Explore the vast range of titles available.

Groundwater, a predominant reservoir of freshwater, plays a critical role in providing a sustainable potable water and water for agricultural and industry uses in the In Salah desert region of Algeria. This research collected 82 underground water samples from Albian aquifers to assess water quality and identify hydrogeochemical processes influencing mineralization. To achieve this objective, various methods were employed to evaluate water quality based on its intended uses. The drinking water quality index utilized revealed the water potability status, while the indicators of irrigation potability were employed to evaluate its quality for agricultural purposes. Additionally, an assessment of groundwater susceptibility to corrosion and scaling in an industrial context was conducted using several indices, e.g., Langelier index, Larson-Skold index, Ryznar index, chloride-sulfate mass ratio, Puckorius index, aggressiveness index, and the Revelle index. The findings of this study revealed that the groundwater quality for consumption fell into four categories: good (2.44%), fair (29.27%), poor (65.85%), and non-potable (2.44%). Concerning agricultural irrigation, the indexical results indicated that 15.85% of the waters exhibited adequate quality, while 84.15% were questionable for irrigation. Calculations based on various corrosion and scaling evaluation indices showed that most wells were prone to corrosion, with a tendency for calcium bicarbonate deposit formation. Furthermore, the hydrochemical study identified three water types: Na–Cl (53.66%), Ca–Mg–Cl (37.80%), and Ca–Cl (8.54%) waters. Analyses of correlation matrices, R-type clustering, factor loadings, Gibbs diagrams, scatterplots, and chloro-alkaline indices highlighted that the chemistry of the Albian groundwater is fundamentally impacted by a number of processes such as silicate weathering, evaporite dissolution, ionic exchange, and anthropogenic inputs, that played impactful role in the aquifer's water chemistry.

Groundwater contamination by the adjacent seawater has been a global problem. To address the process and evolution of salinity in groundwater, different procedures such as major ion ratios, standard plots, geophysical techniques, isotopic techniques, and modelling methods were adopted. It is difficult to distinguish the groundwaters’ with salinity, similar or greater than the seawater by adopting major ions. Saline to hypersaline conditions are reported in coastal groundwater of the arid regions. In order to address the sources of salinity, evolution and geochemical nature, groundwater samples were collected near the shore along with adjacent seawater. The ion-ratio and the Piper diagram did not show a clear demarcation between groundwater and seawater, but the fact that seawater values were within a narrow range than the groundwater. Whereas the Cl/Br and Br/Si ratios, thermodynamic stability plots of K-Silica system, Plagioclase stability and carbonate system with respect to logpCO2 reflected geochemical variation between the seawater and groundwater samples. Since the silica values of seawater samples were lesser, they proved to be a significant tracer to characterize the non-contaminated groundwater samples. The seawater–groundwater interaction was inferred from the study and probable locations of SGD were identified. The evolution mechanism of the brine composition with the present scenario was studied considering the saturation states of halite, silicates, carbonate and sulfate minerals. It was identified that the evolutionary pathway of brine from groundwater composition is governed by the Ca ion, which is a common ion for most of the carbonate and sulfate minerals. The groundwater chemistry indicates the Cl-SO4 brine evolution pathway leading to the formation of Mg-SO4 brine. Thus, the study proves that ratios of Cl/Br, Br/Si, thermodynamic stability plots with respect to silicate minerals and logpCO2 along with saturation states of minerals can serve as significant tool to characterize the hypersaline groundwater.

Groundwater sampling in challenging environments often leads to compromises in following best practices to obtain representative samples from aquifers. This includes collecting samples from existing production or domestic wells instead of using properly constructed monitoring wells or using a bailer instead of a submersible pump for sampling. To address unusual patterns and trends in groundwater chemistry data collected in Niamey, Niger from 2012–2021, a state-of-the-art monthly sampling routine was established for eight wells tapping the basement aquifer. This was based on the hypothesis that the observed changes in groundwater composition were mainly due to differences in sampling technique, and the aim of the study was to gain insights into possible seasonal variations in water composition, to examine if the previously observed trends could be validated and to provide baseline data for future studies. The results indicate that in most cases the long well response zones in the stratified aquifer system led to the collection of water from different strata/aquifers or of strongly mixed samples. Therefore, any sample from those wells is only of limited value for the interpretation of hydrogeological processes. To obtain sound data for the development of groundwater management strategies, the monitoring has to be shifted from existing production wells to properly constructed monitoring wells. In the complex hydrogeological setting of Niamey, with hydraulically interacting aquifers and occurrences of density layering, it is fundamental to ensure that a monitoring well taps one specific depth of one target aquifer and that well-volume purging is applied properly.

This study integrates multivariate statistical analysis and hydrogeochemical modeling to investigate the processes controlling the groundwater composition of a shallow aquifer where increased pumping rates and anthropogenic impacts were prevalent. Eighteen groundwater samples were collected and analyzed for major elements and selected heavy metals. The data were classified on the basis of multivariate statistical analysis into three clusters: C1 (Na-Cl facies), C2 (Ca-SO 4 facies), and C3 (Ca-HCO 3 facies). The application of factor analysis gave four factors affecting the groundwater chemistry, namely the salinization factor, anthropogenic/secondary enrichment factor, the secondary and the micro-nutrient fertilizers, and the aluminum fertilizer factor. The hydrogeochemical study of the groundwater revealed that the processes controlling the groundwater chemistry in the study area are mainly affected by the groundwater occurrence either to the east or to the west of Bahr Youssef Canal. Generally, the dominant hydrogeochemical processes affecting the groundwater are silicate weathering, ion exchange, irrigation return flow, gypsum applications in soil, and evaporation. The groundwater quality evaluation shows that water quality varies from fair to excellent for drinking purposes, where the best water is located in the northern and central parts of the study area. The suitability of groundwater for irrigation was evaluated using several indices indicating that groundwater is suitable for irrigation in the northwest and western parts of the study area. As some groundwater samples lie in high salinity classes on the US Salinity diagram, it is recommended to use this water for plants with good salt tolerance under good drainage conditions. The integration between the statistical and geochemical tools helps reveal the dominant processes through data reduction and classification.

Expansion of the hydrologically connected area during rainfall events causes previously disconnected areas to contribute to streamflow. If these newly contributing areas have a different hydrochemical composition compared to the previously connected contributing areas, this may cause a change in stream water chemistry that cannot be explained by simple mixing of rainfall and baseflow. Changes in stormflow composition are, therefore, sometimes used to identify when transiently connected areas (or water sources) contribute to stormflow. We identified the dominant sources of streamflow for a steep 20 ha pre-Alpine headwater catchment in Switzerland and investigated the temporal changes in connectivity for four rainfall events based on stream water concentrations and groundwater level data. First, we compared the isotopic and chemical composition of stormflow at the catchment outlet to the composition of rainfall, groundwater and soil water. Three-component end-member mixing analyses indicated that groundwater dominated stormflow during all events, and that soil water fractions were minimal for three of the four events. However, the large variability in soil and groundwater composition compared to the temporal changes in stormflow composition inhibited the determination of the contributions from the different groundwater sources. Second, we estimated the concentrations of different solutes in stormflow based on the mixing fractions derived from two-component hydrograph separation using a conservative tracer (δ2H) and the measured concentrations of the solutes in baseflow and rainfall. The estimated concentrations differed from the measured stormflow concentrations for many solutes and samples. The deviations increased gradually with increasing streamflow for some solutes (e.g. iron and copper), suggesting increased contributions from riparian and hillslope groundwater with higher concentrations of these solutes and thus increased hydrological connectivity. The findings of this study show that solute concentrations partly reflect the gradual changes in hydrologic connectivity, and that it is important to quantify the variability in the composition of different source areas.

Textile dyeing and weaving of traditional longyi garments have traditionally occurred in the Amarapura township of Mandalay, Myanmar, since 1822, transitioning from natural to chemical dyes in the early 1900s. With no current wastewater treatment facilities in Mandalay, dye effluents mix with other wastewaters in unlined canals dug near people’s homes and discharge into the local canals and groundwater. Because locals rely heavily on dug and tube wells for drinking, bathing, and cooking, this industry poses a major health hazard to the people in this region. The objective of this study was to identify the previously unknown composition of the textile dyes, as well as identify and quantify the concentrations of major ions and heavy metals found in dye effluents, and determine their impact on the local groundwater resources. Powdered dye samples from each stage of the dyeing process were characterized by the combination of heavy metals used to create these color dyes. Groundwater and surface water were also sampled. Results of analysis of the dye and water samples indicated that most of the heavy metals discharge into the groundwater environment. Textile dyeing is a major source of pollution and a health hazard to the residents of Amarapura township; however, the locals are not readily connecting dye practices to the issues with their drinking water. This study provides information on groundwater composition near dyeing industries in Amarapura township that may help inform further monitoring strategies and communicate the health risks of exposure to heavy metals for local people.

Shallow groundwater resources, especially in hard rock environment, constitute an important part of urban water supply in developing countries, appropriate to the low level of economic development. However, increasing urban population and dependence on shallow groundwater systems make it imperative to evaluate the availability and the contamination of these resources, and define new strategies of water exploitation taking into accounts these findings and constrains. This study has been carried out on the shallow groundwater of Yaounde, Central Africa. Based on head slug-in tests, chemical and isotope analyses, we demonstrate the importance of geomorphological settings that constrain hydrogeology, urban occupation and therefore, water exploitation and contamination. Slug test results show spatial variability of well recovery rates with higher values recorded in the valleys compare to the hills, presenting saturated hydraulic conductivity of 10–6–10–8 m/s. Groundwater evolves from recharge zone as Ca–HCO3 in the hillside lateritic system to discharge zone in the slope/valley colluvium/alluvium system as NaK–NO3. The groundwater composition dominated by silicates/water interaction in the hillside lateritic system, and anthropogenic processes in the slopes and valleys. δ15N and δ18O of nitrates indicates that nitrate pollution of groundwater is mainly from sewage and human waste. Shallow groundwater resources in the hillside/new urban districts and to a lesser extent slopes should therefore be protected and prioritised for usability and sustainability. The proposed conceptual scheme for Yaounde can then be used as a guide in the development, exploitation and management of local wells in hard rocks system of Africa.

The main aim of this research is to assess the consequences of natural and anthropogenic processes on the groundwater quality of 65 deep aquifers of Nagpur city, Maharashtra Province, India, using a unified multivariate statistical approach. The dominant groundwater type recognized is Ca–HCO 3 (recharge waters) in 43.1 and 38.5% of groundwater samples of pre- and post-monsoon seasons, followed by mixed water types. The seasonal distribution of physicochemical parameters shows increase in the concentration of EC, TDS, TH, Mg 2+ , SO 4 2− , and NO 3 − signifying the high mineralization and anthropogenic loading from pre- and post-monsoon season respectively. The entropy-weight water quality index categorizes the 84.6% and 75.4% of total samples from pre- and post-monsoon seasons into moderate quality. The multiple linear regression and PCA analysis reveal the masking of rock weathering mechanism by anthropogenic activities. The % of PCA Variance varies from 79 to 83.7% from pre- to post-monsoon season. The high contributions of EC (0.76, 0.72), TDS (0.79, 0.73), TH (0.97, 0.962), Ca 2+ (0.84, 0.78), Mg 2+ (0.79, 0.83), Cl − (0.73, 0.75), and NO 3 − (0.78, 0.68) in PC1 components expose high salinity and hardness in urban groundwater that signifies the consequences of urbanization on the groundwater regime. About 55.4 and 70.8% of children population as compared to the adult female (53.8%, 69.2%) and male (32.3%, 46.1%) population in PRM and POM respectively were at high non-carcinogenic health threat of NO 3 − -enriched groundwater. The study is beneficial for understanding the variation in groundwater composition due to unplanned urbanization and is very useful for protecting groundwater resources in urban areas.

The present study aimed to identify the formation factors of the current hydrogeochemical character of the Middle-Jurassic aquifer groundwaters (beds YU 2-4) in the Lyaminsky petroleum district of West Siberia in Russia. We hypothesized that the scales of the impact of post-sedimentation processes at the current stage have largely predetermined the character of the Middle-Jurassic aquifer system. To check if the hypothesis is valid, two research problems have been addressed using the lithogenesis theory of the transformation of the groundwater composition during the geologic evolution: we have evaluated factors that governed the genetic type and composition of initial waters (lithologic, paleogeographic), and factors that control subsequent changes in the chemical composition of groundwaters (geotemperatures, neotectonics effect, etc.). To solve the first problem, the formation conditions of groundwaters under study in the continental setting were investigated. To settle the second problem, we obtained the coefficients of correlation between the Middle-Jurassic aquifer groundwater salinity and the current temperature and paleotemperature of the Tyumenian suite, and between the porosity coefficient and the basement depth. We have concluded that the current hydrogeochemical character of the Middle-Jurassic aquifer system is the resultant of the consecutive effects of the whole set of factors.

Wadi Nisah which lies to the south of Riyadh city is an important source of groundwater supply and agricultural production in the central region of Saudi Arabia. Twenty-nine groundwater samples were collected from wells tapping the shallow alluvial aquifer as well as the Mesozoic Manjur and Dhruma aquifer in western Wadi Nisah. The interpretation of the results of the major ion analysis reveals that geogenic factors mainly rock–water interaction and mineral dissolution control the groundwater chemistry. The samples are characterized by high TDS and EC values. Saturation indices of the groundwater show that minerals dissolution is the primary factor affecting the groundwater composition Piper plot reveals groundwater mixing as Ca + Mg − Cl + SO4 facies, mixed Ca + Mg − Cl + SO4 facies and Na + K + Cl + SO4 facies is present in the study area. Gypsum and dolomite weathering coupled with reverse-ion exchange are responsible for the dominance of alkaline earth elements over alkali elements. Principal component analysis helped in the extraction of three principal components accounting for approximately 78% of the total data variability. The extracted components point mainly towards geogenic influences. However, the third principal component shows the influence of anthropogenic pollution, mainly nitrate pollution from agricultural activity in the area.