, influence mechanisms, and variation mechanisms of blue-green water under changing environmental conditions.