This research was carried out to delineate the spatial distribution of shallow groundwater quality in Yan’an City, an important cultural city on the Chinese Loess Plateau, and to estimate the healt...

Spatial groundwater quality and potential health risks due to nitrate ingestion through drinking water: A case study in Yan’an City on the Loess Plateau of northwest China

Groundwater is critical for the sustainable development of the Loess Plateau, while groundwater quality is generally poor in this area due to natural factors and anthropogenic pollution. This study was carried out to investigate the suitability of groundwater for domestic and agricultural purposes in Yan’an City on the Chinese Loess Plateau and to assess its implications to sustainable groundwater management on the plateau. The index levels were compared with the threshold values established by the national and the WHO drinking water guidelines, and the suitability of groundwater for irrigation purposes was assessed using multiple agricultural water quality indicators. An entropy-weighted Technique for Order Preference by Similarity to an Ideal Solution (entropy-weighted TOPSIS) was adopted for overall groundwater quality assessment. The results indicate that the study area is characterized by saline, hard, and slightly alkaline groundwater, mainly of the HCO3–Ca·Mg type, accompanied by some minor SO4·Cl–Ca·Mg type. The dissolution of carbonates and gypsum and the leaching of soluble salts are important natural processes influencing the groundwater ion chemistry. The parameters TH, TDS, and SO42− are major indices, while Fe, Mn, F−, and NH4+ are minor contaminants affecting groundwater quality. The overall groundwater quality is generally acceptable for irrigation, and most of the water is suitable for drinking. Rainwater harvesting, water quality improvement programs, regular water quality monitoring, and multidisciplinary water research programs are suggested as measures for sustainable groundwater management on the Loess Plateau.

Groundwater quality assessment for domestic and agricultural purposes in Yan’an City, northwest China: implications to sustainable groundwater quality management on the Loess Plateau

Irrigation with Saline Water

Groundwater quality in the alluvial plains of Punjab has special significance and needs great attention since it is the foremost source of drinking, irrigation and industrial uses. The present research work emphasizes the integrated hydrogeochemical and chemometric statistical approaches to appraise the geochemical processes and source apportionment of the groundwater in the alluvial plains of Jalandhar district, Punjab, India. The human health risk assessment was also performed to quantify the potential non-carcinogenic impacts of nitrate and fluoride on human health through ingestion of groundwater. For this purpose, 41 groundwater samples were collected from different groundwater abstraction units and analysed for pH, electrical conductivity, total dissolved solids, total hardness, total alkalinity and major ions (Ca2+, Mg2+, Na+, K+, HCO3−, CO32−, SO42−, NO3−, F−, Cl− and PO43−) using standard protocols. Drinking water quality index and Revelle index showed that groundwater samples fall under poor to unfit water class and salinization along the south-western portion of the study region shows poor water quality. The results of the hazard index (HIingestion) show 68% and 46.34% of the groundwater samples have HI > 1 for children and adults. The non-carcinogenic health risk assessment of nitrate (NO3−) and fluoride (F−) on the local population indicated that the children are more vulnerable through direct ingestion of drinking water than adults. Piper diagram and saturation index reveal that Ca2+–Mg2+–HCO3− is the dominant hydrochemical facies and oversaturated with calcite, dolomite and aragonite minerals in the groundwater. Gibbs diagrams, chloro-alkaline indices and scatter plots show that the hydrochemistry of the groundwater is mainly governed by aquifer material interaction such as weathering of silicate, carbonate rock, halite dissolution and cation exchange process. Chemometric statistical techniques revealed that the source identification of parameters such as Ca2+, Mg2+, Na+, K+, HCO3−, CO3− and F− is originated from geogenic factors, whereas NO3−, SO42−, Cl− and PO43− are from the anthropogenic origin. Therefore, urgent and efficient measures must be taken to combat groundwater pollution and reduce human health risk in the study area.

Evaluation of groundwater quality and human health risks from fluoride and nitrate in semi-arid region of northern India

The main objective of the present research was to examine the risk of fluoride-rich groundwater in the Shanmuganadhi River basin, south India on human health. The non-carcinogenic risks were estimated into two classes: (1) risks associated with oral intake of water and (2) risks associated with dermal contact. Hazard Quotient for oral intake and dermal contact was separately calculated for adult men, adult women and children from the geochemical results of 61 representative samples collected from the wells constructed in hard rock aquifers during the post- (January-2018) and pre-monsoon (May-2018) seasons. The collected samples were analyzed immediately after the field work for all the major ions and fluoride. Finally, total hazard index was calculated for adults (men and women) and children to evaluate the risk. It directed that 41%, 49% and 74% of post-monsoon samples and 30%, 43% and 62% of pre-monsoon samples possessed a non-carcinogenic risk for men, women and children, respectively. Because the basin falls in the drought-prone region, the water supply for drinking and cultivation are commonly based on groundwater resources. The study revealed that the minerals such as apatite, fluorite, biotite and pyroxene in the hornblende–biotite gneiss formation contribute fluoride ions to the groundwater system due to water–rock interaction mechanism. The Durov diagram depicted that dissolution of silicate minerals and cation exchange are the foremost hydrogeochemical activities, which decide the overall chemical composition of groundwater in this region. The ionic concentrations including fluoride increased with respect to depth of occurrence of groundwater. Escalation of the water table due to monsoon recharge and artificial recharge through a check dam decreased the total dissolved solids and fluoride ion concentration. The investigation conducted around the existing check dam at Kaldurai village highlighted that the fluoride concentration is below the allowable limit of 1.5 mg/l (WHO in World health statistics 2017: monitoring health for the SDGs, Sustainable Development Goals. World Health Organization, Geneva, 2017) in the wells closer to the check dam toward the downstream side. The concentration increased with distance, which lead the groundwater unsuitable for consumption. Therefore, it is recommended to implement the managed aquifer recharge using check dams in the other parts of the basin to enrich the quantity and applicability of groundwater.

Risk of Fluoride-Rich Groundwater on Human Health: Remediation Through Managed Aquifer Recharge in a Hard Rock Terrain, South India

The present work was carried out in Nalbari district of Assam (India) with an objective to assess the quality of groundwater and to check its suitability for drinking and irrigation purposes. Groundwater samples were collected from 50 different locations during pre- and post-monsoon seasons of 2016. Results of chemical analysis revealed that mean concentration of cations varied in the order Ca2+ > Na+ > Mg2+ > K+, while for anions the order was HCO3 − > Cl− > SO42− > NO32− > F− during both pre- and post-monsoon seasons. The suitability of groundwater samples for drinking purpose was assessed by comparing the results of physico-chemical analysis of groundwater with Indian Standards. Further, its suitability for irrigation purpose was assessed by evaluating several parameters like sodium adsorption ratio (SAR), sodium percentage (Na%), magnesium ratio, Kelly’s ratio and residual sodium carbonate (RSC). The SAR values obtained for all the samples were plotted against EC values in the US Salinity Laboratory diagram, and it was revealed that the most of the samples fall under water type C2-S1 indicating medium salinity and low SAR. Further, it was found that the majority of the samples belong to Ca–Mg–HCO3 hydrochemical facies followed by Ca–Mg–Cl–SO4, whereas only a few samples belong to Na–K–HCO3 hydrochemical facies.

Assessment of groundwater quality for drinking and irrigation purposes using hydrochemical studies in Nalbari district of Assam, India

Present research aims to assess the suitability of groundwater of Dera Bassi town (Punjab) and its surrounding agricultural area for drinking as well as irrigation purpose. Thirty groundwater samples were collected (in February 2020) and analyzed for various physicochemical parameters. Results of physicochemical analysis were compared with Indian (IS 10500:2012) as well as WHO (2006) standards to ascertain the suitability of the groundwater samples for drinking purpose, and it has been found that results for almost all the parameters except alkalinity (at few sites) are within the permissible limit. The pattern of ionic dominance was observed in the order of Ca2+ > Mg2+ > Na+ > K+ for cations and Cl− > NO3− > SO42− > F− for anions. Further, according to the observed Kelly’s ratio, sodium adsorption ratio, sodium percentage, corrosivity ratio and permeability index, the groundwater samples were found to be fit for irrigation purpose. However, the magnesium ratio and residual sodium carbonate revealed that groundwater of the area under study is not fit for irrigation purpose at some sites. The plot of SAR values versus EC values in the US Salinity Laboratory diagram revealed that the majority of the samples fall under water type C3-S1 (high salinity—low SAR) and 36.77% samples fall under water type C2-S1 (medium salinity—low SAR). Gibb’s diagram revealed that all samples fall under rock dominance category. The values of index of base exchange (CAI 1 and CAI 2) indicate that both direct ion and reverse ion exchange processes are taking place in the region.

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Assessment of groundwater quality for drinking and irrigation purpose using hydrochemical studies in Dera Bassi town and its surrounding agricultural area of Dera Bassi Tehsil of Punjab, India

The assessment of potentially toxic elements’ contamination in surface soils of Kulsi River Basin in North East India has been studied based on the analysis of 50 soil samples collected from the basin. The average concentrations of Co (2.30 mg/kg), Ni (7.26 mg/kg), Pb (9.41 mg/kg), and Zn (22.7 mg/kg) surpassed the background levels prescribed for sedimentary rocks which indicated anthropogenic contribution of these metals. The average values of enrichment factors for different elements under study followed the order as Co > Ni > Zn > Pb > As > Fe > Cr. Results of multi-element indices revealed significant contamination at many sites; however, computed values for potential ecological risk index indicated only low ecological risk at all the sampling sites. The contribution of individual toxic elements toward the potential ecological risk followed the order as Co > Ni > As > Pb > Zn > Cr. The study recommends that suitable measures need to be taken for checking any further contamination in the area.

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Upma Vaid

Papers

Assessment of groundwater quality for drinking and irrigation purposes using hydrochemical studies in Nalbari district of Assam, India

Assessment of groundwater quality for drinking and irrigation purpose using hydrochemical studies in Dera Bassi town and its surrounding agricultural area of Dera Bassi Tehsil of Punjab, India

Assessment of potentially toxic elements’ contamination in surface soils of Kulsi River Basin in North East India