Groundwater Geochemistry Research Articles

Geochemistry of Groundwater in the Semi-Arid Crystalline Terrain of Sri Lanka and Its Health Implications among Agricultural Communities

Chronic kidney disease with uncertain etiology (CKDu) is an emerging health problem in Sri Lanka, particularly among the dry-zone farming communities that use groundwater for drinking. We investigated the quality of groundwater in an area where both high- and low-prevalence clusters of CKDu have been recorded. Eighty-four groundwater and five surface water samples, covering the selected region, were collected and analyzed for both major anions and cations. The groundwater in the region is mainly of the Ca-Mg-HCO3 type, probably due to the long residence time in fractured hard rock aquifers in this region. Irrespective of the CKDu prevalence, over 50% of samples exceeded the recommended limits for EC/TDS, alkalinity, hardness, and Mg2+ content in groundwater. Water hardness in CKDu clusters was dominated by Mg2+. High fluoride content up to 4.0 mg/L was also found in most groundwater samples from the region. The water quality index (WQI) values indicated that 42% of the groundwater samples in regions with no or low CKDu prevalence and 49% of the samples in regions with high prevalence were poor in quality. The spatial distribution of WQI and fluoride concentration overlapped, indicating the direct influence of fluoride on the groundwater quality in the study region. In addition, regions with higher WQI values overlapped with the CKDu hotspots, indicating the direct impact of groundwater quality on the disease prevalence in the studied river basin. The WQI can be used to effectively demarcate areas with possible groundwater-related health effects in the dry-zone regions of Sri Lanka.

Hydro-geochemical Study of the Coastal Aquifer in Tripoli (Lebanon)

Groundwater geochemistry refers to the general chemical properties of water, particularly groundwater. Precipitation, volatilization, oxidation/reduction, sorption/partition, and complexation are processes involved in the distribution and fate of organic molecules in water. Determining hydrogeochemical facies is a great help for determining relationships and similarities among the chemistry of waters in an aquifer. This study focused on the coastal aquifer of Tripoli (Lebanon) with Mio-Quaternary age. It is considered as a confined aquifer and an important hydraulic reserve for domestic water use in the region. Recently, it underwent an urban development that leads to an increase in water demand causing a decrease in the piezometric level and a high-risk of deterioration to water quality through seawater intrusion and anthropic pollution. To understand the origin of mineralization and the mechanism of water hydro-chemistry variation and to provide a vision to underground water recharge, this study aims to analyze the hydrodynamic, piezometric, and geochemical characteristics of the coastal aquifer. The fluctuation of physicochemical parameters for cool and warm seasons has been studied and monitored for 16 coastal wells during April, May, and June 2020. Results were interpreted by using a statistical analysis called Principal Components Analysis (PCA). Cartographic of groundwater levels and concentrations for nitrate, chloride, sulphate ions, the ratio sulphate/chloride were determined by using SUFFER8 software. It can be noticed that the Mio-Quaternary formation at Tripoli consists of thick sedimentary sandstones and conglomerates with argillaceous roots, which provide significantly high permeability characteristics. It is mainly recharged from precipitations through karstic formations. Chemical analysis shows that bicarbonate ions (HCO3-), characterized by dissolution of carbonate rocks from geological upstream formations of Tripoli, means that the aquifer is subjected to intensive recharge of fresh water and snow melting making a hydrostatic equilibrium facing marine intrusion [1]. High contents of chloride and Sodium are due to anthropic contamination or seawater intrusion. However, Magnesium ion concentration assures this intrusion. Meanwhile, nitrates, sulfates and phosphorus high concentrations are related to wastewater leakage or agricultural activities [2].

Multivariate statistics and hydrogeochemistry of deep groundwater at southwestern part of Bangladesh

Multivariate statistics and GIS alone with geochemical modeling were applied to investigate the hydro-geochemical characteristics of groundwater and their spatial distribution in the deep aquifer system of Bagherpara Upazila, Bangladesh. This Upazila consists of an area of 308.3 km2 and local people mostly rely on groundwater to meet the drinking water requirements. Water samples from one hundred randomly selected deep tube wells (152–198 m) were collected and analyzed for 14 water quality parameters to characterize the hydro-geochemical properties. The groundwater shows slight alkaline in nature throughout the study area. Most of the water samples were turbid and 68% of them failed to meet the drinking water quality standard prescribed by the World Health Organization (WHO). TDS concentration ranges between 280 mg/L and 1040 mg/L, with a mean value of 446.20 (±122.19) mg/L. The general order of cation and anion along the study area were Ca2+>Mg2+>Na+>K+ and HCO3->Cl−>PO43->SO42->NO3- respectively. Carbonate weathering is the dominant process for releasing ions in groundwater. Besides, the ion exchange process is active in the study area, which leads to the reduction of Na+ ions. Gibb's plot suggests a rock dominance inheritance controls the dissolution and precipitation of minerals along with the ion-exchange process, and ultimately dictates the groundwater chemistry. Besides, the Piper diagram showed that Ca2+-Mg2+-SO42- is the dominant water type in 65% of the samples followed by Ca2+-Mg2+–HCO3- water type (35%). The abundance of Ca2+ and Mg2+ ions and the alkaline nature of groundwater indicate mixed geochemical facies and reverse exchange reactions. The principal component analysis (PCA) reveals that weathering and leaching of host rocks was the main natural source, while municipal solid waste dumping, sewage discharge, and fertilizer application could be other anthropogenic factors that affect the groundwater geochemistry. In fine, the chemical characteristics of groundwater were acquired through rock dissolution, percolation, and reverse exchange process.

Hydrogeochemical characterization and evaluation of subsurface water quality in the Proterozoic Cuddapah Basin, Andhra Pradesh, India.

In the current survey, different hydrogeochemical processes governing the geochemistry of aquifers, the usefulness of groundwater for regular consumption, and agricultural purposes were evaluated around the Tummalapalle area. One hundred forty-four borehole locations were chosen to characterize the major physicochemical components of the aquifer water. The analysis results of pH inferred that the groundwater is nominally acidic to basic, and pH ranged from 6.6 to 8.4. The average concentrations of TDS, Ca2+, Mg2+, total hardness (TH), HCO3-, and total alkalinity (TA) are within the allowable limits of potable water quality as prescribed by the Bureau of Indian Standards (BIS) and WHO. However, the average concentrations of Na+, K+, Cl-, and SO42- were all below the permissible limit. All samples were analyzed with the help of Piper and Chadha charts to determine the dominant hydrogeochemical components of groundwater. The dominance of cations in groundwater in this region is in the sequence of Ca2+ > Na+ > Mg2+ > K+, followed by anions HCO3- > Cl- > SO42-. The Gibbs plot analysis suggested the predominance of rock aquifer interaction as the major hydrogeochemical process governing groundwater geochemistry in this region.The water quality index (WQI) of all groundwater samples in the Tummalapalle region was estimated, with 55% of the samples being potable grade. The different irrigation indices were analyzed for the groundwater samples to estimate their desirability for agriculture. The maximum number of water samples was found to be well-suited for cultivation.

Hydrogeochemical and isotopic investigation of the multilayer aquifer system: a case study of the Quaternary and the Campanian aquifers of the Mateur plain, Northern Tunisia

Abstract The Mateur multi-aquifer system, consisting of a Quaternary alluvial aquifer and a Campanian limestone aquifer, is one of the most significant aquifer systems in northern Tunisia, providing domestic and agricultural water supply for the entire Mateur region. The present study aims to unveil the various factors and mechanisms controlling the groundwater chemistry of such a system. Indeed, integrated hydrogeochemical and isotopic approaches are used herein to identify the alluvial and limestone aquifer waters mixing and evolution in the Mateur region. Results show that despite the difference in aquifer lithology, there is little difference in the major ion geochemistry and stable isotope ratios of groundwater within the Mateur plain. Waters from the Quaternary alluvial aquifer are classified into two predominant facies: mixed facies (Ca–Na–SO4–Cl and Ca–Na–HCO3–Cl) and Na–Cl facies. Similarly, waters from the limestone aquifer have also mixed facies (Ca–Na–SO4–Cl) and sodium chloride facies (NaCl). Groundwater δ18O and δ2H values show more homogeneous values along the groundwater flow direction, indicating inter-aquifer mixing processes. Tritium contents of the Campanian aquifer are lower than those of the Quaternary aquifer, indicating a relatively older age or mixture with recent waters. This validates a concept of the hydraulic continuity between the Quaternary aquifer and the Campanian aquifer which is consistent with the geochemical analytical results.

Hydrogeochemical factors controlling the occurrence of chronic kidney disease of unknown etiology (CKDu).

Chronic kidney disease of unknown etiology (CKDu) has posed a serious threat to human health around the world. The link between the prevalence of CKDu and groundwater geochemistry is not well understood. To identify the potential geogenic risk factors, we collected 52 groundwater samples related to CKDu (CKDu groundwater) and 18 groundwater samples related to non-CKDu (non-CKDu groundwater) from the typical CKDu prevailing areas in Sri Lanka. Results demonstrated that CKDu groundwater had significantly higher Si (average 30.1mg/L, p < 0.05) and F- (average 0.80mg/L, p < 0.05) concentrations than those of non-CKDu groundwater (average 21.0 and 0.45mg/L, respectively), indicating that Si and F- were the potential risk factors causing CKDu. The principal hydrogeochemical process controlling local groundwater chemistry was chemical weathering of silicates in Precambrian metamorphic rocks. Groundwater samples were mostly undersaturated with respect to amorphous silica and clay minerals such as talc and sepiolite, which was conducive to silicate weathering and elevated Si concentrations in groundwater. Decreased Ca2+ being facilitated by calcite precipitation and cation exchange between Ca2+ and Na+ favored fluorite dissolution and thus led to high groundwater F- concentrations. Competitive adsorption between [Formula: see text] and F- also enhanced the release of F- from solid surfaces. This study highlights the CKDu potential risk factors regarding groundwater geochemistry and their enrichment factors, which helps in preventing the prevalence of CKDu.

Statistical Characterization of Groundwater Geochemistry in Vein-Type Gold Mines in Korea

맥상 금광상 주변 지하수 등 다양한 지하수의 화학분석 결과를 국내 문헌들로부터 수집하였다. 각 시료를 채취 위치에 따라 금맥 주변의 ‘갱내수’, 광산 지역에 존재하나 금맥과 공간적으로 이격되어 있는 ‘주변수’, 비광화 화강암질암 지역의 ‘일반지하수’, 500 m 이하 심도의 ‘심부지하수’로 구분한 후, 화학분석 결과를 이용하여 일원분산분석, 군집분석, 판별분석을 수행하였다. ANOVA 분석 결과, 갱내수는 다른 그룹의 지하수에 비해 TDS, Ca, SO4 함량이 통계적으로 유의하게 높은 것으로 나타났다. 갱내수의 높은 SO4 함량은 금과 동반되어 산출되는 다양한 황화광물의 존재에 의해, Ca 함량은 광산 내 열극충진광물로 공통적으로 관찰되는 방해석에 기인한 것으로 보인다. 판별분석 결과 도출된 분류함수는 92% 이상의 적중률로 갱내수, 주변수, 일반지하수를 판별할 수 있었다. 통계학적 접근을 통해 도출된 이러한 분류함수는 지하수 화학분석을 통해 미지의 맥상 금광상을 탐사하는데 지표가 될 수 있을 것이다.

Geochemistry and nitrate pollution assessment of groundwater in Djelfa city

Geochemistry and nitrate pollution assessment of groundwater in Djelfa city

HYDROGEOCHEMICAL ANALYSIS AND MODELLING OF GROUND WATER IN KENYA. A CRITICAL LITERATURE REVIEW

Purpose: Hydro geochemistry of groundwater provides a broad, more regionally extensive understanding of groundwater systems. Furthermore, this improved knowledge can be used to create more comprehensive management and conservation plans, and more equitable ground water regulations. The purpose of our study therefore is to analyze and model hydrogeochemical of groundwater in Kenya. Methodology: The paper used a desk study review methodology where relevant empirical literature was reviewed to identify main themes and to extract knowledge gaps. Findings: It was found that there was high concentration iron, zinc and manganese present in groundwater samples in the Sub Catchment. The close proximity of cattle kraals, pit latrines and domestic sewage effluents were found to be the factors that influence and degrade the quality of groundwater. The sanitary survey revealed that the risk to pollution for the boreholes ranged from low to medium but all the shallow wells were in the high-risk category due to the proximity of cattle kraals, pit latrines and domestic waste dumps to these wells. Unique Contribution to Theory and Practice: The study recommended that county government should facilitate the removal of these excess ions from the borehole waters to ensure that the residents are consuming clean water since the concentrations of Na+, Ca2+, Mg2+, F-, Cl and NO3- were found to be elevated in 90 % of the boreholes. Also, there is need for the county government to provide more piped water in the areas for the safety of the residents and avoid overexploitation of the boreholes

Microbial diversity and geochemistry of groundwater impacted by steel slag leachates

To understand long-term impacts of steel slag material on aquifer geochemistry and microbial communities, we conducted four sampling campaigns in the Gier alluvial groundwater (Loire, France). In its northern part, the aquifer flows under a 200,000 m3 steel slag exhibiting high levels of chromium and molybdenum. Geochemical analyses of the water table revealed the existence of water masses with different chemical signatures. They allowed us to identify an area particularly contaminated by leachates from the slag heap, whatever the sampling period. Water samples from this area were compared to non-contaminated samples, with geochemical characteristics similar to the river samples. To follow changes in microbial communities, the V3-V4 region of 16 s rRNA gene was sequenced. Overall, we observed lower diversity indices in contaminated areas, with higher relative abundances of Verrucomicrobiota and Myxococcota phyla, while several Proteobacteria orders exhibited lower relative abundances. In particular, one single genus among the Verrucomicrobiota, Candidatus Omnitrophus, represented up to 36 % of total taxon abundance in areas affected by steel slag leachates. A large proportion of taxa identified in groundwater were also detected in the upstream river, indicating strong river-groundwater interactions. Our findings pave the way for future research work on C. Omnitrophus remediation capacities.

Hydrogeochemistry of the groundwater system of the transboundary basement and volcanic aquifers of the Bulal catchment, Southern Ethiopia

The evaluation of groundwater geochemistry of transboundary aquifers has an important role in the management and sustainable use of groundwater resources in arid and semi-arid regions. This study presents the results of an integrated hydrogeochemical study of the Bulal transboundary aquifers located in the Borena zone, along the Ethiopia-Kenya border. The main aquifers are basic volcanic rocks, subordinate felsic pyroclastic deposits, and metamorphic basement rocks. These aquifers are overlain by alluvio-lacustrine sediments, eluvial soil and regolith. The groundwaters are dominated by Na+ and HCO3− and mixed water types. Silicate weathering and evaporation are the dominant hydrogeochemical processes controlling the chemistry of the groundwaters in most parts of the catchment. However, dissolution of evaporitic minerals might have also played a significant role in adding major ions into the groundwater system. Groundwater in the volcanic aquifers are Na–HCO3, Ca–Mg–HCO3, Na–Ca–HCO3 and Na–Cl–SO4 water types while Ca–Mg–HCO3, Na–Ca–Cl–SO4 and Ca–Mg–SO4 water types are dominant in the metamorphic basement aquifers. The groundwater in the catchment mainly evolved from Na–HCO3 in the west, Ca–Mg–HCO3 in the north, and Na–Ca–Cl–SO4 in the central east and southeast to Na–Ca–HCO3 type in the southern low-lying areas along the groundwater flow direction. The study has significant implications for the management of groundwater quality in the region.

Geochemistry of groundwater and metal(loid) behavior in the costal aquifers of the Maharlu Lake, Iran.

Groundwater in coastal aquifers of the Maharlu Lake, southern Iran, has suffered from quality degradation and salinity increases in recent decades. These aquifers are important sources for drinking and agricultural uses in area around the lake. Hydrogeochemical analyses were carried out to identify the geochemical processes controlling groundwater chemistry and heavy metal concentrations in the coastal aquifer of the Maharlu Salt Lake. A total number of 54 water samples (45 samples from three coastal aquifers and 9 water samples from lake water) were collected for laboratory analysis of major ions and heavy metals three times from November-2014 to July-2015. In addition, physiochemical parameters of temperature, electrical conductivity, pH, and redox potential were measured in the field. The findings indicate three major controls of groundwater chemistry in the coastal aquifers of the Maharlu Lake including (1) lake water intrusions, (2) evaporites and carbonate dissolution-precipitation, and (3) input of organic matter probably linked to the seepage of domestic sewage with resulting sulfate reduction. In contrast, dissolution of minerals in surface sediments and direct evaporation of groundwater in the coastal aquifers seem to be insignificant based on geochemical ratios and water table depth. Concentrations of B, Li, Co, Cr, Cu, Ni, and U increase, but Zn concentrations decrease in groundwater due to the lake water intrusions into the costal aquifers. Gypsum dissolution and consequent carbonate reactions cause B, Co, Cr, Cu, Ni, Zn, and U enrichment in the groundwater samples. These findings can provide water managers and local authorities with a comprehensive framework of the coastal groundwater geochemistry, allowing a better understanding of the effects of current management practices and the implementation of mitigation approaches such as reduction of groundwater extraction to limit further lake saltwater intrusion and water resources deterioration.

Relationships between geomorphological features and groundwater geochemistry in the upper and middle basin of Las Peñas stream, Pampean Mountains, Córdoba. Argentina

Relationships between geomorphological features and groundwater geochemistry in the upper and middle basin of Las Peñas stream, Pampean Mountains, Córdoba. Argentina

Hydrogeochemical Survey along the Northern Coastal Region of Ramanathapuram District, Tamilnadu, India

Ramanathapuram is a drought-prone southern Indian district that was selected for conducting a hydrogeochemical study. Groundwater samples from 40 locations were collected during January 2020 (pandemic interdiction according to COVID) and January 2021. The hydrogeochemical properties of the groundwater samples were evaluated and compared with drinking water regulations to assess their water quality. The order of cation dominance was as follows: Na+ &gt; Ca2+ &gt; K+ &gt; Mg2+ in January 2020 and Na+ &gt; Ca2+ &gt; Mg2+ &gt; K+ in January 2021 with respect to the mean value. The order of anion dominance was as follows: Cl− &gt; HCO3− &gt; SO42− &gt; NO3− &gt; F− in January 2020 and Cl− &gt; SO42− &gt; HCO3− &gt; NO3− &gt; F− in January 2021 with respect to the mean value. In the study area, the southern coastal region was identified as a groundwater-polluted zone through spatial analysis based on all analysis results. The irrigation water quality was analyzed using various calculated indices, such as Na% (percent sodium), SAR (sodium absorption ratio), PI (permeability index), MgC (magnesium risk), RSC (residual sodium concentration), and KI (Kelly ratio), demonstrating the suitability of the groundwater for irrigation in most parts of the study area. This was also confirmed by the Na% vs. EC Plot, USSL, and Doneen’s Plot for PI. In addition, the WQI results for drinking water and irrigation confirmed the suitability of the groundwater in most parts of the study area, except for the coastal regions. The dominant hydrogeologic facies of Na+-Cl−, Ca2+-Mg2+-SO42−, and Ca2+-Mg2+-Cl− types illustrated by the Piper diagram indicate the mixing process of freshwater with saline water in the coastal aquifers. Rock–water interaction and evaporation were the main controllers of groundwater geochemistry in the study area, as determined using the Gibbs plot. Ion exchange, seawater intrusion, weathering of carbonates, and the dissolution of calcium and gypsum minerals from the aquifer were identified as the major geogenic processes controlling groundwater chemistry using the Chadha plot, scatter plot, and Cl−/HCO3− ratio. Further, multivariate statistical approaches also confirmed the strong mutual relationship among the parameters, several factors controlling hydrogeochemistry, and grouping of water samples based on the parameters. Appropriate artificial recharge techniques must be used in the affected regions to stop seawater intrusion and increase freshwater recharge.

Laboratory Simulation of Groundwater Along Uranium-Mining-Affected Flow Paths Near the Grand Canyon, Arizona, USA

Mining of volumetrically small, but relatively enriched (average 0.6% U3O8) breccia pipe uranium (BPU) deposits near the Grand Canyon, Arizona, USA has the potential to affect groundwater and springs in the area. Such deposits also contain base metal sulfides that can oxidize to generate acid mine drainage and release trace metals. In this study, sequential batch experiments were conducted to simulate the geochemistry of local shallow groundwater that contacts BPU ore and then moves downgradient through sedimentary strata. The experiments simulated shallow groundwater in a carbonate aquifer followed by contact with BPU ore. The experiments subsequently simulated contact with sedimentary rocks and changing oxygen availability. Concentrations of several contaminants of potential concern became substantially elevated in the waters exposed to BPU ore, including As, Co, Ni, U, and Zn, and to a lesser extent, Mo. Of these, Co, Mo, Ni, and U were minimally attenuated by downgradient processes, whereas Zn was partially attenuated. Sb and Tl concentrations were more moderately elevated but also generally minimally attenuated. Although the mixture of elements is particular to these BPU ore deposits, sulfide oxidation in the ore and carbonate buffering of pH by sedimentary rocks generates patterns of water chemistry common in acid mine drainage settings. Ultimately, downgradient concentrations of elements sourced from BPU ore will also be strongly influenced by non-geochemical factors such as the quantities of water contacting BPU materials, heterogeneity of materials along flow paths, and mixing with waters that have not contacted BPU materials.

Strontium and radium occurrence at the boundary of a confined aquifer system

Aquifers are susceptible to contamination by naturally occurring metals and radionuclides that limits the quantity of groundwater available for drinking. The Midwestern Cambrian-Ordovician aquifer system (MCOAS) is an important drinking water source in the North Central region of the U.S., but can contain elevated levels of geogenic radium (Ra) and strontium (Sr). Here, the occurrence of Ra and Sr is investigated with respect to natural groundwater evolution and water-rock interactions using a multi-isotope approach (δ18O, δ2H, δ34SSO4, 87Sr/86Sr, and [234U/238U]), in a portion of the MCOAS that straddles regionally unconfined and regionally confined conditions. Hierarchical cluster analysis reveals three distinct groups of groundwater geochemistry, evolving from a young (<10,000 years) HCO3−- dominant groundwater located upgradient to old (>10,000 years) SO42− and Cl−-dominant groundwater located downgradient. Strontium and Ra concentrations are highest downgradient, where extreme [234U/238U] disequilibrium indicates increased water-rock interactions due to local confinement or a stagnant groundwater zone. Geochemical conditions evolve as a consequence of water-rock interaction, resulting in Ra and Sr mobilization mechanisms including enhanced mineral dissolution and weathering, and decreased sorption efficiency due to competitive sorption and the absence or dissolution of iron and manganese (hydr)oxides with sorbed Ra and Sr. Relative to redox processes, ‘mixed’ redox samples have the highest median Sr and Ra concentrations, where young, oxic groundwater mixes with old, anoxic groundwater over long open boreholes. Isotopic results (δ18O and δ2H, 87Sr/86Sr) indicate these wells with long open boreholes are receiving more of the old, deep groundwater elevated in Ra and Sr, suggesting that well construction is an important consideration for Ra and Sr occurrence. The presented framework can be used to examine the occurrence of geogenic contaminants with respect to recharge history, water-rock interactions, and evolving geochemical conditions in other aquifer systems with a range of groundwater residence times and geochemistry.

Geochemical Characteristics and Quality Appraisal of Groundwater From Huatugou of the Qaidam Basin on the Tibetan Plateau

Groundwater is the foremost water resource for various purposes in arid regions. The extremely arid climate makes groundwater geochemistry there evolve faster in a short distance and water supply face higher pressure of poor geochemical quality. A hyper-arid watershed on the Tibetan Plateau was investigated to get insights into the geochemical signature, formation, and quality suitability of groundwater there. A total of 13 surface water samples and 32 phreatic groundwater samples were collected for hydrogeochemical analysis. The results showed groundwater had better hydrogeochemical quality than surface water and was more favorable for human society utilization. Groundwater was dominated by relatively fresh hydrochemical facies of HCO3–Ca, mixed HCO3–Na·Ca, and mixed Cl–Mg·Ca type with more than 93% of samples having the TDS below 1,000 mg/L. Most of the groundwaters were soft fresh water (84.38%) and had excellent to good quality (93%) for domestic purposes based on entropy-weighted water quality index evaluation. Groundwater was suitable for irrigation in terms of sodium and permeability hazard, but the potential salinity hazard should be concerned. The poor geochemical quality of groundwater was ascribed to the salinity caused by strong evaporation. Natural rock–water interactions including silicate weathering, carbonate dissolution, and cation exchange were still the predominated processes governing groundwater chemical composition. The influence of human activities was very limited. Groundwater resource exploitation and management should mainly consider the salinity and strong evaporation due to shallow water depth.

Assessment of Groundwater Geochemistry and Its Suitability for Drinking and Irrigation Practices in the Chakwal District, Punjab, Pakistan

Assessment of Groundwater Geochemistry and Its Suitability for Drinking and Irrigation Practices in the Chakwal District, Punjab, Pakistan

Groundwater geochemistry evolution and geogenic contaminants in the Sulaimani-Warmawa Sub-basin, Sulaimani, Kurdistan Region, Iraq.

Evolution of groundwater geochemistry in the Sulaimani-Warmawa Sub-basin in the Kurdistan Region of Iraq has been investigated using hydrogeochemical and isotopic methods. This is a semiarid region with seasonal precipitation in winter. Water chemistry generally evolves from Ca-HCO3 groundwater type close to the basin boundaries towards Ca-Mg-HCO3 groundwater type close to the Tanjero River along the axis of the basin. Some samples have increased concentrations of Na, Cl, and SO4 as a consequence of dissolution of halite and gypsum embedded in carbonates. Values of pH are slightly alkaline or alkaline, and redox parameters indicate a moderately reducing environment. Isotopes δ2H and δ18O indicate recharge from winter precipitation with no evaporation. Values of dissolved 13C(DIC) correspond to equilibrium with carbonates and C4 plants as the source of CO2. Values of 87Sr/86Sr in groundwater are in a good agreement with carbonate dissolution as a principal process. The principal geogenic contaminant is Ba with concentrations up to 0.383mg/L. Dissolved concentrations of other geogenic contaminants such as As, F, Mn, and Cr are low or below the detection limit as expected based on their low contents in carbonate rocks. Inverse geochemical modeling on selected profiles calibrated using δ13C values provided mass transfer coefficients for possible geochemical reactions. Future work should focus on interactions in the hyporheic zone of the Tanjero River.

Comparison of groundwater composition from the Monturaqui and Punta Negra Basins, northern Chile: implications for porphyry copper exploration

Groundwaters recovered from the Salar de Punta Negra and Monturaqui basins in the Atacama Desert of northern Chile exhibit distinctly different isotopic, major, trace, and porphyry copper elemental compositions related to contrasting morphostructural, geochemical, and hydrodynamic settings. Comparison of these distinct groundwater signatures with groundwaters from known porphyry copper deposits (Salar de Hamburgo and Spence Deposit), can be used to determine if either basin might be prospective for porphyry copper mineralization. Groundwaters within the Punta Negra Basin exhibit geochemical characteristics consistent with other closed basin settings throughout the arid Andes. Elemental and isotopic compositions within the Punta Negra Basin reflect closed basin evaporitic processes consistent with the hyperarid, volcanic setting of the central Andes. Pathfinder metals and isotopic compositions are not consistent with porphyry copper type mineralization as described for groundwaters within the Salar de Hamburgo Basin, and the Spence Deposit. Within the Monturaqui Basin the geochemical composition of groundwaters are characteristic of diffuse hydrothermal activity. Sulfur isotopic composition within the waters of the northern Monturaqui Basin exhibit δ 34 S CDT isotopic signatures that fall within the range for sulfide mineralization as reported for groundwaters in and around the Spence Deposit and the Salar de Hamburgo. However, porphyry copper related elements within the Monturaqui Basin are impoverished relative to groundwaters of the Spence and Escondida Deposit. Such impoverishment in porphyry related elements, taken in conjunction with enriched δ 13 C PDB compositions, elevated groundwater temperatures, groundwater compositions dominated by HCO 3 , SO 4 , and Si, and the proximity of the Monturaqui Basin to the current magmatic arc are consistent with a volcanic hydrothermal origin. In summary, the groundwater geochemistry of the Monturaqui and Punta Negra Basins are not indicative of porphyry copper-type mineralization. Thematic collection: This article is part of the Hydrochemistry related to exploration and environmental issues collection available at: https://www.lyellcollection.org/cc/hydrochemistry-related-to-exploration-and-environmental-issues