Magnesium Adsorption Research Articles

Impact of landuse on groundwater quality of Bangladesh

Groundwater pollution is a major concern in water resources management across the world. The objective of this study is to characterize groundwater quality and identify the impact of landuse on groundwater quality of Bangladesh. Total of 113 groundwater samples, collected from shallow aquifers at different locations of Bangladesh were analysed to estimate eight standard groundwater quality indices namely, sodium absorption ratio (SAR), soluble sodium percentage (SSP), residual sodium bi-carbonate (RSBC), permeability index (PI), total hardness (TH), magnesium adsorption ratio (MAR), Kelly’s ratio (KR) and total dissolved solids (TDS). The results showed that the SAR in groundwater of Bangladesh varies between 1 and 818, SSP between 9 and 99%, RSBC between − 13 and 719 meq/L, PI between 21 and 112%, TH between 233 and 19400 meq/L, MAR between 5 and 74%, KR between 0.06 and 135 meq/L, and TDS in the range of 51–15200 mg/L. Significant differences in groundwater quality indices between agricultural and forest lands were observed. The study revealed that higher amount of total dissolved salt in groundwater was due to sea water intrusion into the coastal aquifer. Relation between agriculture and groundwater quality suggests that though the nitrate concentration in groundwater was less than permissible level, it might increase in future due to extensive use of nitrogen-based chemical fertilizers in agriculture.

Evaluation of Groundwater Suitability for consumption in Yaychi area (Southwest Kirkuk city - North Iraq)

Groundwater suitability for consumption in the Yaychi area is determined by analyzing groundwater samples of 21 wells distributed in the area, for dry period which begin from May to October 2016 and wet period begin from October 2016 to May 2017. Results indicated that the temperature (T °C) have normal values and the water of low alkaline and excessively mineralized, while most of these samples, for both periods, are slightly – brackish water. The mean ion concentrations for two periods indicates that all major and secondary ions are higher than water quality standards for drinking purposes according to World Health Organization (WQI) and Iraqi Standard (IQS) except for K and Cl ions. The water in the study area is classified as very hard. Kurolov formula shows the presence of three predominant salts MgSO4, Na2SO4 and CaSO4, and the water origin in the area is meteoric water. The predominated of water types are earth alkaline water with increased portions of alkalis with prevailing sulfate and chloride and Normal earth alkaline water with prevailing sulphate or chloride. After comparing the ionic concentrations with the water quality standards for different purposes, it was found that groundwater in the area is unsuitable for human drinking, but it's suitable for building and livestock and for growing most types of crops, it is also suitable for irrigation purposes depending on the sodium adsorption ratio (SAR), Soluble Sodium Percentage(Na%) and the Residual Sodium Carbonate (RSC), and unfit for irrigation according to Magnesium Adsorption Ratio(MAR) index. The water in the study area is devoid of heavy metal pollution except (Fe), (Pb) which are shown in water of some wells.

Geochemical assessment of water quality for irrigation in abandoned limestone quarry pit at Nkalagu area, southern Benue Trough, Nigeria

In the study, the quality of groundwater for irrigation is assessed. The following parameters were analysed using American Public Health Association standard method: pH, turbidity, electrical conductivity, total dissolved solids, Mg2+, SO42−, Cl−, HCO32−, K+, Na2+ and Ca2+. Important constituents that influence the water quality for irrigation are electrical conductivity which ranges from 4 to 1560 µS/cm, soluble sodium percentage which ranges from 4 to 33%, magnesium adsorption ratio (MAR) which ranges from 30 to 81, Kelly’s ratio which ranges from 0 to 0.5, sodium percentage (Na %) which ranges from 4 to 50%, sodium adsorption ratio which ranges from 0 to 0.6, residual sodium carbonate (RSC) which ranges from 1.5 to 3.5, permeability index which ranges from 157 to 675% and total hardness (TH) which ranges from 102 to 614 mg/L in Nkalagu water. The above estimated parameter values satisfy the various permissible standard values for irrigation except MAR, TH, RSC that are slightly above the various permissible standard values. The hydrogeochemical facies analysis plotted in Piper diagram reveals that 53.85% of the samples are predominantly (Cl−–SO42−) facies, 15.38% are (SO42−–Cl− and SO42−–Cl−–HCO3−) facies, while 7.69% are (Mg2+–SO42−–Cl−–HCO3− and Cl−–SO42−–HCO3−) facies. The water type is Ca–Cl2 with much considerable permanent hardness. Although some samples satisfied the various permissible standard values for irrigation, treatment is, however, very strongly recommended to improve the quality and make it more suitable for irrigation.

Groundwater Monitoring in the Gneisso-Basaltic Fractured Rock Aquiferous Formations of Kumba, Southwest Region Cameroon: Seasonal Variations in the Aqueous Geochemistry and Water Quality

The objective was to determine and monitor seasonal changes during four hydrological seasons: Wet season (September), Wetdry season (December), Dry season (March) and Drywet season (June) in the groundwater aqueous geochemistry and its domestic-agro-industrial quality using physicochemical parameters and hydrogeochemical tools: Temperature, Electrical Conductivity EC, pH, Total dissolved solids TDS, Ionic ratios, Gibbs diagrams, Piper diagrams Durov diagrams, total hardness HT, Water quality index WQI, Sodium adsorption ratio SAR, Percent Sodium %Na, Kelly’s Ratio KR, permeability index PI, Magnesium adsorption ratio MAR, Residual sodium carbonate RSC and Wilcox diagram. Field physicochemical parameters ranged from: Wet season; pH 3.9 - 6.9; Temperature, 23.3°C - 29.1°C; EC, 10 - 1900 μS/cm; TDS, 6.7 - 1273 mg/L; Wetdry, pH, 5.7 - 11.7; Temperature, 23.6°C - 28.3°C; EC, 1 - 1099 μS/cm, TDS, 0.67 - 736.33 mg/L; Dry pH, 5.7 - 13.1; Temperature, 26.3°C - 30.2°C; EC, 12 - 770 μS/cm, TDS, 8.04 - 515.9 mg/L and Drywet, pH, 4 - 7.4; Temperature, 25.8°C - 30.7°C; EC, 10 - 1220 μS/cm, TDS, 6.7 - 817.4 mg/L. Seventy-two groundwater samples, 18 per season were analysed. All ionic concentrations fell below acceptable World Health Organization guidelines in all seasons. The sequence of abundance of major ions are; Wet, Ca+ > Mg2+ > Na+ = K+ > NH4+, HCO3? > Cl? > NO3? > SO42? > HPO42?; Wetdry Ca+ > K+ > Mg2+ > Na+ > NH4+, HCO3? > Cl? > SO42? > NO3? > HPO42?; Dry Ca+ > K+ > Mg2+ > Na+ > NH4+, HCO3? > Cl?> NO3? > SO42? > HPO42?; Drywet NH4+ > Ca+ > K+ > Mg2+ > Na+; Cl? > HCO3? > NO3? > SO42? > HPO42?. Groundwater ionic content was due to rock weathering and ion exchange reactions. CaSO4 is the dominant water type in Wet and Wetdry seasons; followed by CaHCO3, Na + K-Cl Wet, CaSO4 and CaHCO3 Wetdry; MgCl Dry and Drywet followed by CaCl, CaHCO3 Dry and CaSO4, CaHCO3 Dry-Wet. The dominant hydrogeochemical facies are Ca-Mg-Cl-SO4 followed by Na-K-SO4 Wet and Ca-Mg-HCO3? in all other seasons. Ion exchange, Simple dissolution and uncommon dissolution are the processes determining groundwater character. The water quality indices; WQI, HT, SAR, %Na, KR, PI, MAR,RSC and Wilcox diagrams, indicate that groundwater in Kumba is 80% - 100% excellent during the Drywet &Wet seasons, 5% - 10% unsuitable during the Wetdry & Dry seasons for domestic use while being excellent-good for Agro-Industrial uses in all other seasons. Physicochemical parameters in some areas exceeded permissible limits for drinking. All hydrogeochemical parameters vary with seasons and these variations show the impact of annual cycles of seasonal changes on the aqueous geochemistry of groundwater in Kumba.

Hydrochemistry and water quality assessment of the Maroon River in Behbahan area, SW Iran

Abstract Assessing water quality is important in optimizing water usage. In this study, six water samples were taken from points along the Maroon River in order to evaluate its quality. The concentrations of Cl−, SO42−, HCO3−, CO32−, NO3−, K+, Mg2+, Na+, and Ca2+, as well as pH, electrical conductivity (EC) and total dissolved solids (TDS) were measured. The results were compared with the WHO (World Health Organization) drinking water guidelines and the FAO (Food and Agricultural Organization of United Nations) standard for irrigation water. The values of EC, TDS, Ca2+, Cl− and SO42− in two samples, and that of Mg2+ in one sample from downstream exceed WHO recommended limits. The K+, Na+ and NO3− concentrations are below the WHO limits. The dominant water facies is bicarbonate-calcium (HCO3-Ca). A Schoeller diagram shows that the water samples are of ‘Good’ and ‘Intermediate’ classes, while a Wilcox diagram reveals that the water is in classes C2S1, C3S3 and C3S2 – i.e., ‘Good’ or ‘Intermediate’ – for agricultural purposes. The water quality indices %Na, sodium adsorption ratio (SAR), residual sodium carbonate (RSC), permeability index (PI), magnesium adsorption ratio (MAR) and Kelly's ratio (KR), also indicate that the water is suitable for irrigation. In terms of EC, the water samples are of ‘Good’ and ‘Permissible’ quality. Geochemical investigations show that the water chemistry is influenced by evaporation, dissolution of evaporitic minerals, ion exchange and human activities.

Analysis of water quality of selected irrigation water sources in northern Ghana

Abstract Small-scale irrigation continues to cushion the food security gap in sub-Saharan Africa. Irrigation is largely governed by water availability, soil type and crop water requirements, among other factors. Thus, a study was conducted to assess the suitability of various water sources for irrigation in northern Ghana. Specifically, the study sought to assess quality of water sources in the Savelugu, Kasena-Nankana East, and Nabdam districts for small-scale irrigation development. The water quality parameters used were: pH, electrical conductivity (ECw), sodium adsorption ratio (SAR), sodium percent (Na%), soluble sodium percentage (SSP), magnesium adsorption ratio (MAR), Kelley's ratio (KR), total hardness (TH), chloride (Cl), Escherichia coli, and fecal coliforms. While we found most of the irrigation water sources, including small reservoirs, dams, wells and rivers suitable, few unsuitable irrigation water sources were also identified. Overall, the study found that opportunities for scaling small-scale irrigation exist in all the sites. The knowledge generated from this study will guide irrigation water use, and agricultural policy for sustainable smallholder irrigation development in the region.

Evaluation of Water Quality for Sustainable Agriculture in Bangladesh

Sustainable groundwater quality has become a major concern for the agro-based country like Bangladesh. Integrated approaches of various irrigation water quality indices and geostatistical modeling were applied to evaluate the suitability and for spatial mapping of groundwater quality of Faridpur District in central Bangladesh. The irrigation water quality index (IWQI) revealed that majority of the samples were suitable for irrigation. Similar outcomes were recorded from other indices including Na%, sodium adsorption ratio (SAR), residual sodium bicarbonate (RSBC), total hardness (TH), Kelley’s ratio (KR), and magnesium adsorption ratio (MAR). Classifications based on Wilcox diagram and permeability index (PI) plot indicated a similar conclusion wherein almost all the samples were safe for agricultural uses without posing considerable effect on the soil fertility and overall crop yield. Principal component analysis (PCA) grouped the major cations and anions into three principal components including dissolution of calcite minerals, leaching of silicate sediments, and ion exchange process. Spatial mapping of IWQI identified that groundwater in the northern side of Faridpur region were more suitable for irrigational uses relative to central and southern side, possibly due to gradients of domestic discharges and agricultural activates from north to south side. These findings would provide useful information to water distributors, managers, and decision makers for taking adaptive measures in irrigation water quality management systems.

English

Groundwater contamination is gaining more concerns due to its direct and/or indirect impact on public health. Groundwaters from various sources are commonly used to irrigate vegetables in Maiduguri, Borno State. In this study, the physicochemical qualities of groundwater collected from 20 randomly selected tube wells in Maiduguri were evaluated for their suitability or otherwise for irrigation purposes. Selected wells were extensively used as sources of irrigation water. Standard procedures were followed during the analysis. The results revealed that the mean values of  pH (6.6 to 8.0), calcium (2.6 to 5.2 meq/l), magnesium (2.6 to 5.0 meq/l), sodium (2.2 to 7.5 meq/l), carbonate (0.5 to 1.3 meq/l) , bicarbonate (1.8 to 5.2 meq/l), chloride ( 0.9 to 2.9 meq/l), sulphate (2.8 to 9.8 meq/l), potassium (0.3 to 0.9 mg/l), Boron (0.1 to 0.6 meq/l)  and nitrogen (1.9 to 4.8 mg/l) were all found to be within the acceptable limit for suitability of water for irrigation use based on Food and Agriculture Organization (FAO) recommendations. The results further revealed that, the values of electrical conductivity (0.3 to 0.7 ds/m), total dissolved solids (192 to 448 mg/l), sodium adsorption ratio (0.40 to 3.62), residual sodium carbonate (-1.3 to -7.6 meq/l), magnesium adsorption ratio (35.80 to 49.06%) and Kelly ratio (0.10 to 0.90) of the samples were within the safe limit recommended for irrigation water use. The quality of tube well waters in the study area can thus be regarded as good, and suitable for irrigation purposes, but similar analysis should be conducted on a routine basis to monitor the qualities of the waters toward safeguarding public health. Key words: Tube well waters, physicochemical qualities, irrigation suitability, public health, Maiduguri.

A study of groundwater irrigation water quality in south-central Bangladesh: a geo-statistical model approach using GIS and multivariate statistics

Southern Bangladesh’s irrigation and drinking water is threatened by saline intrusion. This study aimed to establish an irrigation water quality index (IWQI) using a geostatistical model and multivariate indices in Gopalganj district, south-central Bangladesh. Groundwater samples were taken randomly (different depths) in two seasons (wet-monsoon and dry-monsoon). Hydrochemical analysis revealed groundwater in this area was neutral to slightly alkaline and dominating cations were Na+, Mg2+, and Ca2+ along with major anions Cl− and HCO3 −. Principal component analysis and Gibbs plot helped explain possible geochemical processes in the aquifer. The irrigation water evaluation indices showed: electrical conductivity (EC) >750 µS/cm, moderate to extreme saline; sodium adsorption ratio (SAR), excellent to doubtful; total hardness (TH), moderate to very hard; residual sodium bicarbonate, safe to marginal; Kelly’s ratio >1; soluble sodium percentage (SSP), fair to poor; magnesium adsorption ratio, harmful for soil; and IWQI, moderate to suitable. In addition, the best fitted semivariogram for IWQI, EC, SAR, SSP, and TH confirmed that most parameters had strong spatial dependence and others had moderate to weak spatial dependence. This variation might be due to the different origin/sources of major contributing ions along with the influence of variable river flow and small anthropogenic contributions. Furthermore, the spatial distribution maps for IWQI, EC, SSP, and TH during both seasons confirmed the influence of salinity from the sea; low-flow in the major river system was the driving factor of overall groundwater quality in the study area. These findings may contribute to management of irrigation and/or drinking water in regions with similar groundwater problems.

An evaluation of irrigation water suitability in the Dwarka river basin through the use of GIS-based modelling

A GIS-based irrigation water quality (IWQ) assessment of the Dwarka river basin was undertaken using water suitability indicators including determinations of values of: soluble sodium percentage, exchangeable sodium ratio or Kelly ratio, residual sodium carbonate, magnesium adsorption ratios, total hardness, sodium adsorption ratio and permeability indices, electrical conductivity, and fluoride concentrations (F−). Inverse distance weighted algorithms and weighted overlays were used to categorise irrigation water quality into a number of zones. The IWQ zonation analysis revealed that about 10% (42.15 km2) of the total area had water quality unsuitable for irrigation thereby potentially exposing a population of 35744 people from 110 villages to health risks, whereas the remaining 91.31% (393 km2) of the study area is considered to have suitable irrigation water. The villages of Nawapara, Sehara and Deucha have been particularly affected by poor water quality, potentially exposing 294 (100%), 114 (97%) and 1556 (87.76%) of the total village population, respectively, to health effects. Combined efforts of government agencies and NGOs in educating the local communities regarding artificial groundwater recharge, rainwater harvesting, watershed management can play a crucial role in the long run in minimising the potential impacts of poor water quality in these areas.

Quality indices of groundwater for agricultural use in the Soconusco, Chiapas, Mexico

In Soconusco, Chiapas, in spite of the high availability of surface water, it is resorting to the use of groundwater. Knowledge about the quality of surface or groundwater used to irrigate crops in that region is low. This paper aims to contribute to the knowledge of the quality of groundwater for agricultural use through the characterization of the spatial variability. Assuming a random spatial distribution of 45 samples which were collected in situ were determined: acidity and alkalinity (pH), electrical conductivity (EC), Total Dissolved Solids (TDS), cations and anions and trace elements; in addition to the agricultural index: Sodium Adsorption Ratio (SAR), Residual Sodium Carbonate (RSC), Soluble Sodium Percentage (SSP), Sodium Percentage (% Na), Kelly Ratio (KR), Magnesium Adsorption Ratio (MAR), Permeability Index (PI), Effective Salinity (ES), Salinity Potential (SP) and Osmotic Potential (OP). In general, SSP, % Na, KR, PI are low, there is only one anomalous point (9) with high values at W of the study area. Similarly, PS, ES, Cl, Na and SAR are low except point 16 and conversely, RSC and pH are high, except at this point located in the center of the study area. The results allow us to infer that the water in that aquifer presents no problems or sodicity toxic ions. In 27 sites sampled values above 250 µmhos/cm were found at 25°C, classified as medium to high risk of salinity, unsuitable for agricultural use. Analysis of the combined effect of the presence of sodium (SAR) and salinity (EC or TDS) shows that 27 of analyzing sites have restricted water medium at very high for use in irrigation.

ASSESSMENT OF WASTEWATER FOR DISPOSAL IN ACCORDANCE WITH NEQS CRITERIA AND ITS REUSE FOR IRRIGATION WITH DILUTION

According to Section 11 of Pakistan Environmental Protection Act (PEPA) 1997, “No person shall discharge or emit or allow the discharge of any effluent or waste in an amount, concentration or level which is more than the National Environmental Quality Standards(NEQS)”. Even in the presence of this act there are many housing societies and Industrial zones, which are continuously disposing off their untreated wastewater to the natural water bodies. In this study Laboratory investigations on 5 composite samples were carried out. Total of 19 parameters were analyzed including Total Dissolve Solid (TDS), Total Suspended Solids (TSS), Bio-Chemical Oxygen Demand (BOD), Chemical Oxygen demand (COD), Sulfide, Fluoride, Lead, Nickel, Boron, Copper, Iron, Zinc, Manganese, Chlorine Total and Chromium hexavalent with average value of 502.6, 665.6, 267.4, 453.8, 3.1,5.3 0.6, 0.4, 1.4, 0.5, 0.5, 2.15, 0.6 and 0.5 mg/L respectively. TSS, BOD, COD and Mn exceeded the limits of NEQS for all samples.The same wastewater can be used for irrigation purpose if it fulfills FAO irrigation water criteria. For this purpose, important properties like SAR, Sodium ratio, Salt Index, Residual Sodium Carbonate, Permeability Index, Magnesium Adsorption Ratio, Sulfate ion and Boron were analyzed having result of 9.36 √(meq/L), 5.64, 75 ppm, 4.66 meq/L, 110.46, 0.42, 6.07 meq/L, 1.386 mg/L mean concentrations respectively, violating the standards. A dilution factor of 1.09 litters is computed per liter of sewage to minimize, the concentrations of exceeded parameters by mixing with normal water, into a range that can be used safely for irrigation.

Assessment of hydrogeochemistry and contamination of Varamin deep aquifer, Tehran Province, Iran

The present study investigates the hydrogeochemistry and contamination of Varamin deep aquifer located in the southeast of Tehran province, Iran. The study also evaluates groundwater suitability for irrigation uses. The hydrogeochemical study was conducted by collecting and analyzing 154 groundwater samples seasonally during 2014. Based on evolutionary sequence of Chebotarev, the aquifer is in the stage of SO4 + HCO3 in the north half of the plain and it has evolved into SO4 + Cl in the south half. The unusual increase in TDS and Cl− toward the western boundaries of the aquifer indicates some anomalies. These anomalies have originated from discharge of untreated wastewater of Tehran city in these areas. The studied aquifer contains four dominant groundwater types including Na–Ca–SO4 (55%), Na–Ca–HCO3 (22%), Na–Cl (13%) and Ca–Cl (10%). The spatial distributions of Na–Cl and Ca–Cl water types coincide with observed anomalies. Ionic relationships of SO42− versus Cl− and Na+ versus Cl− confirm that water–rock interaction and anthropogenic contribution are main sources of these ions in the groundwater. The main processes governing the chemistry of the groundwater are the dissolution of calcite, dolomite and gypsum along the flow path, and direct ion exchange. Reverse ion exchange controls the groundwater chemistry in the areas contaminated with untreated wastewater. Based on Na% and SAR, 10.3 and 27% of water samples are unsuitable for irrigation purposes, respectively. Regarding residual sodium carbonate, there is no treat for crop yields. Only 6% of water samples represent magnesium adsorption ratios more than 50% which are harmful and unsuitable for irrigation.

Calcium and strontium isotope fractionation during precipitation from aqueous solutions as a function of temperature and reaction rate; II. Aragonite

In order to study Strontium (Sr) partitioning and isotope fractionation of Sr and Calcium (Ca) in aragonite we performed precipitation experiments decoupling temperature and precipitation rates (R∗, μmol/m2h) in the interval of about 2.3–4.5μmol/m2h. Aragonite is the only pure solid phase precipitated from a stirred solutions exposed to an atmosphere of NH3 and CO2 gases throughout the spontaneous decomposition of (NH4)2CO3. The order of reaction with respect to Ca ions is one and independent of temperature. However, the order of reaction with respect to the dissolved inorganic carbon (DIC) is temperature dependent and decreases from three via two to one as temperature increases from 12.5 and 25.0 to 37.5°C, respectively. Strontium distribution coefficient (DSr) increases with decreasing temperature. However, R∗ responds differently depending on the initial Sr/Ca concentration and temperature: at 37.5°C DSr increase as a function of increasing R∗ but decrease for 12.5 and 25°C. Not seen at 12.5 and 37.5°C but at 25°C the DSr-R∗ gradient is also changing sign depending on the initial Sr/Ca ratio. Magnesium (Mg) adsorption coefficient between aragonite and aqueous solution (DMg) decreases with temperature but increases with R∗ in the range of 2.4–3.8μmol/m2h. Strontium isotope fractionation (Δ88/86Sraragonite-aq) follows the kinetic type of fractionation and become increasingly negative as a function of R∗ for all temperatures. In contrast Ca isotope fractionation (Δ44/40Caaragonite-aq) shows a different behavior than the Sr isotopes. At low temperatures (12.5 and 25°C) Ca isotope fractionation (Δ44/40Caaragonite-aq) becomes positive as a function of R∗. In contrast, at 37.5°C and as a function of increasing R∗ the Δ44/40Caaragonite-aq show a Sr type like behavior and becomes increasingly negative. Concerning both the discrepant behavior of DSr as a function of temperature as well as for the Ca isotope fractionation as a function of temperature we infer that the switch of sign in the trace element partitioning as well as in the direction of the Ca isotope fractionation is probably due to the switch of complexation from a Ca2+-NH3 complexation at and below 25°C to an Ca2+-H2O aquacomplex at 37.5°C. The DSr–Δ88/86Srcalcite-aq correlation for calcite is independent of temperature in contrast to aragonite. We interpreted the strong DSr-temperature dependency of aragonite, the smaller range of Sr isotope fractionation as well as the shallower Δ88/86Srcalcite-aq–R∗ gradients to be a consequence of the increased aragonite solubility and the “Mg blocking effect”. In contrast to Sr the Ca isotope fractionation values in calcite and aragonite depend both on the complexation in solution and independent on polymorphism.

Groundwater quality assessment for domestic and agriculture purposes in Puducherry region

Totally about 174 groundwater samples have been collected during pre-monsoon and post-monsoon season to study the suitability for domestic and agriculture purposes along the coastal aquifers of Puducherry region. Parameters such as pH, total dissolved solids (TDS), electrical conductivity (EC), sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), bicarbonate (HCO3), chloride (Cl) and sulfate (SO4) were analyzed to assess the suitability of groundwater for domestic purposes. Sodium adsorption ratio (SAR), magnesium adsorption ratio (MAR), residual sodium bicarbonate (RSC), soluble sodium percentage (Na%), permeability index (PI) and chlorinity index were assessed for irrigation purposes. The higher concentration of ions such as Na, Ca, Cl and So4 indicates seawater intrusion, mineral dissolution, intense agricultural practices and improper sewage disposal. The level of EC, TDS and hardness in the water samples indicates that maximum of them are suitable for drinking and domestic purposes. The parameters such as SAR, Na%, PI, MAR and Chlorinity index indicates that majority of water sample are very good to moderately suitable for agriculture. In pre-monsoon, RSC of about 5.7% of samples was higher which when used for a longer time alter the soil properties and reduce crop production. Wilcox diagram suggests that water samples are of medium saline to low sodium type indicating that groundwater is suitable for irrigation. Temporal variation of groundwater quality shows significant increasing trend in EC, TDS and ions like Mg, K and Cl in the last decade, mainly due to anthropogenic activities with little geogenic impact in the quality of groundwater.

Hydro-geochemical classification and spatial distribution of groundwater to examine the suitability for irrigation purposes (Golestan Province, north of Iran)

One of the most important agricultural areas in Iran is Golestan Province. In this study, the suitability of groundwater for irrigation purposes was assessed. To determine hydro-geochemical classification of the station and assessment of spatial modeling of the study area, 12 groundwater stations were selected and an average of the last 5 years of sampling (2011–2015) has been considered. Suitability of groundwater for irrigation was assessed based on Sodium Adsorption Ratio (SAR), Residual Sodium Carbonate (RSC), Na%, Permeability Index (PI), Magnesium Adsorption Ratio (MAR), Kelley’s Ratio (KR), Corrosion Ratio (CR), Residual Sodium Carbonate (RSC), Potential Soil Salinity (PSS), Chloro-Alkaline Indices (CAI), Meteoric genesis (Met. gen) and Wilcox classification. The abundance of major ions followed a HCO3 > SO4 > Na > Ca > Mg > Cl > K trend. CAI results indicate reverse cation exchange for this area, and Wilcox classification indicates that only Kalou, Kafshgari, and Kia stations are appropriate for irrigation. The spatial distribution of groundwater quality demonstrates a decreasing trend from SE to NW based on CAI, Cl, CR, EC, TSS, and TDS and shows reverse trends for KR, MAR, Met. gen, Mg/Ca, Na%, pH, PI, and RSC. In addition, the results of hydro-geochemical classification of irrigation parameters have categorized the irrigation water of this area into three different classes. Based on EC, MAR, Mg/Ca, Cl and CR, this area is suitable, but based on PSS, KR, and TH, all stations are unsuitable and according to SAR, TDS, Na% and PI, this area’s groundwater is moderate.

Assessment of groundwater quality from Bankura I and II Blocks, Bankura District, West Bengal, India

Hydrochemical evaluation of groundwater has been conducted in Bankura I and II Blocks to analyze and determining groundwater quality in the area. Thirty-six groundwater samples were analyzed for their physical and chemical properties using standard laboratory methods. The constituents have the following ranges in the water: pH 6.4–8.6, electrical conductivity 80–1900 μS/cm, total hardness 30–730 mg/l, TDS 48–1001 mg/l, Ca2+ 4.2–222.6 mg/l, Na+ 2.33–103.33 mg/l, Mg2+ 1.56–115.36 mg/l, K+ 0.67–14 mg/l and Fe BDL–2.53 mg/l, {text{HCO}}_{3}^{ - } 48.8–1000.4 mg/l, Cl− 5.6–459.86 mg/l and {text{SO}}_{4}^{ = } BDL–99.03 mg/l. Results also show that bicarbonate ions ( {text{HCO}}_{3}^{ - } ) dominate the other anions (Cl− and {text{SO}}_{4}^{2 - } ). Sodium adsorption ratio (SAR), soluble sodium percentage (SSP), residual sodium carbonate (RSC), magnesium adsorption ratio (MAR), total hardness (TH), and permeability index (PI) were calculated as derived parameters, to investigate the ionic toxicity. Concerned chemical parameters when plotted in the U.S. Salinity diagram indicate that waters are of C1–S1, C2–S1 and C3–S1 types, i.e., low salinity and low sodium which is good for irrigation. The values of Sodium Adsorption Ratio indicate that the groundwater of the area falls under the category of low sodium hazard. So, there is neither salinity nor toxicity problem of irrigation water, and hence the ground water can safely be used for long-term irrigation. The chemical parameters when plotted in Piper’s trilinear diagram are found to concentrate in the central and west central part of the diamond-shaped field. Based on the analytical results, groundwater in the area is found to be generally fresh and hard to very hard. The abundance of the major ions is as follows: HCO3 > Cl > SO4 and Ca > Na > Mg > K > Fe. Results also show that bicarbonate ions ( {text{HCO}}_{3}^{ - } ) dominate the other anions (Cl− and {text{SO}}_{4}^{2 - } ). According to Gibbs diagrams samples fall in the rock dominance field and the chemical quality of groundwater is related to the lithology of the area. The alkaline earth elements (Ca and Mg) occur in greater abundance than alkaline elements (Na and K). A comparative study of our analytical results with the WHO standards of drinking water indicate that the present waters are also good for drinking purposes.

Hydrogeochemical investigation of groundwater in shallow coastal aquifer of Khulna District, Bangladesh

Groundwater acts as a lifeline in the coastal regions to meet out the domestic, drinking, irrigational and industrial needs. To investigate the hydrogeochemical characteristics of groundwater and its suitability, twenty samples were collected from the shallow tubewells of study area having screen depth 21–54 m. The water quality assessment has been carried out by evaluating the physicochemical parameters such as temperature, pH, EC, TDS and major ions i.e., Na+, K+, Ca2+, Mg2+, Cl−, SO42−, NO3−, HCO3−. Results found that, the water is slightly alkaline and brackish in nature. The trends of cations and anions are Na+ > Ca2+ > Mg2+ > K+ and Cl− > HCO3− > SO42− > NO3−, respectively and Na–Cl–HCO3 is the dominant groundwater type. The analyzed samples were also characterized with different indices, diagram and permissible limit i.e., electric conductivity (EC), total dissolved solids (TDS), chloride content (Cl), soluble sodium percentage (SSP), sodium adsorption ratio (SAR), residual sodium carbonate (RSC), magnesium adsorption ratio (MAR), Kelley’s ratio (KR), Wilcox diagram and USSL diagram, and results showed that groundwater are not suitable for drinking and irrigational use. The factors responsible for the geochemical characterization were also attempted by using standard plot and it was found that mixing of seawater with entrapped water plays a significant role in the study area.

Evaluation of groundwater quality for drinking and irrigation purposes in the north-western area of Libya (Aligeelat)

Groundwater is considered an important water source for agricultural, drinking and domestic uses in many regions of the world including Libya, especially in its coastal area. This study aims to assess the quality of groundwater in north-western area of Libya for drinking and agricultural through examining its physico-chemical characteristics such as pH, electrical conductivity (EC), total dissolved solids (TDS), total hardness, cations and anions. These parameters are used to assess the suitability of groundwater for domestic purposes by comparing their current values with the maximum permissible limits of these parameters that are recommended by World Health Organization (WHO). The EC, sodium adsorption ratio, soluble sodium percentage, Kelly’s ratio and magnesium adsorption ratio of the groundwater are also used to evaluate its suitability for irrigation. Gibbs diagram shows the evaporation–crystallization dominance in controlling the quality of groundwater. The main hydrochemical facies is Ca–Mg–SO4–Cl type of water in both methods of Piper and Chadha’s diagram. The results revealed that most groundwater samples were not suitable for drinking and household uses due to their high levels of most cations and anions, total hardness, EC and TDS. Most of the collected water samples showed the investigated parameter levels exceeded the permissible limits of WHO. Therefore, most of the groundwater samples are considered unsuitable for irrigation due to its high salt content, unless certain measures for salinity control are undertaken.

Evaluation of Groundwater Suitability for Drinking and Irrigation Purposes in Toba Tek Singh District, Pakistan

Correlating the physicochemical parameters for assessment of the groundwater quality has emerged as a very useful approach for water use. Taking water samples from the Toba Tek Singh District of Pakistan, this study assess the water quality for drinking and irrigation purposes. A sum-total of 72nos. groundwater samples were collected and analyzed for the purpose of different water quality parameters including sodium (Na+), potassium (K+), calcium (Ca2+), magnesium (Mg2+), bicarbonate (HCO- 3), chloride (Cl-), sulphate (SO4 2-), pH, electrical conductivity (EC), total dissolved solids (TDS) and total hardness (TH). The results obtained were, then, compared with the standard desirable limits of physicochemical parameters prescribed by World Health Organization (WHO), Pakistan Standards and Quality Control Authority (PSQCA) and Pakistan Council of Research in Water Resources (PCRWR) for drinking purposes. In order to classify the groundwater suitability for irrigation purpose, parameters such as sodium adsorption ratio (SAR), percent sodium (PS), permeability index (PI), residual sodium bicarbonate (RSBC), Kelly’s ratio (KR), and magnesium adsorption ratio (MAR) were also calculated on the basis of chemical data. After that, the correlation coefficients between different physicochemical parameters were calculated to identify the highly correlated and interrelated parameters for water quality. Different plots like Piper, Durov, Schoeller and Stiff diagrams were drawn to classify the groundwater ability for different purposes. These several classifications show most of groundwater samples falling within the safe limits and thus suitable for drinking and irrigation purposes, except of a few samples with a caution that it may get worse in the future.