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Groundwater, as an essential resource, holds significant importance for human production and livelihoods. With the deterioration of the water environment, the issue of groundwater quality has become an urgent international concern. This study focused on the Fenghuang Mountain Area (FMA) and collected a total of 41 sets of samples including pore groundwater (PGW), fissure groundwater (FGW), karst groundwater (KGW), and river water (RW). Hydrochemical analysis methods were employed to identify the hydrochemical characteristics and controlling factors. The entropy-weighted water quality index (EWQI) and health risk assessment model were utilized to assess the groundwater quality and nitrate health risk, respectively. The results indicated that the dominant anion and cation in both groundwater and surface water in the FMA were HCO 3 - and Ca 2+ , respectively, with the main hydrochemical type being HCO 3 concentration closely related to human activities. The water quality of FGW was relatively good, with Class I and Class II water accounting for the highest proportion, reaching 84.62%. The high-value area of EWQI in PGW was influenced by human activities. The impact of nitrate health risk on children was significantly greater than on adults, with FGW having the lowest health risk and PGW having the highest health risk. The research results can provide important guarantees for the rational development and utilization of water resources in the FMA and the sustainable development of the economy in Northeast China.3 - concentration closely related to human activities. The water quality of FGW was relatively good, with Class I and Class II water accounting for the highest proportion, reaching 84.62%. The high-value area of EWQI in PGW was influenced by human activities. The impact of nitrate health risk on children was significantly greater than on adults, with FGW having the lowest health risk and PGW having the highest health risk. The research results can provide important guarantees for the rational development and utilization of water resources in the FMA and the sustainable development of the economy in Northeast China., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Renowned for its agriculture, livestock, and mining, Zhob district, Pakistan, faces the urgent problem of declining groundwater quality due to natural and human-induced factors. This deterioration poses significant challenges for residents who rely on groundwater for drinking, domestic, and irrigation purposes. Therefore, this novel study aimed to carry out a comprehensive assessment of groundwater quality in Zhob district, considering various aspects such as hydrochemical characteristics, human health risks, and suitability for drinking and irrigation purposes. While previous studies may have focused on one or a few of these aspects, this study integrates multiple analyses to provide a holistic understanding of the groundwater quality situation in the region. Additionally, the study applies a range of common hydrochemical analysis methods (acid-base titration, flame atomic absorption spectrometry, and ion chromatography), drinking water quality index (WQI), irrigation indices, and health risk assessment models, using 19 water quality parameters. This multi-method approach enhances the robustness and accuracy of the assessment, providing valuable insights for decision-makers and stakeholders. The results revealed that means of the majority of water quality parameters, such as pH (7.64), electrical conductivity (830.13 μScm -1 ), total dissolved solids (562.83 mgL -1 ), as well as various anions, and cations, were in line with drinking water norms. However, the water quality index (WQI) predominantly indicated poor drinking water quality (range = 51-75) at 50% sites, followed by good quality (range = 26-50) at 37% of the sites, with 10% of the sites exhibiting very poor quality (range = 76-100). For irrigation purposes, indices such as sodium percent (mean = 31.37%), sodium adsorption ratio (mean = 0.98 meqL -1 ), residual sodium carbonate (- 3.15 meqL -1 ), Kelley's index (mean = 0.49), and permeability (mean = 49.11%) indicated suitability without immediate treatment. However, the magnesium hazard (mean = 46.11%) and potential salinity (mean = 3.93) demonstrated that prolonged application of groundwater for irrigation needs soil management to avoid soil compaction and salinity. Water samples exhibit characteristics of medium salinity and low alkalinity (C2S1) as well as high salinity and low alkalinity (C3S1) categories. The Gibbs diagram results revealed that rock weathering, including silicate weathering and cation exchange, is the primary factor governing the hydrochemistry of groundwater. The hydrochemical composition is dominated by mixed Ca-Mg-Cl, followed by Na-Cl and Mg-Cl types. Furthermore, the human health risk assessment highlighted that fluoride (F - ) posed a higher risk compared with nitrate (NO 3 - ). Additionally, ingestion was found to pose a higher risk to health compared to dermal contact, with children being particularly vulnerable. The average hazard index (HI) for children was 1.24, surpassing the allowable limit of 1, indicating detrimental health effects on this subpopulation. Conversely, average HI values for adult females (0.59) and adult males (0.44) were within safe levels, suggesting minimal concerns for these demographic groups. Overall, the study's interdisciplinary approach and depth of analysis make a significant contribution to understanding groundwater quality dynamics and associated risks in Zhob district, potentially informing future management and mitigation strategies., (© 2024. The Author(s).)

An in-depth understanding of nitrate-contaminated surface water and groundwater quality and associated risks is important for groundwater management. Hydrochemical characteristics and driving forces of groundwater quality and non-carcinogenic risks of nitrate were revealed by the integrated approaches of self-organizing map analysis, spatial visualization by geography information system, entropy and irrigation water quality indices, and human health risk model. Groundwater samples were categorized into two clusters by SOM analysis. Cluster I including three samples were Ca-SO 4 type and cluster II of remaining 136 samples were Ca-HCO 3 type. Hydrochemical compositions of two cluster samples were dominated by water-rock interaction: (1) calcite and gypsum dissolution for cluster I samples and (2) calcite dissolution, silicate weathering, and positive cation exchange for cluster II samples. Nitrate contamination occurred in both cluster I and II samples, primarily induced by agricultural nitrogen fertilizer. The EWQI results showed that 90.97% in total groundwater samples were suitable for drinking purpose, while the IWQI results demonstrated that 65.03% in total groundwater samples were appropriate for irrigation purpose. The HHR model and Monte Carlo simulation indicated that the non-carcinogenic nitrated risk was highest in children. Exposure frequency was the most sensitive factor (86.33% in total) influencing the total non-carcinogenic risk, indicated by sensitivity analysis. Compared with the two clusters of groundwater, surface water has a shorter circulation cycle and lower ion concentrations resulting in better water quality. This study can provide scientific basis for groundwater quality evaluation in other parts of the world., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Owing to increasing anthropogenic impacts, wetlands have suffered a serious environmental decline in recent decades. The sustainable management of these natural resources is fundamental to maintain both the ecosystems and the economic activities. The Lake Massaciuccoli and nearby areas represent one of the largest residual coastal marshy areas in Tuscany (Italy). This wetland is characterized by large-scale and intensive agricultural use and affected by reclamation activities, with consequent problems of erosion, subsidence and lake eutrophication and siltation. In this context, an integrated study combining hydrochemical data (water levels, electrical conductivity, pH, turbidity, major ions, trace metals) and stable isotopes (H, O, S) has been performed in the southernmost part of the basin, to better disentangle processes and interactions between groundwater and surface water and to understand the origin of solutes and their evolution. Our results indicated that both groundwater and surface water have a meteoric origin and that geochemical composition of groundwater is mainly affected by local geological and biological processes. Moreover, surface water is affected by sea water mixing and evapotranspiration/precipitation processes. The impact of agricultural activity and the use of fertilizers on the water quality appears to be limited as regards nitrates, indicating that less intense agricultural practices implemented in recent years have been successful. As regards sulfates, Fe, and Mn, we cannot fully elucidate the mechanisms underlying human influence, but the oscillation of water level and degradation of peat enhanced by reclamation and agriculture activities likely played an important role in controlling the fate of these elements. Overall, these results underline the importance of integrated approaches to disentangle geochemical processes and will be useful in supporting policy implementation and environmental protection in this valuable area of Tuscany. Findings from this work suggest the need for policy-making authorities to take actions as soon as possible to mitigate risks. Closer co-operation is essential between authorities and farmers to reduce inputs of fertilizers and chemicals into the lake and the surrounding area. Also, additional policy measures should be enforced to reduce the mechanical soil tillage and limit erosion and runoff, such as the NBSs implemented within the Phusicos Project., (© 2024. The Author(s).)

In this study, twenty-two water samples were collected from boreholes (BH), and streams to evaluate drinking water quality, its distribution, identification of contamination sources and apportionment for Moti village, northern Pakistan. An atomic absorption spectrophotometer (AAS) is utilized to determine the level of heavy metals in water such as arsenic (As), zinc (Zn), lead (Pb), copper (Cu), cadmium (Cd), manganese (Mn), and ferrous (Fe). Groundwater chemistry and its quantitative driving factors were further explored using multivariate statistical methods, Principal Component Analysis (PCA) and Positive Matrix Factorization (PMF) models. Finally, a total of eight electrical resistivity tomographs (ERTs) were acquired across i) the highly contaminated streams; ii) the villages far away from contaminated streams; and iii) across the freshwater stream. In the Moti village, the mean levels (mg/l) of heavy metals in water samples were 7.2465 (As), 0.4971 (Zn), 0.5056 (Pb), 0.0422 (Cu), 0.0279 (Cd), 0.1579 (Mn), and 0.9253 (Fe) that exceeded the permissible limit for drinking water (such as 0.010 for As and Pb, 3.0 for Zn, 0.003 for Cd and 0.3 for Fe) established by the World Health Organization (WHO, 2008). The average entropy weighted water quality index (EWQI) of 200, heavy metal pollution index (HPI) of 175, heavy metal evaluation index (HEI) of 1.6 values reveal inferior water quality in the study area. Human health risk assessment, consisting of hazard quotient (HQ) and hazard index (HI), exceeded the risk threshold (>1),indicating prevention of groundwater usage. Results obtained from the PCA and PMF models indicated anthropogenic sources (i.e. industrial and solid waste) responsible for the high concentration of heavy metals in the surface and groundwater. The ERTs imaged the subsurface down to about 40 m depths and show the least resistivity values (<11 Ωm) for subsurface layers that are highly contaminated. However, the ERTs revealed relatively high resistivity values for subsurface layers containing fresh or less contaminated water. Filtering and continuous monitoring of the quality of drinking water in the village are highly recommended., Competing Interests: Declaration of competing interest All authors have read contents of current manuscript and approved. There is not conflict of interest., (Copyright © 2023. Published by Elsevier B.V.)

The present study aims to evaluate the groundwater quality in an area characterized by significant human anthropic activities within the upper Seybouse. In order to assess the quality, a total of 20 samples were analyzed to identify the chemical and bacteriological composition of the water, its variations, and their potential impacts on the environment and human health. The results revealed concentrations of the chemical and bacteriological elements exceeding the WHO standards, with high levels of electrical conductivity (EC) (peak = 4210 μS/cm), Ca 2+ (peak = 340.68 mg/L), Na + (peak = 360 mg/L), HCO 3 - (peak = 287 mg/L), Cl - (peak = 542 mg/L), SO 4 2- (peak = 687 mg/L), NO 3 -Ca type. The calculated Water Quality Index (WQI) indicates that none of the groundwater samples are suitable for drinking or human consumption. The detection of pathogenic microorganisms through diverse molecular methods has revealed the existence of eight distinct species, encompassing pathogenic strains that can affect human health. Moreover, the dissolution of geologic formations can influence the water's chemistry. In this region, groundwater pollution seems to be influenced by anthropogenic and agricultural factors such as fertilizer application, irrigation practices, and the release of domestic sewage.- (pek = 65.91 mg/L), fecal coliforms (FC) (peak = 160 UFC/mL), fecal Streptococcus (FS) (peak = 43 UFC/mL), and Clostridium perfringens (CP) (peak = 29 UFC/mL). Within the basin, two different facies have been identified: Cl-SO 4 -Na type and Cl-SO 4 -Ca type. The calculated Water Quality Index (WQI) indicates that none of the groundwater samples are suitable for drinking or human consumption. The detection of pathogenic microorganisms through diverse molecular methods has revealed the existence of eight distinct species, encompassing pathogenic strains that can affect human health. Moreover, the dissolution of geologic formations can influence the water's chemistry. In this region, groundwater pollution seems to be influenced by anthropogenic and agricultural factors such as fertilizer application, irrigation practices, and the release of domestic sewage., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

This study assessed the human footprint on the chemical pollution of Antarctic waters by characterizing inorganic chemicals and selected organic anthropogenic contaminants of emerging concern (CECs) in inland freshwater and coastal seawater and the associated ecotoxicological risk. Nicotine and tolytriazole, present in 74% and 89% of the samples analyzed, respectively, were the most ubiquitous CECs in the investigated area. The most abundant CECs were citalopram, clarithromycin, and nicotine with concentrations reaching 292, 173, and 146 ng/L, respectively. The spatial distribution of CECs was not linked to any water characteristic or inorganic component. The contamination pattern by CECs in inland freshwater varied among locations, whereas it was very similar in coastal seawater. This suggests that concentrations in inland freshwater may be ruled by environmental processes (reemission from ice, atmospheric deposition, limited photo- and biodegradation processes, etc.) in addition to human activities. Following risk assessment, citalopram, clarithromycin, nicotine, venlafaxine, and hydrochlorothiazide should be considered of concern in this area, and hence, included in future monitoring of Antarctic waters and biota. This work provides evidence on the fact that current measures taken to protect the pristine environment of Antarctica from human activities are not effective to avoid CEC spread in its aquatic environment., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Evidence from increasing mineralization, micropollutant concentrations, waterborne epidemics, an algal boom, and dissolved organic matter has provided substantial evidence that climate change impacts water quality. While the impact of the extreme hydrological event (EHE) on water quality (WQ) has aroused considerable research interest, research uncertainty has been premised on WQ data scarcity, a short time frame, data non-linearity, data structure, and environmental biases on WQ. This study conceptualized a categorical and periodic correlation using confusion matrices and wavelet coherence for varying standard hydrological drought index (SHDI; 1971-2010) and daily WQ series (1977-2011) of four spatially distinct basins. By condensing the WQ variables using chemometric analyses, confusion matrices were assessed by cascading the SHDI series into 2-, 3-, and 5-phase scenarios. 2-phase revealed an overall accuracy (0.43-0.73), sensitivity analysis (0.52-1.00), and Kappa coefficient (- 0.13 to 0.14), which declines substantially with the phase increase, suggesting the disruptive impact of EHE on WQ. Wavelet coherence depicted the substantial ([Formula: see text]) mid- and long-term (8-32 days; 6-128 days) co-movement of streamflow over WQ, confirming the varying sensitivity of WQ variables. Land use/land cover mapping and the Gibbs diagram corroborate the eventful WQ evolution by EHE and their spatial variability concerning landscape transformation. Overall, the study deduced that hydrologic extreme triggers substantial WQ disruption with dissimilar WQ sensitivity. Consequently, suitable chemometric indicators of EHE impacts such as WQ index, nitrate-nitrogen, and Larson index at designated landscapes were identified for extreme chemodynamics impact assessment. This study proffers a recommendation for monitoring and managing the impact of climate change, floods, and drought on water quality., (© 2023. The Author(s).)

The water quality of Himalayan rivers and streams is deteriorating due to multitude of anthropogenic and natural influences and the changes are more pronounced in smaller hill basins with high human influx. Inadequate data and lack of monitoring further exacerbate the situation. The surface water quality of one such hill stream, Neeru was evaluated for potability and irrigation quality. The water quality parameters were analysed at 25 sampling stations over a stretch of 30 km across four seasons during a 2-year study from January 2014 to December 2015. The CCME Water Quality Index (WQI) indicated excellent water quality in upstream stations, while the midstream and a few downstream stations revealed varying degrees of impaired water quality. Although the irrigation quality of the stream was excellent, pollution levels near urban areas were rather high, necessitating considerable treatment for human consumption. The factor analysis yielded seven components with Eigenvalues greater than one that accounted for 83.656% of the variance and enabled the grouping of selected parameters based on comparable characteristics. The hydrogeochemical characteristics of the water samples indicated that they lie within the zone of rock dominance, while the trilinear diagram depicted the Ca-bicarbonate rich stream water. The study concluded that the upstream stations revealed pristine water quality, which significantly degraded towards human settlements. It thus calls for regular and long-term monitoring of the surface water quality to ensure the continuous and sustainable use of this important water body., (© 2022. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

The study region comprises fractured granitic, basaltic and lateritic aquifer system constituted by Precambrian rocks. Groundwater is the primary source for drinking and household needs. Its quality is a big issue in the three aquifers, which are mostly of human health concern. Many developing regions suffer from lack of safe drinking water, thereby health problems arise in many parts of the regions, and Telangana state is one of them. For this reason, 194 groundwater samples were collected and analyzed for fluoride, nitrate, chloride and other physicochemical parameters. The concentrations of fluoride (F - ), nitrate (NO 3 - ), magnesium (Mg 2+ ), total dissolved solids and total hardness are above the acceptable limits for drinking purposes, prescribed by the World Health Organization. The higher concentrations of fluoride and nitrate in drinking water cause health hazards, and above 50% of the groundwater samples are not suitable for drinking purposes with respect to fluoride and nitrate. Weathering of rocks and dissolution of fluoride-bearing minerals can be a cause for higher fluoride concentrations, while anthropogenic sources are one of the major reasons for higher nitrate concentrations in the study area. Groundwater suitability for irrigation suggests that more than 90% of the groundwater sampling locations are suitable for irrigation. In addition, health risk assessments were evaluated by using the United States Environmental Protection Agency model, to determine the non-carcinogenic risk of fluoride and nitrate in drinking water for adults (females and males) and children. The ranges of hazard index in all sampling locations are varied from 0.133 to 8.870 for males, 0.146 to 10.293 for females and 0.419 to 29.487 for children, respectively. The health risk assessment results indicated that children were more exposed to health risk, due to the intake of high contaminated drinking water with respective of nitrate and fluoride in the study region.

Springs are an important source of drinking water supply in mountainous karst areas of SW China. However, the quality of many spring waters has deteriorated greatly in recent years, which leads to a significant problem of drinking water scarcity. In this study, hydrochemistry and stable sulfur and oxygen isotopic compositions of SO 4 2- (δ 34 S and δ 18 O SO4 ) of 38 representative samples of waters (incl. spring water, surface water, rainwater, and sewage) from the Hongjiadu Basin, Guizhou province, SW China, were investigated in order to identify the sources of contaminates in spring waters and trace the processes affecting the karst groundwater quality. Approximately 28% of the total investigated springs has been suffered from serious contamination and the concentrations of NO 3 - , SO 4 2- , and total iron (TFe) in many spring waters have exceeded the standards for drinking water. The springs that have NO 3 - concentrations of > 30 mg/L are concentrated in residential and agricultural areas, suggesting that NO 3 - in spring water are mainly derived from chemical fertilizers, manure, and sewage. δ 34 S and δ 18 O SO4 data indicate that SO 4 concentrations of > 250 mg/L, demonstrating that mining activities have accelerated the deterioration of spring water quality. Also, springs with TFe concentrations of > 0.3 mg/L are discharged from coal-bearing strata, revealing that iron in spring waters is mainly derived from the oxidation of pyrite. Our results show that the karst spring waters are highly vulnerable to anthropogenic contaminations and human activities, such as agricultural fertilizing and sewage and waste disposal as well as mining activities, which exert a great impact on the quality of groundwater in karst areas.2- in spring water mainly originates from sulfide oxidation, acid rain, and sewage. Furthermore, the high δ 34 S and δ 18 O SO4 values of SO 4 2- in some spring waters may be related to the occurrence of bacterial sulfate reduction. Some springs that are discharged from abandoned coal mines have SO 4 2- concentrations of > 250 mg/L, demonstrating that mining activities have accelerated the deterioration of spring water quality. Also, springs with TFe concentrations of > 0.3 mg/L are discharged from coal-bearing strata, revealing that iron in spring waters is mainly derived from the oxidation of pyrite. Our results show that the karst spring waters are highly vulnerable to anthropogenic contaminations and human activities, such as agricultural fertilizing and sewage and waste disposal as well as mining activities, which exert a great impact on the quality of groundwater in karst areas.

The physicochemical parameters of groundwater in 12 cluster boreholes in Enugu North district/region, southeast Nigeria, were studied. Twelve physicochemical parameters were determined in triplicates at monthly intervals for 3 months in dry season and then repeated in rainy season in 120 boreholes grouped into 12 clusters for 2 years. The range of values obtained during dry season include phosphate (0.12-0.87 mg/L), nitrate (1.24-8.72 mg/L), sulfate (20.10-24.34 mg/L), pH (4.9-7.5), E.C. (10.0-410.0 μS/cm), total acidity (0.06-1.24 mg/L), total alkalinity (28.0-22.10 mg/L), total hardness (100.0-140.1 mg/L), TSS (70.0-270.0 mg/L), TDS (0.00-210.0 mg/L), TS (70.0-390.0 mg/L), and turbidity (3.4-50.0 mg/L) while rainy season values were phosphate (0.30-10.60 mg/L), nitrate (1.20-120.0 mg/L), sulfate (0.0-100.0 mg/L), pH (4.9-7.5), E.C. (10.0-360.0 μS/cm), total acidity (0.10-10.5 mg/L), total alkalinity (10.0-52.1 mg/L), total hardness (100-130 mg/L), TSS (100.0-280.0 mg/L), TDS (0.0-260.0 mg/L), TS (110.0-560.0 mg/L), and turbidity (3.80-56.0 mg/L). When compared with standard guideline values recommended by regulatory bodies, rainy season nitrate values in some samples and phosphate mean values were higher than recommended values. Seasonal variations of the parameters in the samples were observed. Statistical analysis showed statistically significant variations between the 12 borehole water physicochemical parameters in dry and rainy seasons. Water quality index (WQI) analysis categorized all the water samples within the range of good to excellent.

This case study examines the geological imprint and land use practices on water quality in the arid Huasco Valley against the backdrop of ongoing water conflicts surrounding competing demands for agriculture and mining. The study is based on a detailed analysis of spatial and temporal variations of monthly surface and bi-monthly groundwater quality samples measured during the Chilean summer of 2015/16. Additional information on source regions and river-groundwater interactions were collected using stable water isotopes. Regarding the geological impact on water quality, high concentrations of Ca 2+ , SO 4 2- indicate a strong influence of magmatic rocks, which constitute this high mountain basin, on the hydrochemistry. Piper and Gibbs-diagrams revealed that all samples show a homogenous distribution dominated by rock-water interactions. Measured NO 3 - indicate a strong influence of magmatic rocks, which constitute this high mountain basin, on the hydrochemistry. Piper and Gibbs-diagrams revealed that all samples show a homogenous distribution dominated by rock-water interactions. Measured NO 3 - concentrations in surface water are generally low. However, groundwater aquifers exhibit higher concentrations. Mn is the only heavy metal with elevated concentrations in surface water, which are possibly related to mining activities. The results illustrate that both surface and groundwater can be classified as suitable for irrigation. In addition, groundwater has been found to be suitable as drinking water. High similarities in isotopic signatures indicate a strong connection between surface and groundwater. Isotopic analyses suggest a strong influence of evaporation. This combined approach of hydrogeochemical and isotopic analysis proved to be a helpful tool in characterizing the catchment and can serve as a basis for future sustainable water management.

Globally, groundwater resources are being deteriorated by rapid social development. Thus, there is an urgent need to assess the combined impacts of natural and enhanced anthropogenic sources on groundwater chemistry. The aim of this study was to identify seasonal characteristics and spatial variations in anthropogenic and natural effects, to improve the understanding of major hydrogeochemical processes based on source apportionment. 34 groundwater points located in a riverside groundwater resource area in northeast China were sampled during the wet and dry seasons in 2015. Using principal component analysis and factor analysis, 4 principal components (PCs) were extracted from 16 groundwater parameters. Three of the PCs were water-rock interaction (PC₁), geogenic Fe and Mn (PC₂), and agricultural pollution (PC₃). A remarkable difference (PC₄) was organic pollution originating from negative anthropogenic effects during the wet season, and geogenic F enrichment during the dry season. Groundwater exploitation resulted in dramatic depression cone with higher hydraulic gradient around the water source area. It not only intensified dissolution of calcite, dolomite, gypsum, Fe, Mn and fluorine minerals, but also induced more surface water recharge for the water source area. The spatial distribution of the PCs also suggested the center of the study area was extremely vulnerable to contamination by Fe, Mn, COD, and F - ., Competing Interests: The authors declare no conflict of interest.

The present study was carried out to determine the hydrogeochemical processes and the impact of tanning industries on groundwater in Ambur, Vellore district, Tamil Nadu, India. Thirty groundwater samples were collected during pre monsoon (July 2015) and post monsoon (January 2016) from the open and shallow wells around this region and were analyzed for major ions and chromium. The major ion concentration follows the order of Na + > Ca 2+ > Mg 2+ > K + (cations) and Cl - > HCO 3 - > SO 4 2- > NO 3 - (anions) for both seasons. The high concentrations of Na + , Cl - , and Cr around the tannery regions indicate the impact of effluent discharged from tannery units. In general, the groundwater of this study area is of Na + -Cl - type, which is due to the mixing of tannery effluent and cation exchange process. Ionic ratio indicates that the silicate weathering influences the groundwater chemistry. The permissible limit of chromium in the groundwater exceeds in over 50 % of the sampling wells. The factor analysis reveals that the dominant source for ionic contents is due to tannery effluents and cation exchange processes. To overcome this situation, it is essential to improve the performance of the effluent treatment plants so as to remove the salinity of wastewater and to plan for rainfall recharge structures for improving the groundwater recharge.

Environmental carrying capacity is a measure of competence of a lake to accommodate pollution inputs without degrading water quality. In the research reported here, we identified the factors influencing the environmental carrying capacity of Vellayani Lake or VL (a typical tropical freshwater lake), Thiruvananthapuram, Kerala State, India. R-mode factor analysis is used to identify the factors controlling the carrying capacity of the lake, whereas hierarchical cluster analysis (HCA) helped to classify the lake. The carrying capacity of the lake is low with respect to alkalinity, due to ion deficiency, and is potentially reactive to sudden changes in pH. Eutrophic condition exists in the entire lake system. Acidic factor, mineralization factor, fertilizer factor (P & K), evaporation factor and organic pollution factor are the controllers of VL water quality during the pre-monsoon period. The same factors (but not evaporation factor) and an additional runoff factor control the water quality during monsoon. In the post-monsoon, the aforesaid factors (other than runoff, alkalinity) and soil erosion factor influence the water quality. Hence, managers of the lake system need to also focus on combating acidic factor during pre- and post-monsoons and runoff during monsoon. Smaller areal extent and shallow depth of VL, reduced outflow from it, less rainfall, presence of lateritic rock and soil and absence of limestone strata in the catchment are the chief elements affecting the acidic factor of Vellayani Lake.

The water quality of the Tigris Channel at Al-Taji area were studied in both periods (August, and March, 2022). Eight samples were collected from Tigris channels to investigate water quality and parameters such as electrical conductivity (EC), total dissolved solids (TDS), Temperature (T), hydrogen number (pH), Total Hardness (T.H), as well as significant cations (Ca2+, Mg 2+, Na+, and K+ ), significant anions (CO3 2-, HCO3-, Cland SO4 2- ) and Heavy metals (Cd, Pb, Fe, Zn, Ni and Cr). The results show that the maximum value of EC is 1182 (µS/cm) in Ch3 in the dry period, while the lowest value of EC is1105 (µS/cm) in Ch1 in the wet period. The hydrochemical formula of water samples in both periods is CaCl. In this study, the dominating cation is Ca2+, followed by Na+, Mg2+, and K+, whereas the dominant anion is Cl-, followed by SO4 2-, HCO3-, and CO3- . According to Piper's illustration, all water samples that fall in class (e) are arranged together for both periods (wet and dry) "Earth alkaline water with a higher percentage of alkali and a sulfate and chloride predominance." Finally, the WQI is rated excellent for the wet Tigris channel and good water for the dry Tigris channel. [ABSTRACT FROM AUTHOR]

The confined groundwater of arid sedimentary plains has been disturbed by long‐term anthropogenic extraction, and its hydrochemical quality is required for sustainable development. The present research investigates the hydrochemical characteristics, formation, potential health threats, and quality suitability of the confined groundwater in the central North China Plain. Results show that the confined groundwater has a slightly alkaline nature in the study area, predominantly dominated by fresh‐soft Cl‐Na and HCO3‐Na types. Water chemistry is governed by water–rock interactions, including dissolution of evaporites and cation exchange. Approximately 97% of the sampled confined groundwaters exceed the prescribed standard for F−. It is mainly due to geological factors such as mineral dissolution, cation exchange, and competitive adsorption of HCO3− and may also be released from compacted soils because of groundwater extraction. Enriched F− in the confined groundwater can pose an intermediate and higher non‐carcinogenic risk to more than 90% of the population. It poses the greatest health threat to the population in the north‐eastern part of the study area, especially to infants and children. For sustainable development, the long‐term use of confined groundwater for irrigation in the area should be avoided, and attention should also be paid to the potential soil salinization and infiltration risks. In the study area, 97% of the confined groundwaters are found to be excellent or good quality for domestic purposes based on Entropy‐weighted Water Quality Index. However, the non‐carcinogenic health risk caused by high contents of F− cannot be ignored. Therefore, it is recommended that differential water supplies should be implemented according to the spatial heterogeneity of confined groundwater quality to ensure the scientific and rational use of groundwater resources. Practitioner Points: The hydrochemistry quality of confined groundwater in an arid sedimentary plain disturbed by long‐term anthropogenic extraction was investigated.The suitability of confined groundwater for multiple purposes such as irrigation and drinking were evaluated.The hydrochemical characteristics and formation mechanism of confined groundwater under the influence of multiple factors were revealed. [ABSTRACT FROM AUTHOR]

This study investigates the Batha endorheic basin in Chad, situated east of the Lake Chad basin in the arid to semi-arid Sahelian zone. This region has not yet undergone comprehensive geological and hydrogeological studies. More broadly, the transition zone between semi-arid and arid climates has been minimally explored. This research aims to evaluate the resources and dynamics of this multi-layered system using a combined geology-hydrogeology-hydrochemistry-isotopes approach. The multilayer system includes sedimentary layers (Quaternary, Pliocene, and Eocene) over a crystalline basement. A piezometric investigation of the system shows a general SE–NW groundwater, indicating an interconnection between all layers. Hydrochemical analyses identifies four main facies (calcium-bicarbonate, sodium-bicarbonate, sulphate-sodium, and mixed), primarily controlled by water–rock interaction with secondary influences from base-exchange and evaporation. Saturation indices indicate that these waters are close to equilibrium with the calcite-Mg phases, gaylussite and gypsum. Stable isotopes (oxygen-18 and deuterium) categorize groundwater into three groups: ancient water, recent and older meteoric water mixtures affected by evaporation, and mixtures more heavily impacted by evaporation. Tritium contents reveal three groups: current rainwater, modern water, and sub-modern water. These results indicate that ionic and isotopic differentiations cannot be strictly linked to specific layers, confirming the interconnected nature of the Batha system. The observed heterogeneity is mainly influenced by lithological and climatic variations. This study, though still limited, enhances significantly the understanding of the basin's functioning and supports the rational exploitation of its vital resources for the Batha area's development. Future investigations to complete the present study are highlighted. [ABSTRACT FROM AUTHOR]

The water level of Lake Hulun has changed dramatically in recent years. The interannual interaction between groundwater and lake water is an important factor affecting Lake Hulun's water level. Vertical recharge between groundwater and the lake is particularly important. Based on an analysis of differences between the hydrogeochemical and water quality characteristics of the spring water, the lake water, and the surrounding groundwater, the source and recharge mechanism of the spring water in the vertical recharge lake are determined. The results show that spring water is exposed at the bottom of Lake Hulun, and there are obvious differences between spring water and lake water in lake ice thickness, ion characteristics, and water quality characteristics. For example, the ice thickness at the spring site is only 6.8% of the average ice thickness of the lake, and there is a triangular area directly above the spring water area that is not covered by ice; the ion contents of the spring water at the lake bottom were less than 50% of those in the lake water; and the NH4+-N content of the spring water at the lake bottom was only 3.0% of the mean content of the lake water. In addition, the total nitrogen (TN), dissolved oxygen (DO), and NH4+-N contents of the spring water at the lake bottom all fall outside the range of contents of the surrounding groundwater. In general, the source of the spring water at the lake bottom is not recharged by the infiltration recharge of the phreatic aquifer but by the vertical recharge of the confined aquifer. Additionally, the Lake Hulun basin may be supplied with confined water through basalt channels while it is frozen. The vertical groundwater recharge mechanism may be that spring water at the lake bottom is first supplied by the deep, confined aquifer flowing through the fault zone to the loose-sediment phreatic aquifer under the lake, and finally interacts with the lake water through the phreatic aquifer. [ABSTRACT FROM AUTHOR]

The present study offers a quality assessment of the mineral and spring waters marketed in Algeria within the national and international legislations, examine the potential contribution of bottled waters to essential elements intake and effects on public health based on empirical, graphical tools, multivariate statistical techniques and (DRI) system. The study covered a dataset of 30 mineral and 33 spring brands. The parameters included, from bottle labels, were of physicochemical nature. All brands comply with national and WHO norms for the bottled waters, except for (Brand#63) in which NO2− exceeded the maximum permissible limit for mineral water and (Brands#4 and #21) where TH and TDS exceeded the Algerian recommended guidelines for spring water. Nearly 5% of the total brands were of bicarbonate nature belonging to mineral water, while 25% of all brands were suitable for low-sodium-diet. PCA and HCA showed that bottled waters could be classified into two distinct groups, according to degree of mineralization. The DRI-system revealed that Algerian bottled waters contributed substantially to the daily intake for Mg2+ with up to (63%), Na+ (40.36%) and Ca2+ (36%) for spring water for different ages and genders, whereas mineral water exceeded the maximum recommended daily intake for Ca2+ (128%) and Na+ (148.36%) for adults. HIGHLIGHTS An updated survey of the bottled water production units and consumption in Algeria was carried out.; A spatial distribution of the bottled water production units nationwide was studied.; Particularly, a quality assessment of the bottled mineral and spring waters marketed in Algeria was analyzed.; For the first time, an estimate of the bottled waters minerals contribution to dietary intake based on the DRI system was done.; Their effects on public health were studied.;

The over-extraction of groundwater has resulted in seawater intrusion and the southward migration of the saltwater interface, gradually deteriorating the groundwater quality in the Weibei Plain. In this research, groundwater samples were gathered from 46 monitoring wells for shallow groundwater during the years 2006, 2011, 2016, and 2021. The hydrochemical features of regional groundwater and the factors influencing the issue were subjected to statistical analysis. Additionally, the assessment of spatiotemporal variations in groundwater quality was conducted using the customized entropy-weighted water quality index (EWQI) method. The relationship between groundwater over-extraction and the southward intrusion of the saltwater interface was compared and analyzed. The results of this paper revealed that the Weibei Plain has been in a state of long-term over-extraction of groundwater from 2000 to 2021, with an average annual over-extraction of 118.49 million m3. The groundwater depression cone areas in the northern part of the study area increased from 3,247.37 to 4,581.34 km2 from 2006 to 2021, with the center of the cone experiencing a drop in groundwater level from -22 to -85 m. The saltwater interface shifted southward by 711.71 km2 from 2006 to 2021. In groundwater, the high concentrations of TH, TDS, and Cl- were primarily related to the seawater intrusion, while higher concentrations of NO3- were mainly determined by frequent agricultural production, industrial wastewater, and domestic sewage discharges. The groundwater hydrochemical types in the study area transitioned from predominantly HCO3 Ca-Mg type in 2006 to HCO3-Na type and SO4 Cl-Ca Mg type in 2021 due to seawater intrusion. The results of PCA and HCA show the effects of seawater intrusion, human activities, and rock weathering on groundwater hydrochemistry. The evaluation results based on the EWQI revealed that the average value of the samples in 2021 was 101.36, which belonged to Class IV water quality standards, representing the poorest water quality among the 4 years. The southward migration of the saltwater interface led to the deterioration of groundwater quality in the groundwater depression cone areas, which gradually worsened from 2006 to 2021. The maximum increase in EWQI value was 174.68 during the period, shifting from Class III water quality to Class V water quality. Groundwater quality remained relatively better in the western and southern regions which were less affected or unaffected by seawater intrusion. The results of the study can provide a certain reference value for the sustainable management of groundwater resources and the management of groundwater pollution and seawater intrusion in the Weifang City area in the future. [ABSTRACT FROM AUTHOR]

Copyright of Geology & Exploration is the property of Geology & Exploration Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This research examines groundwater quality in terms of its appropriateness for drinking and agricultural use, the possible human health hazards associated with arsenic exposure, the role of industries in contaminating groundwater, and their impact on the surrounding community. The drinking water assessment includes the examination of physical and chemical parameters to determine compliance with national and international standards. The study emphasizes the requirement for efficient groundwater management and monitoring to guarantee its safe and long-lasting usage for agricultural and drinking reasons. Observing the hydrogeochemical properties helps scientists to thoroughly understand groundwater pollution. Twenty-two samples were collected from the district of Faisalabad city in Punjab, Pakistan. This study aimed to investigate groundwater quality and hydrogeochemical characteristics in Faisalabad city. Groundwater samples were collected from various wells and boreholes and were analyzed using various analytical techniques to determine their physical and chemical properties. The results of the study were then used to identify potential sources of contamination and to assess the overall quality of the groundwater. In addition, the study evaluated the hydrogeochemical processes that affect the area's quality and availability of groundwater. [ABSTRACT FROM AUTHOR]

Despite their importance in carbon cycling and catchment runoff dynamics, the hydrology of temperate peat swamps in response to changing hydrometeorological conditions is largely understudied. We examined the importance of hydrogeomorphic settings in controlling hydrological connectivity and runoff in a temperate peat swamp in southern Ontario, Canada over two consecutive growing seasons with contrasting conditions (dry and wet years). We chose two different small‐scale hydrogeomorphic settings to investigate: (i) a site with strong wetland‐stream interactions (i.e., an unconfined stream channel; unconfined) and (ii) a site with limited wetland‐stream interactions (confined). During the wet year, the confined site exhibited a consistently gaining stream, maintaining lateral hydrological connectivity and yielding high runoff ratios, while during the dry year, the confined site lost water and experienced low runoff ratios during storm events. Overland flow at the unconfined site maintained a longitudinal hydrological connectivity delivering water to its sub‐catchment outflow, as reinforced by hydrochemical observations. This connectivity was maintained in the wet year but ceased in the dry year despite consistent upstream sub‐catchment water inflow due to high depression storage. Runoff ratios were reduced because of this hydrological disconnection. We highlight the importance of small‐scale hydrogeomorphic setting on peat swamp carbon storage as facilitated by the variation of within‐site hydrological connectivity and runoff, which also has important implications for downstream water quality. The unconfined site maintained a higher water table position in both years and has much greater peat carbon stocks. We suggest peat swamp channelization either naturally or through drainage decreases carbon stocks. [ABSTRACT FROM AUTHOR]

Lhasa, perched atop the Qinghai Tibet Plateau, has particular hydrochemical evolution characteristics as well as a distinct biological habitat. Rapid development has jeopardized the surface and groundwater. To maintain water safety and community health, a scientific examination of groundwater quality and human health problems is essential. A complete investigation of Lhasa's hydrochemical evolution was carried out using 65 water samples, including 14 surface water samples and 51 groundwater samples, and the quality of the surface and groundwater was assessed. Health hazards were also assessed. According to the findings, both surface water and groundwater have decreased salinity, hardness, and alkalinity. According to the Comprehensive Weighted Water Quality Index statistics, the average water quality indices for surface water and groundwater are 16.28 and 14.14, respectively, indicating good water quality. Surface and groundwater are suitable for agricultural irrigation due to their low salt absorption rates. According to the study of hydrochemical development and regulating factors, rock weathering is a phenomenon that affects both surface water and groundwater. Water is unaffected by precipitation or human actions. According to the human health risk assessment, children have a higher risk of non-carcinogenicity than adults, and the primary exposure route is daily oral ingestion. Non-carcinogenic health risk indices for nitrate consumption in children and adults are 0.220 and 0.136, respectively, indicating a lower non-carcinogenic risk of nitrate in the region's surface and groundwater, and the younger the age, the higher the non-carcinogenic health risk of nitrate intake. This study provides data support for local water resource management and optimization, as well as a reference for the chemical evolution of urban water and the evaluation of nitrate non-carcinogenic risk in global alpine regions. [ABSTRACT FROM AUTHOR]

The qualitative and quantitative assessment of groundwater is one of the important aspects for determining the suitability of potable water. Therefore, the present study has been performed to evaluate the groundwater quality for Achhnera block in the city of Taj, Agra, India, where groundwater is an important water resource. The groundwater samples, 50 in number were collected and analyzed for major ions along with some important trace element. This study has further investigated for the applicability of groundwater quality index (GWQI), and the principal component analysis (PCA) to mark out the major geochemical solutes responsible for origin and release of geochemical solutes into the groundwater. The results confirm that, majority of the collected groundwater samples were alkaline in nature. The variation of concentration of anions in collected groundwater samples were varied in the sequence as, HCO3− > Cl− > SO42− > F− while in contrast the sequence of cations in the groundwater as Na > Ca > Mg > K. The Piper diagram demonstrated the major hydro chemical facies which were found in groundwater (sodium bicarbonate or calcium chloride type). The plot of Schoellar diagram reconfirmed that the major cations were Na+ and Ca2+ ions, while in contrast; major anions were bicarbonates and chloride. The results showed water quality index mostly ranged between 105 and 185, hence, the study area fell in the category of unsuitable for drinking purpose category. The PCA showed pH, Na+, Ca2+, HCO3− and fluoride with strong loading, which pointed out geogenic source of fluoride contamination. Therefore, it was inferred that the groundwater of the contaminated areas must be treated and made potable before consumption. The outcomes of the present study will be helpful for the regulatory boards and policymaker for defining the actual impact and remediation goal. [ABSTRACT FROM AUTHOR]

Spring constitutes one of the primary water resources in some parts of the world, such as the Indian Himalayas. However, these remain imperfectly surveyed and delineated far and wide in most areas worldwide. Due to natural and anthropogenic factors, the springs are under great threat. All over the globe, springs have left as data deficit and have not relatively gained considerable attention in comparison to other systems like rivers, streams, lakes, and wetlands. This is also true for India, where most of the research is usually centered on groundwater, rivers, lakes and wetlands. This manuscript presents an overview of studies carried out on various themes of spring water systems, such as characteristics, classification schemes, and different empirical and analytical methods at international and national levels. A comprehensive overview of the literature identified the demand for an integrated approach of different empirical and analytical methods to strengthen the understanding of spring hydrology in the Himalayan region and elsewhere. Research highlights: Springwater system protection needs a forewarning of imminent contamination and thus, an integrated approach of conceptual and management-related groundwater models should be developed in India on a large scale. Empirical and analytical approaches should be used to attain an inclusive understanding of springwater hydrology and water quality. Himalayan springs should be studied considering the current updated classification schemes to obtain a comprehensive understanding of them. Monitoring of data and simulation models should be developed to establish an integrated and comprehensive understanding of Himalayan spring hydrogeology and hydrology. [ABSTRACT FROM AUTHOR]

The Ramaroshan Lake Complex (RLC) in Sudurpaschim Province, Nepal, is a Himalayan lake cluster that holds significant ecological, economic, religious, and esthetic importance. This study aimed to provide a comprehensive characterization of the hydrochemical properties of water within the RLC and assess its suitability for irrigation purposes. A total of 38 water samples were collected from seven different lakes of the complex. The physicochemical parameters and major ions were then analyzed. The water samples from the RLC were alkaline, and based on total hardness, they ranged from soft to moderately hard categories. The presence of major ions included the following: Ca2+ > Na+ > Mg2+ > K+ > Fe3+ > NH4+ and HCO3− > Cl− > SO42− > NO3− > PO43−. The alkaline earth metals (Ca2+ and Mg2+) dominated the alkali metals (Na+ and K+) and weak acids (HCO3−) dominated the strong acids (Cl− and SO42−). The dominant hydrochemical facies of the lake water was a Ca-HCO3 type indicating a calcium carbonate type of lithology. Carbonate rock weathering was the most dominant process in influencing the hydrochemistry of the water. A high ratio of (Ca2++ Mg2+)/Tz+ and a lower ratio of (Na+ + K+)/Tz+ revealed the dominance of Ca2+ and Mg2+ resulting from carbonate weathering, with little contribution from silicate weathering. Different irrigation indices revealed the suitability of the RLC water for irrigation. The insights derived from this study are pivotal in safeguarding water quality and bolstering sustainability efforts. The study also furnishes foundational data crucial to an array of stakeholders including researchers and policymakers and significantly contributes to advancing water management strategies and fostering ecosystem conservation in the Himalayan freshwater lakes, particularly in the face of the overarching challenge posed by global climate change. [ABSTRACT FROM AUTHOR]

Copyright of Hydrogeology Journal is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Study region: This study was carried out at the Chinese Loess Plateau (CLP), which is located in the middle reach of the Yellow River in the northern China. Study focus: Understanding groundwater hydrochemistry and its controlling factors in regions like CLP with thick unsaturated zones is challenging due to limited accessibility. The primary objective of this study was to investigate groundwater hydrochemistry, sources, and controls, and assess groundwater suitability for drinking and irrigation purposes across 14 major catchments in CLP. New hydrological insights for the region: Our results showed that the composition of groundwater dissolved solutes is primarily influenced by weathering rock, particularly silicate rock. However, human activities, especially in agriculture and urban areas, also have a notable impact on groundwater solutes. The presence of elevated nitrate in groundwater in various regions underscores the urgency of addressing long-term nitrogen pollution. Environmental changes such as climate change, erosion rates, and land-use patterns are key factors shaping groundwater quality. As air temperature decreases and erosion intensifies, along with more intensive land use, ion concentrations in groundwater tend to rise. Note that, approximately 91% of groundwater in CLP is suitable for direct drinking, but ensuring proper drainage is crucial to prevent sodium damage during irrigation. These findings enhance our understanding of the factors influencing groundwater solutes and are essential for effectively managing groundwater quality in CLP.

The Ramaroshan Lake Complex (RLC) in Sudurpaschim Province, Nepal, is a Himalayan lake cluster that holds significant ecological, economic, religious, and esthetic importance. This study aimed to provide a comprehensive characterization of the hydrochemical properties of water within the RLC and assess its suitability for irrigation purposes. A total of 38 water samples were collected from seven different lakes of the complex. The physicochemical parameters and major ions were then analyzed. The water samples from the RLC were alkaline, and based on total hardness, they ranged from soft to moderately hard categories. The presence of major ions included the following: Ca2+ > Na+ > Mg2+ > K+ > Fe3+ > NH4+ and HCO3− > Cl− > SO42− > NO3− > PO43−. The alkaline earth metals (Ca2+ and Mg2+) dominated the alkali metals (Na+ and K+) and weak acids (HCO3−) dominated the strong acids (Cl− and SO42−). The dominant hydrochemical facies of the lake water was a Ca-HCO3 type indicating a calcium carbonate type of lithology. Carbonate rock weathering was the most dominant process in influencing the hydrochemistry of the water. A high ratio of (Ca2++ Mg2+)/Tz+ and a lower ratio of (Na+ + K+)/Tz+ revealed the dominance of Ca2+ and Mg2+ resulting from carbonate weathering, with little contribution from silicate weathering. Different irrigation indices revealed the suitability of the RLC water for irrigation. The insights derived from this study are pivotal in safeguarding water quality and bolstering sustainability efforts. The study also furnishes foundational data crucial to an array of stakeholders including researchers and policymakers and significantly contributes to advancing water management strategies and fostering ecosystem conservation in the Himalayan freshwater lakes, particularly in the face of the overarching challenge posed by global climate change.

The Hutuo River Drinking Water Source Area is an important water source of Shijiazhuang (North China Plain). Knowing the characteristics of groundwater chemistry/quality is essential for the protection and management of water resources. However, there are few studies focused on the groundwater chemistry evolution over the drinking water area. In this study, total of 160 groundwater samples were collected in November 2021, and the spatial distribution of groundwater chemistry and related controlling factors were analyzed using hydrological and multivariate analysis. The entropy-weighted water quality index (EWQI) was introduced to assess the groundwater quality. The results show that the hydrogeochemical types of groundwater are Ca-HCO3 (78.1%), mixed Ca-Mg-Cl (20%), and Ca-Cl (1.9%) in the area. Graphical and binary diagrams indicate that groundwater hydrochemistry is mainly controlled by water–rock interaction (i.e., rock weathering, mineral dissolution, and ion exchange). Five principal components separated from the principal component analysis represent the rock–water interaction and agricultural return, redox environment, geogenic sources, the utilization of agricultural fertilizer, the weathering of aluminum silicates, and dissolution of carbonates, respectively. More than 70% of the samples are not recommended for irrigation due to the presence of high salt content in groundwater. EWQI assessment demonstrates that the quality of the groundwater is good. The outcomes of this study are significant for understanding the geochemical status of the groundwater in the Hutuo River Drinking Water Source Area, and helping policymakers to protect and manage the groundwater. [ABSTRACT FROM AUTHOR]

The present effort is expected to consider the groundwater quality of the Erbil Central Basin. In this study, we compared the physiochemical properties and distribution of major cations and anions in groundwater to evaluate the quality assessment as a special usage (drinking and irrigation) and identify the sources and types of water quality variation and pollution. The mean richness of major cations are Ca2+ > Mg2+ > Na+ > K+, whereas the major anions are HCO3 - > SO4²- > NO3 - > Cl-. The quality of water was evaluated using SAR, sodium (%), PI, TH, MH, PS, and WQI. When the chemical and physical characteristics were compared to Iraqi and public health standards (IQS) for drinking water, it was discovered that the majority of the wells' groundwater during both periods was within the acceptable range, and suitable for all human drinking and domestic purposes except for three wells exceed the maximum permissible limit of NO3-, which are Newroz, Rizgari, and Birayaty, while HCO3- is showed a maximum in Newroz, and in Rizgari well the total hardness (TH) doesn't lie within recommended standards. The Ca and Mg- Bicarbonate type was the predominant form for the groundwater classified for both seasons, with only one well (Zanko) being Ca- Chloride type for the dry season. The majority of ionic species originated from alkaline earth metals that originate from interactions between weak acidic anions in groundwater and soil or rock. All samples were suitable for drinking water according to the WQI, only the Zanko well had poor water during the dry season. [ABSTRACT FROM AUTHOR]

The present study analyses water quality parameters in the Kuwano River, Basti district, using correlation and regression analysis to establish relationships between variables and provide a comprehensive understanding of the factors influencing water quality. Kuwano is the main river that flows through Basti city. The water samples were collected at three locations. The values of different physicochemical parameters of the river water sample were found to be dependent on the hydrology of the area. The pH was strongly associated with TDS (r = 0.885), DO (r = 0.744), COD (r = 0.969), TH (r = 0.806), and Mg (r = 0.944). The biological oxygen demand (BOD) (-0.345), nitrate (-0.235), and calcium (-0.128) exhibited an inverse correlation with total dissolved solids (TDS), whereas nitrate and calcium had a positive correlation with all other physicochemical parameters. The mean TDS value of the river water sample (81.2) was within the permissible limit for drinking water. The total coliform counts established a negative correlation with most of the parameters studied, e.g., dissolved oxygen (-0.628), BOD (-0.983), chemical oxygen demand (-0.194), total hardness (-0.549), nitrate (-0.955), Ca (-0.918) and Mg (-0.279). The study's findings may provide practical information for decision making in river pollution management. [ABSTRACT FROM AUTHOR]

The over-extraction of groundwater has resulted in seawater intrusion and the southward migration of the saltwater interface, gradually deteriorating the groundwater quality in the Weibei Plain. In this research, groundwater samples were gathered from 46 monitoring wells for shallow groundwater during the years 2006, 2011, 2016, and 2021. The hydrochemical features of regional groundwater and the factors influencing the issue were subjected to statistical analysis. Additionally, the assessment of spatiotemporal variations in groundwater quality was conducted using the customized entropy-weighted water quality index (EWQI) method. The relationship between groundwater over-extraction and the southward intrusion of the saltwater interface was compared and analyzed. The results of this paper revealed that the Weibei Plain has been in a state of long-term over-extraction of groundwater from 2000 to 2021, with an average annual over-extraction of 118.49 million m3. The groundwater depression cone areas in the northern part of the study area increased from 3,247.37 to 4,581.34 km2 from 2006 to 2021, with the center of the cone experiencing a drop in groundwater level from −22 to −85 m. The saltwater interface shifted southward by 711.71 km2 from 2006 to 2021. In groundwater, the high concentrations of TH, TDS, and Cl− were primarily related to the seawater intrusion, while higher concentrations of NO3− were mainly determined by frequent agricultural production, industrial wastewater, and domestic sewage discharges. The groundwater hydrochemical types in the study area transitioned from predominantly HCO3·Ca-Mg type in 2006 to HCO3-Na type and SO4·Cl-Ca·Mg type in 2021 due to seawater intrusion. The results of PCA and HCA show the effects of seawater intrusion, human activities, and rock weathering on groundwater hydrochemistry. The evaluation results based on the EWQI revealed that the average value of the samples in 2021 was 101.36, which belonged to Class IV water quality standards, representing the poorest water quality among the 4 years. The southward migration of the saltwater interface led to the deterioration of groundwater quality in the groundwater depression cone areas, which gradually worsened from 2006 to 2021. The maximum increase in EWQI value was 174.68 during the period, shifting from Class III water quality to Class V water quality. Groundwater quality remained relatively better in the western and southern regions which were less affected or unaffected by seawater intrusion. The results of the study can provide a certain reference value for the sustainable management of groundwater resources and the management of groundwater pollution and seawater intrusion in the Weifang City area in the future.

This study investigates the Batha endorheic basin in Chad, situated east of the Lake Chad basin in the arid to semi-arid Sahelian zone. This region has not yet undergone comprehensive geological and hydrogeological studies. More broadly, the transition zone between semi-arid and arid climates has been minimally explored. This research aims to evaluate the resources and dynamics of this multi-layered system using a combined geology-hydrogeology-hydrochemistry-isotopes approach. The multilayer system includes sedimentary layers (Quaternary, Pliocene, and Eocene) over a crystalline basement. A piezometric investigation of the system shows a general SE–NW groundwater, indicating an interconnection between all layers. Hydrochemical analyses identifies four main facies (calcium-bicarbonate, sodium-bicarbonate, sulphate-sodium, and mixed), primarily controlled by water–rock interaction with secondary influences from base-exchange and evaporation. Saturation indices indicate that these waters are close to equilibrium with the calcite-Mg phases, gaylussite and gypsum. Stable isotopes (oxygen-18 and deuterium) categorize groundwater into three groups: ancient water, recent and older meteoric water mixtures affected by evaporation, and mixtures more heavily impacted by evaporation. Tritium contents reveal three groups: current rainwater, modern water, and sub-modern water. These results indicate that ionic and isotopic differentiations cannot be strictly linked to specific layers, confirming the interconnected nature of the Batha system. The observed heterogeneity is mainly influenced by lithological and climatic variations. This study, though still limited, enhances significantly the understanding of the basin’s functioning and supports the rational exploitation of its vital resources for the Batha area’s development. Future investigations to complete the present study are highlighted.

In Algeria, groundwater frequently serves as a main source of drinking water supply. Given the country's geographical characteristics and water resource availability, many municipalities rely on groundwater to meet their drinking water needs. In this study, the quality of groundwater for drinking purposes in the northern region of the Middle Sébaou was assessed by obtaining hydrochemical data from ten groundwater samples in 2019. The study aimed to analyze and evaluate the hydrochemical composition of the groundwater using multivariate analysis and the water quality index (WQI) to determine its suitability for human consumption. Statistics showed that most of the groundwater analysis parameters are within acceptable limits except calcium (Ca2+) and bicarbonates (HCO3-) which exceed the potability standards set by the guidelines of the World Health Organization (WHO) for drinking water. Piper diagram demonstrates the existence of two hydrochemical facies: bicarbonate calcium and magnesium, and chloride as well as sulfate calcium and magnesium. According to the WQI values obtained in this study, ranging from 53.32 to 71.18, all of the groundwater samples exhibit good water quality based on the classification of the WQI method. On the basis of these results, the groundwater of the northern region of the Middle Sébaou is suitable for drinking purposes. [ABSTRACT FROM AUTHOR]

Due to an increasing reduction of hydrological resources across Mexico and their growing contamination from global warming and anthropogenic activities, this study evaluated water from the perennial Lake Coatetelco (Ca–Mg–HCO3) in tropical central-southern Mexico and groundwater (Ca–Mg–HCO3 and Na–HCO3–Cl) from the surrounding wells for drinking as well as irrigation qualities. Comparison with the WHO guidelines and the estimated water quality indices (DWQI and IWQI) grouped almost all the samples collected after the warm season rainfall in excellent and good categories (DWQI < 100) for drinking, even though fluoride remained > 1.5 mg/L in 50% samples. Except for one groundwater sample, all showed > 25% permeability (classes I and II) in Donnen classification indicating their suitability for irrigation. USSL and Wilcox classifications, however, catalogued some in the high-salinity hazard group and some as doubtful for irrigating regular plants. Samples from about 53% wells were also in high and severe restriction categories of IWQI for the irrigation. Total Hazard Quotient Index (THQI) for estimating the non-carcinogenic risk (HQfluoride > 1) showed that at least one lake water sample and 53% of groundwater might expose the adult and child population to dental and skeletal fluorosis. This water quality assessment data posterior to the rainfall season could be useful as a baseline for both the short- and long-term monitoring in attention to the United Nation's Sustainable Development Goal 6. [ABSTRACT FROM AUTHOR]

Along coasts, biologically diverse terrestrial wetlands and marine ecosystems maintain complex hydrological connections that influence groundwater quality. The coastline of Florida's panhandle is home to globally rare coastal dune lakes that are hydrologically influenced by unique wet prairies within their watersheds. Little is known regarding how changes in ecosystem structure and composition of wet prairies influences groundwater chemistry within these coastal dune lake watersheds. To identify how physical and biological characteristics of terrestrial wetlands influence water chemistry, we analyzed water quality parameters along an upland to wetland gradient of shrub-encroached and fire-maintained wetlands within four of Florida's coastal dune lake watersheds between 2018 and 2021. Shrub-encroached wetlands had significantly higher (p ≤ 0.01) specific conductivity, salinity, acidity, and ion concentrations (Cl−, SO42−, K+, Na+, and Mg2+) than fire-maintained wetlands. Ions in groundwater were similar across the upland to wetland gradient with exception of chloride which was significantly lower (p ≤ 0.01) at upper slope positions where encroaching shrubs were less dense. The sulfate in groundwater was twice that of streams and salinity was most concentrated at the bottom slope positions. As results show that shrub encroachment has a measurable relationship with water chemistry, restoration of herbaceous wetlands through shrub removal may improve water quality and minimize future impacts to Florida's coastal dune lakes. [ABSTRACT FROM AUTHOR]

Water quality plays an important role for every sustainable social and economic system, as well as for maintaining human health. This study, carried out during 2022–2023, has as its main objective the physical–chemical and microbiological analysis of some underground water resources (two boreholes and a spring) with a natural mineral load from three areas in Bihor County (Romania), and the impact of their consumption on people's health. Therefore, six microbiological parameters and 17 physical–chemical indicators in three localities (Tămășeu, Sîntimreu, Pădurea Neagră) were analyzed. The results of the microbiological analysis indicate a type of water that respects the limits imposed by the legislation on natural mineral waters and potability. The physical–chemical indicators show that the hydrochemical type of the studied waters is predominantly bicarbonate, in association with calcium, magnesium, and sodium cations. The residents' perception on water quality and the effect on people's health was assessed through a questionnaire (23 items) addressed to the population of the three villages and neighboring localities. The results showed that the mineral waters from Sîntimreu and Pădurea Neagră are used frequently. Many respondents consider the local mineral waters as without quality-related problems and with beneficial effects regarding acute or chronic gastrointestinal conditions, such as gastritis, gastric ulcers, flatulence, or liver diseases. [ABSTRACT FROM AUTHOR]

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Identification of geochemical factors controlling the formation of fluoride and quantifying exposure risks associated with fluoride in groundwater is important for drinking water resource protection and public health. In the present study, 129 groundwater samples [89 from a shallow aquifer (SG) and 40 from a deep aquifer (DG)] were collected from a drinking water resource in the North Anhui Plain in eastern China. Hydrogeochemical methods, mineral saturation indices, and a human health risk assessment model were used to determine the formation mechanism and noncarcinogenic risks of fluoride in groundwater. The results indicate that fluoride concentrations in 10.1% and 2.5% of the SG and DG samples, respectively, exceeded the Chinese groundwater quality standard. Concentrations of fluoride were higher in Na–HCO3 and Mg–HCO3 type water than in Ca–HCO3 type water. Ca2+/Na+ versus HCO3−/Na+ and Mg2+/Na+ diagrams suggest that weathering of silicate minerals is a key factor controlling groundwater chemistry and fluoride concentrations. Relationships between F− and F−/Cl−, pH and Ca2+ indicate that geologic sources are an important source of groundwater fluoride and that direct cation exchange and competitive adsorption in alkaline environments favor F− enrichment. A saturation index analysis demonstrated that calcite and dolomite were saturated, while fluorite and gypsum could be further dissolved. Noncarcinogenic risks to adults associated with fluoride in groundwater were low. However, 21.3% and 35% of the SG and DG samples, respectively, presented unacceptable noncarcinogenic risks for children. High-risk areas were identified in the central, northern and southern portions of the study area. Our findings suggest that groundwater quality management and control measures should be implemented to protect the health of the local population, particularly children, in high-risk areas. [ABSTRACT FROM AUTHOR]

Explore the hydrochemical characteristics of surface water (SW) and groundwater (GW) under coal mining activities and controlling factors is essential to ensure water security. This research concentrates on the Changhe River Basin (CRB). Water samples were collected from 27 sites within the CRB in May, July and December 2022. A qualitative analysis of hydrochemical characteristics and major ion sources was conducted based on Piper plots, Gibbs plots, Pearson correlation analysis and ion ratio methods. The PCA ~ RSR model was used to assess the current status of SW and GW quality in the CRB. We found that the hydrochemical type of SW and GW is HCO3–Ca, with HCO3− accounting for 62.2% ~ 87.9% of the total anions and Ca2+ accounting for 27.4% ~ 31.3% of the total cations. Rock weathering is the main factor affecting the hydrochemical of CRB. SW is affected by the weathering and dissolution of both silicate and carbonate rocks, while GW is mainly affected by the weathering and dissolution of silicate. The cation exchange also has influence on GW. The cations in the water are mainly derived from rock weathering dissolution and exchange reactions, while SO42− in anions is mainly imported from outside. The results of the water quality assessment showed that water quality in the midstream of the study area is poor and coal mining has seriously affected water safety issues. The study reveals the impact of coal mining on hydrochemical. It provides a scientific basis for the protection and management of water resources under coal mining activities in arid and semi-arid regions. [ABSTRACT FROM AUTHOR]

To identify the mechanism of geothermal water in Xiaoyangkou Geothermal Field, the earliest medium-temperature, high-yield geothermal resource found in Subei Basin, based on the water quality indicators of four geothermal water and one groundwater samples, hydrogeochemical and isotopic methods were used to analysis the hydrochemical characteristics, recharge sources and circulation depth of geothermal water, and to determine the reservoir temperature. Results show that the temperature of the thermal reservoir of the Neogene Yancheng Formation is about 39.5–41.64 °C. The geothermal waters are HCO3 type with TDS of 616–638 mg/L. The temperature of the Paleogene Funing Formation and Devonian–Silurian sandstone reservoir is about 95.45–110.78 °C. The geothermal waters are SO4 type with TDS of 1446–1812 mg/L. The concentrations of trace elements F, Sr and Li increased rapidly with the increase of temperature. The isotopic compositions of δ18O and δD indicates that the geothermal water is mainly recharged by atmospheric precipitation from the elevation of 145.5–524.5 m. The atmospheric precipitation infiltration is heated by the heat flow in the deep part and transported upward along the water-conducting structure through deep circulation (3.37 km) to the karst fissure at the top of the underlying strata of Yancheng Formation, forming a convective geothermal system. The upper Yancheng formation is an associated-conduction geothermal system. The research results provide reference and basis for the rational development and utilization of geothermal resources in the region. [ABSTRACT FROM AUTHOR]

Salah Al-Din Provence is an active agriculture and population region. One of its primary water sources is groundwater, which suffers from a lack of information regarding water quality and hydrochemistry. In order to study those missing variables, 27 samples from wells of shallow tubes were collected for analyzing the relevant physicochemical indices that help to produce the Schoeller index, Piper diagram, and Gibbs plot. Piper diagram revealed a hydrochemistry behavior of different values along with the groundwater samples. The chemistry of wells was controlled primarily by the evaporation process according to the Gibbs plot. The values of the Schoeller index of the studied samples stated that 59% of them have disequilibrium in Chloro-Alkaline due to their negative obtained values while the rest of them produced positive estimates, which indicates an exchange reaction of cation–anion basic domination. It was concluded that carbonate and silicate weathering, as well as evaporation, controlled the region' s hydrochemistry. Using Water Quality Index, groundwater was evaluated for use as drinking water. While using Sodium Adsorption Ratio, Sodium percentage, Residual Sodium Carbonate, Magnesium Hazard, and US salinity diagram were all used for estimating the same water' s suitability for irrigation. All of those indicators, as well as the Gibbs ratio, show that all 27 samples were unsuitable for both studied usage. In addition, those results indicate that evaporation is a major problem for groundwater in this area. Finally, using cluster analysis it was concluded that there are two types of similarities that indicate different levels of pollution in groundwater. [ABSTRACT FROM AUTHOR]

Copyright of Tecnología y Ciencias del Agua is the property of Instituto Mexicano de Tecnologia del Agua (IMTA) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Gypsum-enriched aquifers (GEA) and intensive agriculture regions (IAR) in semi-arid regions are responsible for very high amounts of sulfate and nitrate in many groundwater systems of the world, respectively. However, in such regions, the problem of nitrate pollution and its associated health risk has been increasing and emerging as a global issue. However, along with nitrate, sulfate contamination and its potential health risks are often neglected worldwide in these regions. Therefore, considering sulfate along with nitrate as a significant threat to water quality in such regions, this study aimed to characterize hydrochemistry, factors controlling groundwater quality, and assessment of risk to human health. To accomplish this objective, 116 groundwater samples were collected over pre-monsoon (PRM) and post-monsoon (POM) (2019) seasons in Bemetara district. As per Bureau of Indian standards (BIS) for drinking, SO42− (28 and 19%) and NO3− (7 and 35%) exceeded the permissible limits in PRM and POM seasons, respectively; thereby, groundwater was not suitable for drinking. SO42− and NO3− pollution sources were identified and mainly attributed to gypsum dissolution and agricultural activities as well as domestic sewage discharge, respectively. In addition, SO42−and NO3− risk assessment results show that total 20% to 46% of all samples surpassed the permissible limit (HQ = 1) of risk to children and adults, over both seasons. To ensure drinking water security in this region, sustainable management of agricultural activities and treatment should be done to reduce the potential health risks due to SO42− and NO3−. [ABSTRACT FROM AUTHOR]

The present paper assesses the hydrochemistry of groundwater in AL JALLAM desert and its suitability for human consumption and irrigation. Nine groundwater samples were taken, and they were analyzed for major ions to determine the Piper diagram and Gibbs plot. The results showed that the evaporation process is the primary control of the water quality in the study area. Water Quality Index (WQI) method was utilized to assess the suitability of water for human consumption, whereas different geochemical parameters were used to evaluate the irrigation suitability. Generally, the groundwater in the study area is not suitable for drinking and irrigation. Based on cluster analysis (CA), it was found that two levels of pollution levels in the AL JALLAM desert. [ABSTRACT FROM AUTHOR]