An increased nitrate (NO
) concentration in groundwater has been a rising issue on a global scale in recent years. Different consumption mechanisms clearly illustrate the adverse effects on human ...health. The goal of this present study is to assess the natural and anthropogenic NO
concentrations in groundwater in a semi arid area of Rajasthan and its related risks to human health in the different groups of ages such as children, males, and females. We have found that most of the samples (n = 90) were influenced by anthropogenic activities. The background level of NO
had been estimated as 7.2 mg/L using a probabilistic approach. About 93% of nitrate samples exceeded the background limit, while 28% of the samples were beyond the permissible limit of 45 mg/L as per the BIS limits. The results show that the oral exposure of nitrate was very high as compare to dermal contact. With regard to the non-carcinogenic health risk, the total Hazard Index (HI
) values of groundwater nitrate were an average of 0.895 for males, 1.058 for females, and 1.214 for children. The nitrate health risk assessment shows that about 38%, 46%, and 49% of the samples constitute the non-carcinogenic health risk to males, females, and children, respectively. Children were found to be more prone to health risks due to the potential exposure to groundwater nitrate.
Arsenic contaminated groundwater is seen as one of the most critical routes of human exposure to geogenic pollutants. Recently around 40 million inhabitants of the world are living in the hazardous ...zone having groundwater As level >50 μg/L. As problem of groundwater in Bhagirathi–Ganga deltaic plain is well-known for over the last three decades. Hydrogeochemical analytical data related to the As concentration had been analysed to identify the As sources in groundwater of the active floodplains of the Ganga basin in Northern India. The natural background level of As was also estimated using Grubb’s test and cumulative probability plots. The natural background level is a crucial parameter for identifying and quantifying groundwater pollution and assessing measures to control pollution. The anthropogenic addition of As in groundwater was separated by the estimated inflection point. The results show that the highest As concentration, which is 8-times more than the permissible limit, is observed at Gyantoli village in Begusarai district in Bihar state. Groundwater is alkaline with a high concentration of HCO3− as compared to other chemical parameters. Further, it indicates the dominance of carbonate weathering and relatively high pH values (range: 8.00–9.00) helps to release As in groundwater. The reducing environment of the aquifer system becomes oxic at the shallow depth due to comparatively shallow groundwater level, and impressive water level fluctuation resulting in vertical mixing of anthropogenic As contaminants.
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•Natural Background Level (NBL) of Arsenic (As) in groundwater is estimated.•The NBL of As is influenced by both geogenic and anthropogenic processes.•HCO3− and pH supported As leaching in groundwater in floodplains of Ganga basin.•Shallow water level influences the oxic environment enhance the As-contamination.
Assessment of morphodynamic groundwater reserves is important for the sustainable management of water resources. It is a truth that groundwater resource evaluation is anxious with the ambiguity of ...its several factors and employing methods. Thus, an information-based model has been hypothesized to assess natural groundwater reserves in a morphodynamic system in a part of the Ganga basin of Northern India, where the spatial variability in natural groundwater reserve exists. Marginal information of rainfall data, and transinformation among the rainfall, and monthly depth to groundwater level measurement at 50 wells in a dense monitoring network were used for evaluating natural groundwater reserve. The results indicate that an average recharge rate is about 246 mm/monsoon and or 32.65% of the seasonal rainfall, and its values are well-correlated with the soil infiltration rate. It has been found that the estimated recharge rates are about 54.08, 45.85, 33.77, 32.48, and 32.14% of the seasonal rainfall in an active flood plain, back swamp, natural levees, flood plain, and palaeochannel, respectively. The calculated annual rainfall input to groundwater reserve is found about 127.98 MCM/monsoon rainfall, which could be employed for sustainable management of groundwater resources in the morphodynamic system of the Ganga river basin.
Dense data acquisition for 3-D high-resolution aquifer mapping through heliborne transient electromagnetic (HTEM) survey is continually not possible due to various technical and administrative ...constraints. Consequently, we apply ground geophysical surveys at possibly closer spacing to collect the sub-surface information in the no-fly area, which provides only a regional aquifer picture. In the area near Patna of Northern India, an extent of 18% was covered under the HTEM survey, and the rest was surveyed by ground geophysical methods. Both data are integrated using the theory of regionalized variables. The parameters of multi-aquifers i.e., top of the first aquifer, top of the separating clay layer, top and the bottom of second aquifer, are estimated together with their respective resistivities. The estimations are made at an interval of 250 m, practically an appropriate distance at which dense data generation was carried out using the HTEM survey. The integrated approach generates the data in the no-fly area with the same spatial density as the flown area. With this, we achieved the goal of completing the 3-D aquifer mapping of the entire area with dense data at high spatial resolution. This is a unique finding to manage the handicapped situation in this HTEM surveys, and an aide to overcome such constraints with cost-effectiveness.
Natural background levels (NBLs) and threshold values (TVs) are crucial parameters for identification and the quantification of groundwater pollution, and the evaluation of pollution control ...measures. The cumulative probability distribution technique was used for the evaluation of NBLs for 36 samples collected during two climate conditions in the part of the desert area from Rajasthan, India. The NBLs for Na+, Cl−, SO42−, HCO3−, NO3− and F− ions were assessed and compared with the natural and anthropogenic processes. The TVs were also calculated for Na+, Cl−, SO42−, HCO3−, NO3− and F− ions, and compared with the drinking limits of the Bureau of Indian Standards. Additionally, the pollution percentage (%) at the individual well was estimated and identified the polluted zones. Results indicate that most of the polluted areas were situated in the southern part, which was influenced by the natural and anthropogenic factors. The sodium concentrations above the TVs, in indicating the saline nature of water. Chloride threshold value above the drinking water limit was mainly observed in the dry season, related to intensive evaporation and industrial waste, which leads to groundwater quality degradation. The NO3− concentration (∼56% samples) above the TVs indicates extensive use of nitrate fertilizers and sewage effluent. The values of total dissolved solids (TDS) shows the suspicious scenario as about 84% of the samples in the dry period and about 89% in the wet season exceeding the drinking limit. Assessment of background concentrations and threshold values on regional and local scale assigns the basis for the identification of groundwater pollution, and helpful for better water quality guidelines to protecting of water resources.
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•Cumulative probability plots have separated the natural background levels (NBLs).•Threshold values of hydrochemical parameters indicate the contamination.•Use of fertilizers and sewage effluent influence the NBLs of NO3− in groundwater.•Long-term dissolution of quaternary sediment and rocks causes high NBLs of HCO3−.•Evaporation of lowlands leads anomalous to salt concentration in groundwater.
This article deals with the remote sensing and geographic information system techniques in assessing groundwater potential zones by the manipulation and analysis of the individual layer of spatial ...controlling data in a part of Deccan Volcanic Province, Maharashtra. Available geology, geomorphology, and soil maps were collected. Land use and land cover (LULC) and Lineament maps had been prepared using the LANDSAT-8 (TM and OLI) Satellite Image (November 2015). The SRTM DEM (resolution: 30 m) data had been employed for the preparation of slope and drainage maps. These maps were converted into the raster format. Analytic hierarchy process was applied to weight, ranking, and reclassify these maps in the ArcGIS version 10.4. Then, groundwater prospect map had been prepared by overlaying the maps. The results show that five groundwater potential zones such as very poor (11.77%), poor (21.73%), moderate (30.13%), good (25.34%), and very good (11.02%) exit. Sensitivity analysis reveals that the lineament density, LULC, and slope increase the area slightly only in the very poor to poor potential zones. Besides, the well yields, groundwater level fluctuation corresponding rainfall data had been utilized to validate. The yield values vary from 5.94 to 14.88 l/s in the good to very good potential zones, whereas 0.38 to 1.37 l/s within the poor to very poor potential zones. In addition, cross-correlation coefficients among groundwater level and rainfall is well-related to the groundwater potential index (
R
2
= 0.84), which will help to construct artificial recharge structures and the planning of sustainable groundwater management.
In this article, the fabrication of anion exchange membranes from brominated poly(2,6-dimethyl-1,4-phenylene oxide) (BPPO) and N-methylmorpholine (NMM) has been reported. The prepared membranes were ...characterized in terms of ion exchange capacity (IEC), water uptake (WR), linear expansion ratio (LER), thermal stability, tensile strength (TS), alkaline stability, transport number and membrane area resistance. The ion exchange capacity, water uptake and linear expansion ratio of the prepared membranes are found to be increased with the increasing amount of NMM content in the membrane matrix. The membranes NMM-15 and NMM-18 are much more stable than QPPPO membrane in 2M NaOH at room temperature. Fourier transform infrared spectroscopy was employed to confirm the functional groups in the membrane. The surface morphology of fabricated membranes was studied by scanning electron microscopy. The membranes were used in electrodialytic removal of NaCl from aqueous solution at constant applied voltage. The membrane NMM-18 with higher hydrophilicity (IEC=1.74mmol/g & WR=27.40%) and lower membrane area resistance (1.5Ω·cm2) showed good ED performance than commercial membrane Neosepta AMX under the same experimental conditions.
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•Anion exchange membranes with N-methylmorpholine (NMM) groups were developed.•The membrane performance can be controlled by NMM contents.•The membranes possess excellent stability as well as high ED performance.
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