US Salinity Laboratory Classification Research Articles

Kırklareli Yöresindeki Atıksuların Tarımda Sulama Amaçlı Kullanılabilirliğinin Belirlenmesi

Turkiye’s water resources are getting increasingly polluted and the need for per capita water is increasing rapidly from year to year with population growth. With the increasing population, the increase in the need for food, the increase in water consumption, and the reuse of wastewater in various fields, especially as irrigation water, by treating it with appropriate methods, come to the fore today.The sewage waters of the city of Kırklareli are treated in the existing domestic and industrial treatment plants and discharged into the Kırklareli stream. This study was carried out in order to determine the irrigation water quality and pollution status of the waters released from the waters of the creek and treatment plants and to reveal their suitability for agricultural use. Waste water samples taken from stations determined on Kırklareli Stream were taken seasonally. Physical and inorganic-chemical parameters were investigated. The results from the study was determined according to the Classes of Inland Surface Water Resources (KYSKK) in the Water Pollution Control Regulation. Accordingly; In terms of physical and inorganic-chemical parameters of Kırklareli stream water samples, it is seasonally classified as IV. class has been determined. It has been determined to be in the C3S1 class according to the US Salinity Laboratory Classification system based on electrical conductivity (EC) and sodium adsorption rate (SAR) values. According to the results obtained, it has been determined that it should be used with caution due to its excessive salt content. Analysis of variance, one-way analysis of variance (ANOVA) and correlation analysis were performed in a repeated measurement experiment on the measurement values of water samples. Significant differences and relationships between parameters were determined statistically.

Suitability of reclaimed wastewater effluent from decentralized wastewater plant for irrigation

Decentralized wastewater plants have been proven to be cost-effective, easy to construct and operate and widely used in small ruler communities. The suitability of reclaimed wastewater for irrigation purpose was evaluated in this study based on the various water quality parameters, international water quality standards and water–irrigation water quality guideline (JS 1766). Twenty-seven samples were collected from a decentralized wastewater plant that is located in Balqa Governorate in Salt city, Jordan. Samples were analyzed for pH, electrical conductivity, major anions and cations, as well as biological oxygen demand, chemical oxygen demand and total suspended solids. Study results show that water is slightly alkaline in nature. According to Jordanian domestic reclaimed wastewater standard, the use of water for irrigation has a mild-to-moderate degree of restriction. Using the US Salinity Laboratory classification scheme, there is high salinity and medium sodium water, 50% of samples falls in the area of (C3-S2) and this water is suitable for irrigation for many types of soil with low risk of increasing exchangeable sodium content. According to chloride hazards, the water for irrigation can be used for moderately tolerant plants. 74% of the samples have the residual sodium carbonate (RSC) less than 1.25 meq/L and hence suitable for irrigation. The study recommends that treated wastewater from decentralized wastewater a plant is considered as non-conventional source for irrigation.

Assessment of kitchen wastewater quality for irrigation

In this study, the potential reuse of kitchen wastewater (KWW) in irrigation was analyzed to reduce the present freshwater demand. To know the suitability of KWW for irrigation, the samples were first collected from an educational institute in India and then characterized according to its physical, chemical, and bacteriological properties. The characterized data were then compared with the standard limit for irrigation Food and Agriculture Organization (FAO in Water quality for agriculture. Irrigation and drainage paper 29, M56, 1994) and the US Salinity Laboratory (USSL). Apart from the above irrigation standards, the characterized data were also compared with sodium adsorption ratio (SAR), residual sodium carbonate, sodium percentage (Na%), magnesium hazard (MH), Kelly’s ratio (KR), and permeability index to get better clarity. From the characterization, it was found that carbonate, fluoride, chromium, and Escherichia coli were absent, whereas parameters like pH, chloride, iron, copper, magnesium, lead, nickel, sodium, calcium, zinc, aluminum, and sodium adsorption ratio were within the permissible limit. The result obtained from the USSL classification system suggested that 30.77% of KWW samples are safe for irrigation. Moreover, its quality was found to be safe for irrigation based on SAR, Na%, KR, and MH. For better decision making of KWW reuse in irrigation, the output of Mamdani fuzzy inference system (MFIS) was compared with the USSL classification system. The overall agreement between USSL and MFIS was found to be 55.6% for KWW.

GIS-based assessment of groundwater quality and suitability for drinking and irrigation purposes in the outlet and central parts of Wadi El-Assiuti, Assiut Governorate, Egypt

BackgroundThe limited water resources in arid environments in addition to the effect of agricultural and anthropogenic activities on groundwater quantity and quality necessitate paying more attention to the quality assessment of these resources. The present studies assess the quality of groundwater resources in Wadi El-Assiuti, south Egypt, and evaluate their suitability for drinking and irrigation purposes. To achieve this goal, 159 groundwater samples were collected from the outlet and central parts of the Wadi El-Assiuti during the autumn season (October–November) of 2019 and were analyzed for major ions, trace elements and heavy metals.ResultsThe results indicate that the TDS values range between 1972 and 6217 ppm, while the concentration of trace elements (Fe++, Mn++ and Ni+) ranges between 0.05 and 0.46, 0.11 and 0.221 and 0.01 and 0.6 ppm, respectively. These results show that all groundwater samples are clearly unacceptable and inappropriate for human drinking due to their high content of total dissolved solids, trace elements and heavy metals, particularly in the majority of samples according to World Health Organization (WHO) guidelines and the Egyptian standards (Eg. St. 2007) for drinking water quality. Spatial analysis of the TDS values in geographic information system environment indicates that the salinity is higher in the northeast and gradually decreases southward. Sodium adsorption ratio, US Salinity Laboratory classification (1954), residual sodium carbonate, soluble sodium percentage and permeability index show that most groundwater samples are suitable for irrigation purposes.ConclusionsThe integrated approach provided in this study highlights the spatially distributed suitability of groundwater resources in Wadi El-Assiuti and can be applied in similar basins worldwide.

Seyfe Gölü (Mucur-Kırşehir) Sulak Alanı Havzasındaki Su Kaynaklarının Hidrojeolojik ve Hidrokimyasal Değerlendirmesi

Seyfe Lake wetland, which has a catchment area of 1487 km 2 , is located south of the Seyfe closed basin in Kirsehir province. The wetland and its surroundings have the status of Nature Reserve Area, First Degree Natural Protected Area and Ramsar Area. In this study; geological, hydrogeological and hydrochemical aspects of Seyfe Lake wetland and its basin were evaluated. In this scope, hydrochemical properties, irrigation usability and quality of the water resources in the basin were investigated. In the study area, metamorphic series of Paleozoic Kirsehir massif, Cenozoic cover units and Quaternary alluvial units are exposed. The field campaign was carried out in the drainage area in September 2019 and in-situ measurements and water sampling were carried out. According to the in-situ measurements; temperatures of the waters vary between 14.5°C-21.2 o C and pH ranges between 7.15-8.65. Character of these waters are neutral to basic. Specific electrical conductivity values of the waters in the study area are between 370-30500 µS/cm. Water resources in the basin belong to Ca-HCO 3 , Na-HCO 3 and Na-SO 4 facies. Discharge rate of the springs are measured between 0.03 and 2.5 l/s. In the study area, suitability of the water resources for irrigation is evaluated using Wilcox and US Salinity Laboratory classification. It is determined that majority of the sampled waters are suitable for irrigation.

Hydrogeochemical characteristics of groundwater and quality assessment for the purposes of drinking and irrigation in Bougaa area, Northeastern Algeria

In the northern part of Algeria, the intensive exploitation of groundwater resources and pollution has considerably affected the aquifer water quality, especially in rural areas where groundwater is the main source of water supply for most uses. This study was performed to evaluate the groundwater quality and its suitability for drinking and irrigation purposes through the hydrogeochemical study on the groundwater in Bougâa region (Northeastern Algeria). Fourteen groundwater samples were collected and analyzed for pH, T, EC, TDS, and major ions. Most samples are suitable for drinking based on the permissible limits of the Bureau of Indian standards (Indian standard specification for drinking water (IS 10500: 2012), but only 35 % of the samples are good enough for drinking purposes based on the water quality index of the groundwater. Assessment of groundwater samples from various parameters and methods such as “Electrical conductivity, Sodium adsorption ratio, Soluble sodium percentage, Magnesium adsorption ratio, Residual sodium carbonate, Permeability index, Kelly’s ratio, Wilcox’s diagram, and US salinity laboratory classification” showed that groundwater in the area is chemically suitable for irrigation uses. The Piper trilinear diagram suggests that the groundwater mainly belongs to the hydrochemical facies Ca–Mg–Cl and Na–Cl. The combination of ionic ratios, Gibbs plots, and saturation indices show that water–rock interaction, particularly the dissolution of carbonate, evaporation minerals, and ion exchange processes affects hydrogeochemistry of the area. Additional processes such as evaporation and anthropogenic pollution from various sources can also have major impacts on groundwater salinity.

Comparing Global Classifications of Water That Applied on Some of AL-Qadissiya Wells Water

This study has been conducted to evaluate the quality of some of AL-Qadisyah province wells water and classify them according to global classifications. Nineteen wells in different locations have been pointed and assessed during the period between September 2012 to August 2013. Results shows differences in water quality depending on the locations; Electrical conductivity ranges between 1.60 and 19.82 ds.m-1, and Sodium adsorption ratio ranges between 2.03 and 17.47. Four global classifications have been used. The US Salinity Laboratory classification of the year of 1954 categorized most of these wells in category of C4-S1, which is high-salinity and too low sodic water. According to FAO classification of the year of 1985, some of the wells categorized in category of high-salinity and some other mild to moderate salinity. The same classification of the year of 1992 puts most of the wells in moderate salinity category, and characterizes their water as water of puncture and initial groundwater. According to the suggested classification by Ghliam (1997), 73% takes place between accepted to moderated salinity. These classifications state the applicability of using wells water for agricultural purposes in this area considering; good management practices using washing requirements around 15-20%, using good drain system, reducing ground water level to maintain the balance of saline soil, and cultivating salinity tolerant crops. This study could be used as an index when underground water wanted to be used for agricultural territory of AL- Diwanyia

Evaluation of Groundwater Quality and Its Suitability for Domestic and Irrigation Use in Parts of the Chandauli-Varanasi Region, Uttar Pradesh, India

The present study focused on the hydrochemistry of groundwater in parts of Chandauli-Varanasi region to assess the quality of groundwater for determining its suitability for drinking and agricultural purposes. Urbanization and agriculture activities have a lot of impacts on the groundwater quality of the study area. A total of 70 ground water samples were collected randomly from different sources viz. hand pump, dug wells and bore wells, and analyzed for major cations and anions. The domination of cations and anions was in the order of Na > Ca > Mg > K and HCO3 > Cl > SO4 > NO3 > F. The Piper classification for hydrogeochemical facies indicates that alkaline earth exceeds alkalis and weak acids exceed strong acid. Water quality index rating was calculated to quantify overall water quality for human consumption. Out of 70 groundwater samples, 7% and 10% samples exhibit water unsuitable for drinking purposes in pre- and post-monsoon, respectively, due to effective leaching of ions, direct discharge of domestic effluents and agricultural activities. Residual sodium carbonate values revealed that 6% sample is not suitable for irrigation purposes in both the seasons due to low permeability of the soil. The calculated values of PI indicate that the water for irrigation uses is excellent to good quality in both seasons. As per Wilcox’s diagram and US salinity laboratory classification, most of the groundwater samples are suitable for irrigation except one sample which is unsuitable for irrigation purposes. The overall quality of groundwater in post-monsoon season in all chemical constituents is on the higher side due to dissolution of surface pollutants during the infiltration and percolation of rainwater at few places due to agricultural and domestic activities.

Hydrogeochemical characterization and quality assessment of groundwater around Umrer coal mine area Nagpur District, Maharashtra, India

Quality assessment as well as hydrogeochemical characterization of 45 representative groundwater samples around Umrer coal mine area was undertaken. The pH of the water lies in the normal range i.e. from 7.5 to 8.5, the electrical conductivity varies from 826 to 1,741, the total hardness varies from 289 to 1,302 and the TDS values range from 528.6 to 1,114.2 mg/l which reflects variation in lithology and thus, the distinction in hydrogeological regime. The cation chemistry is dominated by Ca2+ and Mg2+ while anion chemistry is dominated by Cl− and HCO3−. Out of total ten hydrochemical facies, the two dominant facies are Mg–Ca–HCO3 (37.7 %) and Ca–Mg–SO4–HCO3 (17.7 %). The groundwater in the study area, in general, is useful for drinking and domestic use; however, it has marginal utility for irrigation purpose. Standard US Salinity Laboratory classification shows that water of the study area belongs to C2–S1 and C3–S1 classes. The concentration of 9 trace elements analysed from 18 samples did not exceed the desirable limit.

Groundwater Quality in Parts of Central Ganga Basin, Aligarh City, Uttar Pradesh, India

Hydrochemistry of groundwater in Aligarh city of Uttar Pradesh, India was used to determine its suitability for drinking and irrigation purpose. Physical and chemical parameters of groundwater such as electrical conductivity, pH, total dissolved solids (TDS), Na+, K+, Ca2+, Mg2+, Cl–, HCO3 –, CO3 2– and SO4 2–, were determined in one hundred groundwater samples collected from open wells as well as hand pumps in 2010. Ionic concentrations of the groundwater vary spatially and temporarily and the water is alkaline in nature. The higher values of some parameters at certain locations indicate contamination of the groundwater, making it unsuitable for specific applications. Twenty five percent of the wells lie under the medium salinity zone (EC 750-2250 micro mhos/cm). The Sodium Absorption Ratio (SAR) values range between 0.26 to 15.5 indicating that some water samples fall under the category of medium salinity hazard and are not suitable for irrigation. The groundwater of the area has also been classified on the basis of the Piper diagram. Many of the samples fall in the magnesium and sodium or potassium type, and 50% samples fall in no dominant type. As per US Salinity Laboratory Classification for irrigation water, most of the water samples fall under C2-S1 class (medium salinity and low SAR), eighteen locations fall under the category C3-S2 class (medium salinity and low SAR) and one location Luxmi Nagar shows C3-S3 (high salinity and high SAR). The major reason for the decline in water quality is the dumping of large amount of acid wastes by illegal lock factories, and another important source of pollution is slaughterhouse where at least 2500 buffaloes are slaughtered daily.

盐胁迫对2种栎树苗期生长和根系生长发育的影响

以低浓度（50 mmol/L）和高浓度（150 mmol/L）NaCl处理弗吉尼亚栎（<em>Quercus virginiana</em>）和麻栎（<em>Quercus acutissima</em>）1年生幼苗，研究了2种栎树在盐胁迫下的生长、对盐分的敏感性和耐受性及其根系形态学参数变化以及根系对盐离子的吸收与积累。结果表明，高浓度盐胁迫明显抑制了2种栎树地上部生物量的积累（<em>P</em> < 0.05），而低浓度盐胁迫对弗吉尼亚栎地上部干重的影响不明显，但显著抑制了麻栎地上部干重（<em>P</em> < 0.05）；2种栎树的根冠比在盐胁迫下呈增加趋势，特别是在高浓度盐胁迫下，2种栎树的根冠比明显增加（<em>P</em> < 0.05），盐胁迫下增加生物量在根部的分配是植物应对盐胁迫的方式之一。2种栎树根部生物量积累在盐胁迫下变化不明显，但2种栎树根系形态学参数在盐胁迫下的响应不同，弗吉尼亚栎根系总长度、总表面积和总体积在盐胁迫下均有不同程度增加，特别是在低浓度盐胁迫下，根系形态学参数明显增加（<em>P</em> < 0.05），但麻栎根系形态学参数有下降趋势，但与对照相比变化不明显；通过对不同径级根系总长的分析发现，弗吉尼亚栎根系总长度的增加主要是由于直径小于2 mm的细根总长的增加，细根长度的增加对于植物吸收水分和营养物质具有重要意义；通过对Na⁺和Cl^-在根系的含量分析表明，盐胁迫下2种栎树根系盐离子的积累均有明显增加，但弗吉尼亚栎根系盐离子的含量在低浓度和高浓度盐胁迫下的差异不明显，而麻栎在高浓度盐胁迫下根系盐离子的含量明显高于弗吉尼亚栎。综合2种栎树盐胁迫下的生物量分配策略和根系形态学响应以及盐离子的积累规律，证明2种栎树尽管在生物量分配策略方面具有相同的特点，但根系的响应策略截然不同，弗吉尼亚栎在盐胁迫下能够扩大根系吸收范围，维持较高的K⁺/Na⁺比值，而麻栎在盐胁迫下根系由于吸收过多的盐离子，导致根系的生长发育受到抑制，影响了根系在逆境中的分布范围，从而在一定程度上避免了进一步的盐害。;It is well known that saline soil, which takes up about 25% of the whole land area, is one of the most widely distributed soils on Earth. In China, the saline area is over 34 million hm², including one million hm² coastal saline soil. Soil salinity refrains the development and growth of most plant species, except for few species like halophytes. To understand the mechanism of salt tolerance, many studies have been carried out on the herbaceous halophytes, the tolerant woody plants and the sensitive and tolerant crop plants, but much less is known concerning the salt susceptibility and tolerance of oak trees.<em> Quercus</em> <em>virginiana</em> and <em>Quercus acutissima </em>are two different origin oak trees. <em>Q. virginiana</em>, is considered as a moderately sensitive tree species to soil salinity according to US Salinity Laboratory classification. It is one of the dominant tree species along southeastern coast of the United States and has the extreme tolerance to high concentration of salt fog. <em>Q. virginiana</em> acorn was introduced to China in 2000 for the first time, and its tolerance to salts has been confirmed through the regional trial along the coastline of southeastern China.<em> Q. acutissima</em> is widely distributed in China and few researches are reported about its response on salt stress.<br>The response of plants to excess salt is complex and involves some changes in morphology, physiology and metabolism. Among these changes, the variations changes in the biomass allocation and root morphological characteristics of plants are two important adaptive mechanisms under salt stress. In this research, the changes of root morphology and biomass accumulation of 1-year-old seedlings of <em>Q. virginiana</em> and <em>Q. acutissima </em>were investigated under higher concentration (150 mmol/L) and lower concentration (50 mmol/L) of sodium chloride solution treatments. The results showed that the growth of shoots of two oak trees were significantly inhibited under higher concentration of salt stress, while no obvious changes were observed for the growth of shoots of <em>Q. virginiana </em>under lower concentrations of NaCl. The ratio of root to shoot for two oak trees increased under both concentration of NaCl, which was considered as a biomass allocation strategy for a certain class of plants under salt stress.<br>For the two oak trees, salinity did not induce the significant change on the root biomass accumulation. While the root morphological responses under salt stress were different between two oak trees. For <em>Q. virginiana</em>, the total root length, root surface area and root volume were increased in various degrees under both lower and higher concentration of NaCl, and significant increasement was observed under lower concentration of NaCl, especially for the stimulation of fine roots with the diameter less than 2mm. The fine roots are more effective than the thicker roots in nutrient and water absorption. For <em>Q. acutissima</em>, although its root development and expandation were inhibited under salt stress, no significant difference was observed when compared to that of control. It was also observed that the different patterns of accumulation of Na⁺ and Cl^- in roots for two oak trees. Therefore, according to the biomass allocation strategy and root morphological responses and ions accumulation patterns of two oak trees under salt stress, it may be deduced that the both oak trees have the similar biomass allocation strategy when exposed to salinity, but have totally different responses on the root development and salt ions accumulation. <em>Q. virginiana</em> could expand the root scope for more effective nutrient absorption to relieve the toxicity of redundant salt ions, while <em>Q. acutissima</em> restricted the expanding of roots in salinity environment due to the redundant uptake of salt ions, and thus lessens the further damage to roots.

Water quality assessment of carbonate aquifers in southern Latium region, Central Italy: a case study for irrigation and drinking purposes

In southern Latium region, Central Italy, groundwater and spring water resources in the carbonate aquifers are the major contributors of drinking and irrigation water supply. The aim of this study was to review hydrochemical processes that control the groundwater chemistry and to determine the suitability of springs and groundwater for irrigation and drinking purposes on the basis of the water quality indices. Physical (pH, electrical conductivity, total dissolved solids) and hydrochemical characteristics (Na+, K+, Ca2+, Mg2+, HCO3−, Cl−, and SO4−) of springs and groundwater were determined. To assess the water quality, chemical parameters like sodium adsorption ratio (SAR), total hardness, Mg-hazard (MH), sodium percentage (Na %), salinity hazard, permeability index, and Kelly’s ratio were calculated based on the analytical results. A Durov diagram plot revealed that the groundwater has been evolved from Ca to HCO3 recharge water, followed by mixing and reverse ion exchange processes, due to the respective dominance of Na–Cl and Ca–Cl water types. According to Gibbs’s diagram plots, chemical weathering of rock forming minerals is the major driving force controlling water chemistry in this area. Groundwater and spring samples were grouped into six categories according to irrigation water quality assessment diagram of US Salinity Laboratory classification and most of the water samples distributed in category C2–S1 and C3–S1 highlighting medium to high salinity hazard and low sodium content class. The results of hydrochemical analyses and the calculated water quality parameters suggest that most of the water samples are suitable for irrigation and drinking purposes, except for the samples influenced by seawater and enhanced water–rock interaction. High values of salinity, Na %, SAR, and MH at certain sites, restrict the suitability for agricultural uses.

Hydrochemical characteristics and GIS-based assessment of groundwater quality in the coastal aquifers of Tuticorin corporation, Tamilnadu, India

Tuticorin corporation stretches geographically from 8°43′–8°51′N latitude and 78°5′–78°10′E longitude, positioned in the East–West International sea routes on the South–East coast of India. The rapid urban developments in the past two decades of Tuticorin have caused depletion of groundwater quantity, and deterioration of quality through excessive consumption and influx of pollutants from natural and anthropogenic activities. The water samples collected in the field were analyzed for electrical conductivity, pH, total dissolved solids, major cations like calcium, magnesium, sodium, potassium, and anions SUCH AS bicarbonate, carbonate, chloride, nitrate and sulfate, in the laboratory using the standard methods given by the American Public Health Association. In order to assess the groundwater quality, 36 groundwater samples had been collected in year 2011. The geographic information system-based spatial distribution map of different major elements has been prepared using ArcGIS 9.2. The Piper plot shows that most of the groundwater samples fall in the field of Ca2+-Mg2+–Cl−-SO42− and Na+-K+–Cl−-HCO3− by projecting the position on the plots in the triangular field. The cation concentration indicate that 83, 39 and 22 % of the K+, Na+, Ca2+ concentrations exceed the WHO limit. As per Wilcox’s diagram and US Salinity laboratory classification, most of the groundwater samples are not suitable for irrigation due to the presence of high salinity and medium sodium hazard. Irrigation waters classified based on sodium absorption ratio, have revealed that 52 % groundwater are in general safe for irrigation, which needs treatment before use. permeability index also indicates that the groundwater samples are suitable for irrigation purpose.

Geochemical Characterization of Kor River Water Quality, Fars Province, Southwest Iran

A study was conducted on April, 2010 to evaluate the surface water quality from 29 sampling points along the Kor River in Fars province SW Iran. The Kor River plays a key role in supplying water for municipal and industrial users, and for irrigation. In the last few decades rapid industrialization and urbanization along the river course has increased the pollution load of the river water. In this study, 13 physicochemical parameters (pH, EC, NO3, TA, PO4, SO4, As, Cr, Cu, Hg, Mo, Ni, and Zn) are determined and the quality of water is evaluated using various tools, such as piper, sodium absorption ratio (SAR), U.S. salinity laboratory classification (USSL), heavy metal pollution index (HPI) and heavy metal evaluation index (HEI). Results show that the effluents discharged from industrial units and municipal sources has led to increased EC (6500–21510 μs/cm), TDS (4566–12632 mg/l), NO3 (15–1421 mg/l), Cl (1205–7161 mg/l), SO4 (2400–7008 mg/l), Hg (0.1–6.3 ppb), Cr (6–268 ppb), Mo (18.3–78.2 ppb) and Ni (7.4–24.1 ppb) in at least four sampling stations. The Piper plot reveals the dominance of Na+–K+–Cl− type of hydrogeochemical facies. In the USSL plot 34.48% of water samples fall in C2S1, C3S1 and C3S2 zones, which are suitable for irrigation. Also, a reclassification of the HPI and HEI categories using median values show that 3.5% of HPI values and 13.8% of HEI values are classed as high. Sewage inputs from industrial and municipal sources are responsible for the observed high concentration of many physicochemical parameters in the Kor River.

Hydrogeochemistry and microbial contamination of groundwater from Lower Ponnaiyar Basin, Cuddalore District, Tamil Nadu, India

Groundwater is the major source of fresh water in regions where there is inadequate surface water resources. Forty-seven groundwater samples were collected from Lower Ponnaiyar basin, Cuddalore District, south India, during the premonsoon (PRM) and postmonsoon (POM) seasons of 2005. Out of 47 groundwater samples, 15 samples showing higher nitrate concentration were those collected during PRM 2005. Microbial analysis of these samples was carried out by employing 16S rRNA gene sequence tool. Detailed analysis was conducted to determine the hydrogeochemical processes and microbial contamination responsible for deterioration of quality. The abundance of the ions during PRM and POM are in the following order: Na > Ca > Mg > K = Cl > HCO3 > SO4 > CO3. The dominant water types in PRM are in the order of NaCl > CaMgCl > mixed CaNaHCO3, whereas during POM NaCl > CaMgCl > mixed CaNaHCO3, and CaHCO3. However, NaCl and CaMgCl are major water types in the study area. The quality of groundwater in the study area is mainly impaired by surface contamination sources, mineral dissolution, ion exchange and evaporation. Groundwater chemistry was used to assess quality to ensure its suitability for drinking and irrigation, based on BIS and WHO standards. Suitability for irrigation was determined on the basis of the diagram of US Salinity Laboratory (USSL), sodium absorption ratio (SAR), residual sodium carbonate (RSC), and Na%. According to SAR and USSL classification, 27.66% (PRM) and 40.43% (POM) of samples fall under C3S2 category, indicating high salinity and medium sodium hazard, which restrict its suitability for irrigation. Microbiological analysis and its effects on the water quality were also addressed. The 16S rRNA gene sequences of 11 bacterial contaminants exhibited five groups with 11 operational taxonomic units with aerobic and facultatively anaerobic organisms. The presence of aerobic organisms in the groundwater samples reflects the active conversion of ammonia to nitrite by Nitrosomonas sp. which is further converted to nitrates by other organisms. Further the presence of nitrate reducers could also play a role in the process of conversion of nitrate to ammonia and nitrate to molecular nitrogen.

Groundwater quality in the lower Varuna River basin, Varanasi district, Uttar Pradesh

The lower Varuna River basin in Varanasi district situated in the central Ganga plain is a highly productive agricultural area, and is also one of the fast growing urban areas in India. The agricultural and urbanization activities have a lot of impact on the groundwater quality of the study area. The river basin is underlain by Quaternary alluvial sediments consisting of clay, silt, sand and gravel of various grades. The hydrogeochemical study was undertaken by randomly collecting 75 groundwater samples from dug wells and hand pumps covering the entire basin in order to understand the sources of dissolved ions, and to assess the chemical quality of the groundwater through analysis of major ions. Based on the total dissolved solids, two groundwater samples are considered unsuitable for drinking purpose, but all samples are useful for irrigation. Graphical treatment of major ion chemistry by Piper diagram helps in identifying hydro-geochemical facies of groundwaters and the dominant hydrochemical facies is Ca-Mg-HCO3 with appreciable percentage of the water having mixed facies. As per Wilcox’s diagram and US Salinity laboratory classification, most of the groundwater samples are suitable for irrigation except two samples (No’s 30 and 68) which are unsuitable due to the presence of high salinity and medium sodium hazard. Irrigation waters classified based on residual sodium carbonate, have revealed that all groundwaters are in general safe for irrigation except one sample (No. 27), which needs treatment before use. Permeability index indicates that the groundwater samples are suitable for irrigation purpose.

Mapping of groundwater quality in the Turonian aquifer of Oum Er-Rabia Basin, Morocco: a case study

This study takes the groundwater of the Moroccan limestone aquifer of Oum Er-Rabia as an example of statistical and cartographical approaches in water resources management. Statistical analyses based on frequency distribution and PCA methods revealed the homogeneity of waters with the existence of abnormal points and have helped to assess correlations between the studied variables. The mapping approach illustrated that waters are influenced by the lithology of the surrounding rocks and are of Ca–Mg–HCO3, Ca–Mg–Cl–SO4, and mixed types according to the Piper classification. The quality of water is of high to medium, north of the basin, but it is of medium to bad, NE and south, due to excessive contents of chloride, sulfate and nitrate. According to the US Salinity Laboratory classification, water used for irrigation in the eastern and the southern parts of the basin should take into consideration the drainage conditions, the nature of plants and the addition of gypsum doses.