Representative Groundwater Samples Research Articles

Using Clustering, Geochemical Modeling, and a Decision Tree for the Hydrogeochemical Characterization of Groundwater in an In Situ Leaching Uranium Deposit in Bayan-Uul, Northern China

Uranium extraction through the in situ leaching method stands as a pivotal approach in uranium mining. In an effort to comprehensively assess the repercussions of in situ uranium leaching on groundwater quality, this study collected 12 representative groundwater samples within the Bayan-Uul mining area. The basic statistical characteristics of the water samples showed that the concentrations of SO42− and total dissolved solids (TDS) were relatively high. Through the use of cluster analysis, the water samples were categorized into two distinct clusters. Seven samples from wells W-d, W-u, N01, W10-2, W08-1, W10-1, and W13-1, situated at a considerable distance from the mining area, were grouped together. Conversely, five samples from wells W08-2, W13-2, W01-1, W02-2, and the pumping well located in closer proximity to the mining area, formed a separate cluster. A decision tree-based machine learning approach was employed to discern the influence of various hydrochemical indicators in forming these clusters, with results indicating that SO42− exerts the most substantial influence, followed by Ca2+. The mineral saturation indices from geochemical modeling indicated that, as the distance from the mining area increased, the trend of calcium minerals changed from dissolution to precipitation; iron minerals were in a precipitation state, and the precipitation trend was gradually weakening. In light of these findings, it is clear that in situ uranium leaching significantly impacted the groundwater in the vicinity of the mining area. The prolonged consumption of groundwater sourced near the study area, or its use for animal husbandry, poses potential health risks that demand heightened attention.

Analysis of Heavy Metal Sources in Groundwater and Assessment of Health Risks: An Example from the Southwest Sub-basin of the Shiqi River

In order to explore the sources of pollution and health risk profile of heavy metal elements in groundwater, 41 sets of representative groundwater samples from the southwest sub-basin of the Shiqi River were examined for 10 heavy metal elements (As, Cr, Cd, Al, Cu, Zn, Ni, Co, Mn, and Hg), and correlation analysis and principal component analysis were used to resolve the possible sources of heavy metal contamination in groundwater in the study area. The concentration characteristics and health risk levels of the 10 heavy metals were assessed using the single-factor contamination index (Pi), the Nemerow comprehensive contamination index (PN), and the health risk model. The results showed that:① the average values of heavy metal elements of the groundwater in the study area all met the limit of the class Ⅲ water standard in the quality standard for groundwater (GB/T 14848-2017); only the maximum value of Al was exceeded, followed by a large variation in the concentrations of Al, Mn, and Cr. The heavy metal element with the largest average contribution was Al (65.74%). ② The results of the single-factor contamination index evaluation showed that only the heavy metal element Al exceeded the cleaning level, and the results of the Nemerow comprehensive contamination index evaluation showed that the study area was basically at low pollution levels, and the quality of groundwater was good. ③ The results of the multivariate statistical analysis showed that Zn, Co, and Mn were from mixed sources consisting of geological formation and domestic waste; Al, As, and Cu were from agricultural sources; Cd, Cr, and Ni were from industrial sources; and Hg came from long-range atmospheric transport. ④ The health risk values for all heavy metals in the study area were within acceptable limits, with higher health risk values for children than for adults from the drinking water route, lower health risk values than in adults from the dermal route, and higher health risk values for heavy metals from the drinking water route than those from the dermal route, indicating that the drinking water route was the main route of exposure to heavy metals.

Combining hydrogeochemistry, statistics and explorative mapping to estimate regional threshold values of trace elements in groundwater (Sardinia, Italy)

Assessing geochemical baseline and threshold values of potentially toxic elements at adequate scales is fundamental for distinguishing geogenic contamination from anthropogenic pollution in groundwater. This study was aimed to estimate the regional threshold values of Li, Be, B, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Mo, Ag, Cd, Sb, Te, Ba, Hg, Tl, Pb, Bi, and U (elements listed according to atomic numbers) in groundwater, compare results to guidelines established for drinking water and the protection of groundwater from contamination, investigate the geographical distribution of trace elements, and assess the potential influence of water-rock interaction.A pre-selection aimed at excluding groundwater samples affected by known anthropogenic activities was carefully carried out based on hydrogeochemical characteristics of waters and considering the potential sources of contamination. The resulting dataset was comprised of 1227 groundwater sampling sites located in Sardinia (Italy). Undetected values were treated using the Regression on Order Statistics method. For elements containing >75 % of undetected values and/or a limited number of samples in the dataset (Li, Rb, Sr, Mo, Ag, Te, Tl, Sb, Hg and Bi), the threshold values were estimated using either the 95th or 97.7th percentiles. For the other elements the mean + 2SD (Standard Deviation), the median + 2MAD (Median Absolute Deviation), and the TIF (Tukey Inner Fence) estimators were also calculated.Geochemical maps allowed to recognize the threshold value of each element at different scales. Regional threshold values of the regulated elements B, Al, V, Cr, Cu and Cd in groundwater were below the Italian and World Health Organization drinking water guidelines, whereas Mn and As were above them. Regional threshold values estimated with TIF exceeded the drinking water guidelines for Ni, Se, Pb and U.Results of this study showed that high concentrations of trace elements in groundwater were primarily dependent on the corresponding amount in parent materials with which the groundwater came into contact. Physical-chemical parameters and geochemical characteristics may contribute to enhancing concentrations of some trace elements in groundwater, e.g. As via reductive dissolution of Fe(III)-Mn(IV) hydroxides/oxides, Pb via formation of stable aqueous complexes, and other elements via adsorption onto fine particles with size below 0.4 μm (i.e. the pore size of filters used).Maps drawn on the centered log-ratio (clr) transformation of hydrogeochemical data, following the CoDA (Compositional Data Analysis) approach, allowed to pinpoint critical areas to be investigated in more detail. For each geological complex, groundwater samples likely representing nearly pristine conditions were identified. The monitoring of these representative groundwater samples may help to pinpoint eventual changes in environmental conditions.

Cadmium geochemistry and groundwater pollution status evaluation using indexing and spatial analysis for Keffe community and Environs Sokoto Basin, North Western Nigeria

Representative groundwater samples were collected from the Kaffe community and environs to evaluate the concentrations and geochemical constraints for mobilizing cadmium (Cd) and selected heavy metals. Field-based in-situ measurements of physicochemical parameters were combined with Atomic Absorption Spectrophotometer analysis of dissolved elemental concentrations. Pollution indices (i.e. heavy metal pollution index; HPI, heavy metal evaluation index; HEI, contamination degree; Cd, metal index; MI, synthetic pollution index; SPI, ecological risk index; ERI and Nemerow index; NI) evaluations highlighted the levels of heavy metals in the groundwater. Cadmium and iron (Fe) concentrations exceeded the recommended limits in 97% of the analysed samples, with an average pH of 6.3. Strong positive correlations were observed between cadmium and the computed pollution indices (p 0.774 to p 0.100), suggesting significant Cd pollution of the groundwater. Components analysis grouped Cd, Fe, and the pollution indices in the first PC. This was favourably compared to the correlation analysis result. Cluster analysis categorized Cd, Zn and pH in the first cluster consistent with the suggested dissolution and enrichment of Cd and Zn in the groundwater under similar geochemical conditions. The study area is medium and moderately polluted based on HPI, HEI, Cd, and NI.

Hydrogeochemical evaluation and geospatial distribution modeling of the major ion chemistry of groundwater and their suitability for drinking and irrigation in Lagelu, Southwestern Nigeria

Shallow groundwater is an essential resource for domestic, agricultural, and small-scale industrial uses in Lagelu in Oyo State, Southwestern Nigeria. A total of 20 representative groundwater samples were collected from different hand-dug wells and analyzed for the major cations, anions, and heavy metals to establish their suitability for drinking and irrigation. Geospatial variation maps of the major cations and anions were produced using the inverse distance weighted algorithm. The results of the respective concentrations of pH, TDS, EC, HCO3−, NO3−, SO42−, Cl−, PO42−, Ca2+, Mg2+, Na+, K+, Zn2+, Cu+, Pb2+, and As+ except Fe2+ are within the recommended range set by the World Health Organization (WHO) and Nigerian Industrial Standards for Drinking Water Quality (NSDWQ). Based on the hydrogeochemical facies, the groundwater belongs to Na+–K+–Cl−–SO42−, and Ca2+–Mg2+–Cl−–SO42− water types. Gibb’s diagram shows that the interaction of rocks and water dominate the processes that control the ionic compositions of the groundwater due to rock weathering and dissolution. The correlation matrix that specifies the ion concentration relationship showed that TDS, K+, and Fe2+ strongly correlate positively with EC, Na+, and Ca2+, respectively. CO32−, Na+, and Cu moderately correlate positively with Cl−, Mg2+, and pH, respectively. The indices used to determine groundwater suitability for irrigation classified over 90% of the samples as suitable for irrigation.

Assessment and characterisation of groundwater quality in Akure metropolis, southwestern Nigeria

The geology of an area plays a significant role in the chemistry of groundwater. The quality of groundwater can also be adversely affected by anthropogenic activities if not properly monitored. The composition of groundwater in Akure was assessed and characterised in order to determine the chemical behavior of the groundwater system within the city. A total of thirty-six representative groundwater samples were randomly collected within Akure metropolis. The chemical composition of the water samples was analysed and determined using AAS, flame photometry and titration methods. The analysis of the results showed that the chemical concentrations of EC ranged from 35.5 to 1670.0µS/cm; TDS (in mg/l) ranged from 5.0 to 1700.0; Na+(1.0–122.0); K+(1.2–156.7); Ca2+(1.2–17.3); Mg2+(3.9–6.4); Fe3+(0.03–1.03); HCO3− (0.0–622.5); NO3−(0.01–0.25); Cl−(1.99–216.4); SO42−(22.6–`873.9); Mn2+(0.05–0.30); Zn2+(0.06–0.78); Cu2+(0.02–0.32); Pb2+(0.01–0.18); Ni2+(0.0–0.02); Cr3+(0.02–0.32); and Se2+(0.06–0.37). Statistical evaluation of the data showed that the water samples collected within the centre of the ancient city as well as the samples obtained from downstream of the major river draining the city have elevated EC and TDS higher than the WHO and NIS recommended limits. Further evaluation of the results by piper diagram, Gibb’s plot and Chadha classifications showed that the chemistry of the groundwater system in Akure metropolis is largely dominated by rock water interactions. The primary character of the water falls within the alkali metals exceeding alkaline earth metals and strong acidic anions exceeding weak anions. The indicates that the groundwater system in the study area has salinity challenges for both domestic uses and irrigation purposes.

Exploring Machine Learning Models in Predicting Irrigation Groundwater Quality Indices for Effective Decision Making in Medjerda River Basin, Tunisia

Over the last years, the global application of machine learning (ML) models in groundwater quality studies has proved to be a robust alternative tool to produce highly accurate results at a low cost. This research aims to evaluate the ability of machine learning (ML) models to predict the quality of groundwater for irrigation purposes in the downstream Medjerda river basin (DMB) in Tunisia. The random forest (RF), support vector regression (SVR), artificial neural networks (ANN), and adaptive boosting (AdaBoost) models were tested to predict the irrigation quality water parameters (IWQ): total dissolved solids (TDS), potential salinity (PS), sodium adsorption ratio (SAR), exchangeable sodium percentage (ESP), and magnesium adsorption ratio (MAR) through low-cost, in situ physicochemical parameters (T, pH, EC) as input variables. In view of this, seventy-two (72) representative groundwater samples have been collected and analysed for major cations and anions during pre-and post-monsoon seasons of 3 years (2019–2021) to compute IWQ parameters. The performance of the ML models was evaluated according to Pearson’s correlation coefficient (r), the root means square error (RMSE), and the relative bias (RBIAS). The model sensitivity analysis was evaluated to identify input parameters that considerably impact the model predictions using the one-factor-at-time (OFAT) method of the Monte Carlo (MC) approach. The results show that the AdaBoost model is the most appropriate model for predicting all parameters (r was ranged between 0.88 and 0.89), while the random forest model is suitable for predicting only four parameters: TDS, PS, SAR, and ESP (r was with 0.65 to 0.87). Added to that, this study found out that the ANN and SVR models perform well in predicting three parameters (TDS, PS, SAR) and two parameters (PS, SAR), respectively, with the most optimal value of generalization ability (GA) close to unity (between 1 and 0.98). Moreover, the results of the uncertainty analysis confirmed the prominent superiority and robustness of the ML models to produce excellent predictions with only a few physicochemical parameters as inputs. The developed ML models are relevant for predicting cost-effective irrigation water quality indices and can be applied as a DSS tool to improve water management in the Medjerda basin.

Geoelectrical and Geochemical Investigations of Selected Dumpsites for Potential Groundwater Contamination in Gusau, Zamfara State, Nigeria

Groundwater contamination has been a worldwide phenomenon. In this research, geoelectric and geochemical surveys were carried out on three active dumpsites in Gusau metropolis for detection of groundwater contamination. Vertical electrical Soundings (VES) were conducted on the dumpsites using Schlumberger array with maximum current electrode separations of 180 m. Five VES were conducted on each dumpsite making a total of fifteen VES along three profiles. Thirty five (35) points were assessed from three wastes dumpsites using portable XRF equipment for the in-situ testing while fifteen (15) representative groundwater samples collected were taken to the laboratory for hydro-geochemical analysis. The field data obtained from VES was analyzed using WinGlink software. The VES results revealed three subsurface layers. The topsoil has resistivity ranging from 1.5Ωm to 48.2 Ωm while the thicknesses vary from 0.47 m to 3.37 m across the profiles. The second layer’s resistivity varies from 5.4 Ωm to 144.35 Ωm and their thicknesses’ ranges from 1.36 m to 16.93 m. The third geoelectric layer has resistivity from 70.0 Ωm to 6003.0 Ωm. The geoelectric results revealed that the top soils in all the dumpsites were characterized by very low resistivity depicting possible pollution and contamination. Environmental pollution models applied to the geochemical dataset revealed Zn, Pb and Cu as moderately contaminants which generally indicated severe potential contamination in the investigated area. While other analytic parameters such as Mn, Cr, Ni and Fe showed low contamination factors. Hydro chemical analysis showed that pH values recorded from the water samples ranged between 7.26 to 8.12 with mean value of 7.50, whereas, recorded Total dissolve solid (TDS) ranged between 377 to 1393mg/L with average concentration of 751.27mg/L. Findings from the study indicated that there may be possible contamination of shallow groundwater system in the nearest future if proper mitigation measures are not taken into consideration at the dumpsites.

Isotopic signatures and hydrochemistry in assessing groundwater occurrence in the desert environs west Qena, Egypt

BackgroundDeveloping the desert zone outside the flood plain of the Nile River and targeting the reclamation of about 12,500 feddan in the desert environs of Qena governorate are considered one of the top priorities of both government and the private sectors. The present study is based on qualitative analyses of the groundwater of the Quaternary aquifer in the desert environs west Qena. Groundwater was chemically and isotopically analyzed to determine the origin of groundwater and assess its occurrence.ResultsThe obtained results indicate that the Quaternary aquifer represents the most important groundwater aquifer in the area. The water level ranges from + 40 to + 67 m above sea level. The groundwater movement direction in the study area is mainly from southeast to northwest direction, with some local flow groundwater directions from Nile River at the north to old alluvial plain and desert environs at the south. The hydraulic conductivity of the aquifer is determined from the pumping test range from 17.63 to 42.86 m/day, with an average value of 27.04 m/day, while the transmissivity ranges between 2142.8 and 1128.3 m2/day, with an average value of 1456.74 m2/day. The total dissolved solids range from 589 to 3832 mg/L. Isotopic analysis (oxygen eighteen and deuterium) of fifteen groundwater samples was carried out to define the recharge source of the Quaternary aquifer. The groundwater isotopic data reflect variability in recharge conditions during different ages and different climatic regimes. According to the minor and trace elements concentration and US Salinity Laboratory Staff nomogram, most water samples are suitable for drinking purposes, domestic use and irrigation.ConclusionThe current research concluded that from the foregoing hydrological study and the determined values of hydraulic conductivity and transmissivity, the Quaternary aquifer is classified as ranging between moderate and high potential aquifer. The high potentiality of the aquifer is detected close to the Nile River. In addition to the representative groundwater samples showing the isotope signature of the Nile River sample, this means that all these wells have the same source of recharge (meteoric water of the Nile River).

Appraisal of the Quality Parameters of the Groundwater used for Domestic and Irrigation Purposes in the Hard Rock Aquifer System of the Vasishta sub- basin of the Vellar River, Tamil Nadu


 
 
 
 This article presents an appraisal of the quality of groundwater in the hard Received in revised form: 15.07.2021 rock aquifer system of the Vasishta sub basin, of the Vellar River Basin. Seventy nine representative groundwater samples were collected from dug and bore wells which are intensively used for domestic and irrigational purposes. The physical parameters viz. PH, EC and TDS were estimated in the field using a portable multiparameter meter. The groundwater samples were transported to the laboratory for measuring major ionic concentrations viz, Ca, Mg, Na, K, CO3, HCO3, Cl, SO4, F and NO3. The hydrochemical data were graphically projected and spatial temporal thematic maps generated with reference to the World Health Organization (WHO) and Bureau of Indian (BIS) Standards. The peoples living in the sub basin engage in agricultural activities where the groundwater availability is sufficient. The groundwater is a major source for meeting their basic needs, such as for domestic, irrigational and industrial purposes. Good correlation is exhibited between EC and TDS Cl, SO4.Cl exhibits good correlation with Mg and Ca (0.817), (0.751) indicating leaching of secondary salts. TDS and EC showed strong correlation with Cl, SO4. Clustering groundwater samples based on their similarity is known as Q-mode type clustering method. Spatial and temporal maps of the water quality index reveal that the majority of the groundwater samples fall under the categories excellent to good.
 
 
 

Seasonal Variations in Groundwater Quality and Hydrogeochemistry in the Endemic Areas of Chronic Kidney Disease of Unknown Etiology (CKDu) in Sri Lanka

Groundwater quality and geochemical processes were investigated in the endemic areas of chronic kidney disease of unknown etiology (CKDu) in Sri Lanka. Representative groundwater samples (n = 60) were collected from 30 dug wells located in the Anuradhapura district, over the dry and wet seasons. The samples were analyzed for pH, electrical conductivity (EC), total dissolved solids (TDS), alkalinity, major cations and major anions. Calcium-magnesium-bicarbonate ion combinations are predominant in this groundwater, and the simultaneous occurrence of high hardness (382–394 mg/L as CaCO3), alkalinity (364–379 mg/L as CaCO3) and ionicity is a salient characteristic. Alkalinity, TDS, hardness, and magnesium exceeded the safe limits for drinking in over half of the samples, regardless of the season. The major ion chemistry (Ca2+, Mg2+, Na+ and HCO3−) is primarily governed by the weathering of carbonate and silicate minerals, ion exchange, and evaporation which is accelerated by the semi-arid climate. Fluoride and chloride inputs are regulated by dissolution of fluoride-bearing minerals and anthropogenic causes, respectively. Saturation indices suggested supersaturation of carbonates and silicates, and undersaturation of evaporites and fluorite. Persistent high ionicity, and hardness of groundwater that is seldom impacted by seasonal variations might be playing a vital role in the genesis of CKDu.

Quali-quantitative considerations on low-flow well purging and sampling

This article deals with both the main advantages and issues related to groundwater purging and sampling that are usually carried out through the so-called low-flow methodology or with the method based on the purging of 3-5 well volumes, which is still widely used in environmental monitoring. A review of the recent literature concerning the technical characteristics, innovations and modelling related to low-flow sampling is presented. The aim is to provide to the reader a broad overview on this specific field application and offer a new vision, which considers two aspects: 1. The qualitative aspect, relating to the representativeness of the sample taken through a correct purging of the monitoring well and the consequent correct interpretation of hydrochemical data; 2. The quantitative aspect, related to the possibility of using water level data during purging and low-flow sampling operations to estimate the soil horizontal hydraulic conductivity, without further investigations. Low-flow sampling methodology can be very useful especially for alluvial aquifers, providing representative samples of groundwater and hydrodynamic characteristics of the aquifer, with reduced costs and times. These two aspects are both important in the context of an environmental monitoring plan for a potentially contaminated site.

Contamination level, source identification and health risk evaluation of potentially toxic elements (PTEs) in groundwater of an industrial city in eastern India.

The present investigation explores the spatial and seasonal variations in potentially toxic element (PTEs) concentrations and contamination level assessment of groundwater samples in and around the Asansol industrial city, eastern India. The representative samples of groundwater from 24 different locations were analyzed for pH, electrical conductivity (EC), total dissolved solids (TDS), total hardness (TH) and PTEs, e.g., Pb, Cu, Cd, Zn, Fe and Cr for pre-monsoon and post-monsoon. The pH level of examined groundwater samples is under the desirable limit with few exceptions (S5, S11 and S16 in pre-monsoon and S12 in post-monsoon). The recorded values for Pb, Cd, Fe and Cr in many sampling stations found higher than the prescribed limits of Indian standards (IS 10500: 2012) in both the seasons. The mean contamination factor (Cf) for PTEs in the groundwater is in the order of Cr > Fe > Cd > Pb > Cu > Zn and Fe > Cr > Cd > Pb > Cu > Zn, with mean contamination index (Cd) value of 2.83 and 2.72 in pre-monsoon and post-monsoon season, respectively, indicating moderate level of contamination in the examined area. Geospatial depiction of HPI values shows high level of contamination during pre-monsoon (58.3% sampling sites) and post-monsoon (45.8% sampling sites) in majority of sampling sites. Further, application of multivariate statistical analysis ascertains that the PTEs in groundwater are majorly derived from anthropogenic activities such as opencast mining, thermal power plants, iron and steel industries, sponge iron and other metallurgical industries, and leachate from urban and industrial wastes along with limited contribution from geogenic and lithogenic sources. The health risk assessment demonstrates that the non-carcinogenic risk (due to PTEs) in adults is in the sequence of Cr > Cd > Pb > Fe > Cu > Zn, while for children the order is Cr > Pb > Cd > Fe > Cu > Zn for both the seasons. The results also reveal higher chance of occurrence of carcinogenic risk due to Cr (ILCR > 1.0E-04) for children and adults in both the seasons.

Integrated approach for the evaluation of groundwater quality through hydro geochemistry and human health risk from Shivganga river basin, Pune, Maharashtra, India.

The present study is focused on seasonal variation in groundwater quality, hydrochemistry, and associated human health risk in the Shivganga river basin, Western Maharashtra, India, to promote sustainable development of groundwater resources of this semi-arid region. The qualitative geochemical analysis, contamination levels, and human health risk assessment (HHRA) of groundwater are integral steps in groundwater management in the Deccan Plateau basalt flow region of India. Representative groundwater samples (n = 68) collected from the Shivganga River basin area of Pune district, Maharashtra, during pre-monsoon (PRM) and post-monsoon (POM) seasons in 2015 were analyzed for major cations and anions. According to the World Health Organization (WHO, 2017) drinking standards, EC, total dissolved solids, hardness, bicarbonate, calcium, and magnesium surpassed the desirable limit. Boron and fluoride content exceeded the prescribed desirable limit of the WHO. The pollution and drinking suitability were assessed by computing pollution index of groundwater (PIG), groundwater quality index (GWQI), and HHRA particularly for boron and fluoride toxicity. PIG values inferred that about 6% of groundwater samples has moderate, 24% has low, and 70% has insignificant pollution in the PRM season, while only 1 sample (3%) showed high pollution, 6% showed low, and 91% showed insignificant pollution in the POM season. GWQI classification demonstrated that 27% and 15% samples are within the poor category, and only 15% and 18% of the samples fall into excellent water category in the PRM and the POM seasons, respectively. Total hazard index (THI) revealed that 88% of children, 59% of adults, and about 38% of infants are exposed to non-carcinogenic risk, as THI values (>1) were noted for the PRM season, while 62% of children, 47% of adults, and 24% of infants are vulnerable to non-carcinogenic health hazard during the POM period.

Hydrogeochemical Processes Governing Uranium Mobility: Inferences from the Anthropogenically Disturbed, Semi-arid Region of India.

Khetri Copper Belt, Rajasthan, is anthropogenically active and geologically belongs to the Delhi super-group. A study was designed to understand the geochemical processes controlling the elemental mobility in the groundwater. Sampling sites were divided into three zones, i.e. copper, quartzite and granite mine zones depending on the type of mineral excavated. A total of 32 representative groundwater samples were collected and analysed for heavy metals and radionuclide (U) using ICP-MS. A maximum U concentration (average 87 µgL-1) is observed in the quartzite mine zone, and minimum (average 13 µgL-1) is found in the copper mine zone samples. A high concentration of U (maximum of 430 µgL-1) in groundwater is attributed to mineral dissolution due to geogenic and anthropogenic activities. Despite the presence of Jaspura and Gothra granitoid in the copper mine zone, the abundance of U is low suggesting the scavenging of U by sulphides or iron oxides. Additionally, at the confluence of two geological groups, Fe concentration is found high with a low concentration of U which further confirms scavenging of U. It is evident from the results that in the absence of iron-bearing sulphides, U concentration in groundwater would be very high compared to the current concentration. It also indicates low concentration of U in the copper mine zone is due to dissolution of Fe sulphide-rich waste. The present study recommends further research to understand the feasibility of mining waste for the removal of U contamination from groundwater.

Evaluation of groundwater suitability for the domestic and irrigation purposes in Konaro Ophiolitic Area, Iranshahr, SE Iran

Hydrogeochemical characteristics of groundwater and its suitability for domestic and irrigation, purposes were evaluated in Konaro ophiolitic area. Heavy metals pollution is accounted for a major pollution in the natural environment are that can pose a serious threat to ecosystems because of their biodegradation potential, toxicity and sustainability (Moslempour and Shahdadi 2013) 8 representative groundwater samples were collected from wells and qanat and analyzed for major cations and anions. The order of dominance of cation and anions were Na> HCO3> SO4 > Mg> Cl> Ca> K, respectively. The rock weathering and dissolution of minerals processes, especially ophiolitic rocks minerals are dominant in controlling the groundwater quality in the study area. Electrical conductivity (EC) and total dissolved solid (TDS) show high positive correlation with total Hardness (TH), K, Na, and SO4-. As per the WHO standards for domestic water purposes, majority of samples show that the groundwater is suitable for drinking. The spatial distribution maps of physicochemical parameters were prepared in ArcGIS. The suitability of groundwater for agriculture purpose was evaluated from EC, TDS, sodium adsorption ratio (SAR) and Na% which ranges from excellent to not suitable, so majority of the groundwater samples are suitable for irrigation. The results revealed that the GQI quality index varied between 89% and 91% in the Konaro area, which in terms of quality rating, the water samples from these resources laid in appropriate to acceptable range. Moreover, based on examining the zoning map, the GQI quality index accounted for the lowest value in the east direction of the study area. Thus, most of the groundwater samples from this study (sample W2) confirm the beneficial use of aquifers in the area for domestic, agricultural, and irrigation purposes.

Spatial variability and hydrogeochemical characterisation of groundwaters in Larkana of Sindh, Pakistan

The current study examined the groundwater quality of different sampling stations of Larkana taluka based on GIS map using the interpolation method (IDW). The IDW method was applied in ArcGIS 10.5 software. Thirty representative groundwater samples were collected, mostly used for drinking purposes and examined for 24 different parameters. The water quality index (WQI) showed that 20.0% of samples were of poor water quality. The groundwater chemistry estimated from scatter diagrams showed weathering processes occurred in the study area. The silicate, carbonate, gypsum, farward ion exchange and reverse ion exchange were major weathering processes dominated in aquifer of study area. The land use may also be affecting groundwater chemistry. The samples were examined for coefficient of correlation (r), piper hydrochemical faces, Gibbs diagram, Chadha diagram and principal components analysis. EC, TDS, Cl, TH, alkalinity, Na, SO4, Ca, K and Mg were positively correlated to each other and indicated a similar geological origin. Total dissolved solids were observed 209–1642 mg/L and 76.71% samples were within permissible limit of 1000 mg/L. The results of nitrate, nitrite, orthophosphate, and total phosphate were within limits. The results of Pb 26.67%, Cr 16.67%, Cd 23.33%, and Ni 20.0% crossed the permissible limits of WHO for drinking purposes. The groundwater was examined for suitability for irrigation and 90–100% samples were indicated suitable for irrigation.

Seasonal assessment of groundwater contamination, health risk and chemometric investigation for a hard rock terrain of western India

Groundwater quality in the Shivganga river basin, Western India, was evaluated by an integrated approach using pollution index of groundwater (PIG), health risk assessment (HRA) and chemometric analysis. Sixty eight (68) representative groundwater samples were collected and analysed for pH, Electrical conductivity (EC), Total dissolved solids (TDS), major cation and anion during pre- (PRM) and post (POM)-monsoon seasons of 2016. Hydro-chemical analysis inferred that EC, total hardiness, alkalinity, boron and fluoride are exceeding the permissible limits of the World Health Organisation (WHO). PIG was computed based on considered physicochemical parameters and WHO drinking standards to ascertain the degree of pollution level. PIG results inferred that about 6% samples fall in moderate, 12% in low and 82% in insignificant pollution in PRM season; while, 12% of sample fall within low, 88% insignificant pollution in POM season. HRA was carried to know the health impacts of boron and fluoride toxicity on infants, children and adults. HRA results suggest that children are more susceptible to non carcinogenic health risk than infants and adults. Chemometric analysis included correlation matrix (CM), principal component analysis (PCA) and cluster analysis (CA) to know the relationship between water quality variables and their collective influence on overall groundwater quality. CM and PCA suggested that, inputs of TDS, Mg, NO3, Na, Cl, and SO4 are elevated due to rainfall and anthropogenic activities. These techniques are useful to evaluate the influence of seasonal variation of natural or anthropogenic processes controlling the groundwater quality in the study region.

Seasonal variation in groundwater quality and beneficial use for drinking, irrigation, and industrial purposes from Deccan Basaltic Region, Western India.

Sustainable management of groundwater resources requires detailed basin-wide water assessments. Semi-urbanized areas surrounding metropolitan cities in the western part of India were assessed for their suitability for domestic, irrigation, and industrial purposes. These study areas reflect rapid urban growth with residential complexes, combined with agricultural, horticultural, and industrial uses. Therefore, 68 representative groundwater samples were collected during the pre-monsoon (PRM) and post-monsoon (POM) seasons of 2015 and analyzed for major ions. According to the World Health Organization (WHO) drinking standards, parameters like EC, TDS, TH, HCO3, Ca, and Mg were found to exceed the desirable maximum limits, and the B and F content exceeded the permissible limits. The drinking suitability was studied using the modified water quality index (MWQI). The irrigation suitability was assessed using indices such as sodium adsorption ratio (SAR), percent sodium (%Na), and permeability index (PI). The industrial suitability was evaluated based on Langelier saturation index (LSI), saturation index (SI), Ryznar stability index (RSI), etc. MWQI results corroborate that 52.94 and 70% samples fall in no pollution category, and 47% and 30% samples were identified to be in the moderate category of pollution in the PRM season and POM season, respectively. The spatial variation maps of LSI, SI, RSI, Puckorius scaling index (PSI) and Larson-Skold index (LaI) show that the majority of the samples in the PRM season have low to insignificant scaling and corrosive potentials as compared to POM samples. The study results provide reliable information for water reserve managers to prepare the sustainable and more accurate basin management plans.

Evaluation of chemical composition and appraisal of groundwater appropriateness for drinking and agricultural practice in rural areas near Rania city of Haryana state, India

Haryana being the green land of the nation is highly cultivated state with a huge consumption of agrochemicals. The present study area Rania is the agricultural dominated area where the economy mainly depends upon agriculture. The present work emphasizes on the evolution of the hydro chemistry of the groundwater. For this, 30 representative groundwater samples have been collected in the month of May 2017 and analyzed for a number of quality parameters. Based upon the results of the quality analysis, a number of parameters such as Kelly’s index (KI), Sodium absorption ratio (SAR), residual sodium carbonate (RSC) and magnesium ratio (MR) have been considered to evaluate the aptness of groundwater for irrigation. Chloro-alkaline indices and Gibb’s ratios were calculated to understand the hydrochemistry of groundwater. A comparison of the results of the quality analysis has been made with the WHO standards to check the fitness for consumption. Pearson’s correlation coefficient has been used to establish the connection among various parameters.