Rajesh Rajendran | Sathyabama University (original) (raw)
Papers by Rajesh Rajendran
Environmental Monitoring and Assessment, 2025
Groundwater is often used directly by the public in several river basins of India. Hence, this st... more Groundwater is often used directly by the public in several river basins of India. Hence, this study was carried out with the objective of assessing the quality of groundwater in the Amaravathi basin, India, using a multiple indices approach. Groundwater quality data from 96 monitoring wells were obtained from the Central Groundwater Board and used in this study. Drinking water quality index (DWQI) and irrigation water quality index (IWQI) were calculated to assess the water suitability for consumption, irrigation, and farming. High levels of fluoride and nitrate have a detrimental impact on health and were evaluated using USEPA methods by calculating the chronic daily intake and hazards quotient. Findings revealed that 42% of samples did not meet the DWQI standards due to high salinity, hardness, nitrate, and fluoride levels. Health risk assessment (HRA) of hazard quotients of nitrate are 81%, 61%, and 39% of samples, while those of fluoride are 85%, 68%, and 18% of samples for infants, children, and adults, respectively are unfit. High salinity rendered 35% of the sample unsuitable for irrigation, though most remained suitable for livestock. Spatial analysis revealed declining groundwater quality from the center to the east of the basin. This mapping study identified areas where the groundwater quality is inappropriate for the intended purpose and alternate water sources should be made viable.
The Earth's apparent resistivity is related to various parameters such as the mineral and fluid c... more The Earth's apparent resistivity is related to various parameters such as the mineral and fluid content, porosity and water saturation in the rock and soil. As most of the soil and rock-forming minerals are non-conductive, measuring the electrical apparent resistivity helps to delineate the porosity and the water content of a rock or soil system. Thus the electrical resistivity measurements provide the means to investigate the subsurface lithology and hydrological conditions of a region. The Vertical Electrical Sounding (VES) method is commonly used for the evaluation of subsurface geology and hydrogeology. In this study was carried out with the objective of using VES to assess the geological conditions of a proposed uranium mine tailings pond. Twenty six VES was carried out in the Seripalli area of Nalgonda District, Andhra Pradesh, India, where it is porposed to locate the uranium tailings pond. The interpretation of the results of VES indicate the presence of three layers. The first layer resistivity characteristics are those of sand and sandy clay with a thickness ranging from 0.5m to 3m. The next layer(weathered granite) with a thickness ranging from 1.3m to 12m and the lower most layer (fractured or massive granite) with a thickness ranging from 12.4m to 54m. Interpretation made was validated with a bore hole log of this area. The top soil constitutes the unsaturated zone with a apparent resistivity range from 0.57 to 452 ohm-m. The apparent resistivity ranges from 3.5 to 297.52 ohm-m in the weathered granite zone (upper aquifer zone) and from 300 to 3400 ohm-m for in the fractured or massive granite. Further work requires the characterization of the fracture system in the granite basement, because fractures may represent preferential pathways for the movements of the pollutants from the tailings disposal area.
The Earth’s apparent resistivity is related to various parameters such as the mineral and fluid c... more The Earth’s apparent resistivity is related to various parameters such as the mineral and fluid content, porosity and water saturation in the rock and soil. As most of the soil and rock-forming minerals are non-conductive, measuring the electrical apparent resistivity helps to delineate the porosity and the water content of a rock or soil system. Thus the electrical resistivity measurements provide the means to investigate the subsurface lithology and hydrological conditions of a region. The Vertical Electrical Sounding (VES) method is commonly used for the evaluation of subsurface geology and hydrogeology. In this study was carried out with the objective of using VES to assess the geological conditions of a proposed uranium mine tailings pond. Twenty six VES was carried out in the Seripalli area of Nalgonda District, Andhra Pradesh, India, where it is porposed to locate the uranium tailings pond. The interpretation of the results of VES indicate the presence of three layers. The fi...
GIS and Geostatistical Techniques for Groundwater Science, 2019
Unsupervised text attribute transfer automatically transforms a text to alter a specific attribut... more Unsupervised text attribute transfer automatically transforms a text to alter a specific attribute (e.g. sentiment) without using any parallel data, while simultaneously preserving its attribute-independent content. The dominant approaches are trying to model the content-independent attribute separately, e.g., learning different attributes' representations or using multiple attribute-specific decoders. However, it may lead to inflexibility from the perspective of controlling the degree of transfer or transferring over multiple aspects at the same time. To address the above problems, we propose a more flexible unsupervised text attribute transfer framework which replaces the process of modeling attribute with minimal editing of latent representations based on an attribute classifier. Specifically, we first propose a Transformer-based autoencoder to learn an entangled latent representation for a discrete text, then we transform the attribute transfer task to an optimization problem and propose the Fast-Gradient-Iterative-Modification algorithm to edit the latent representation until conforming to the target attribute. Extensive experimental results demonstrate that our model achieves very competitive performance on three public data sets. Furthermore, we also show that our model can not only control the degree of transfer freely but also allow transferring over multiple aspects at the same time. 1
Environmental science and pollution research international, Jan 18, 2015
This research aimed at developing comprehensive assessments of physicochemical quality of groundw... more This research aimed at developing comprehensive assessments of physicochemical quality of groundwater for drinking and irrigation purposes at Dalcheon in Ulsan City, Korea. The mean concentration of major ions represented as follows: Ca (94.3 mg/L) > Mg (41.7 mg/L) > Na (19.2 mg/L) > K (3.2 mg/L) for cations and SO4 (351 mg/L) > HCO3 (169 mg/L) > Cl (19 mg/L) for anions. Thematic maps for physicochemical parameters of groundwater were prepared, classified, weighted, and integrated in GIS method with fuzzy logic. The maps exhibited that suitable zone of drinking and irrigation purpose occupied in SE, NE, and NW sectors. The undesirable zone of drinking purpose was observed in SW and central parts and that of irrigation was in the western part of the study area. This was influenced by improperly treated effluents from an abandoned iron ore mine, irrigation, and domestic fields. By grouping analysis, groundwater types were classified into Ca(HCO3)2, (Ca,Mg)Cl2, and CaCl2...
Environmental Earth Sciences, 2011
... J Geo Exp 76:7192 Singh AK, Mondal GC, Kumar S, Singh TB, Tewary BK, Sinha A (2008) Major io... more ... J Geo Exp 76:7192 Singh AK, Mondal GC, Kumar S, Singh TB, Tewary BK, Sinha A (2008) Major ion chemistry, weathering processes and water quality assessment in upper catchement of Damoda River basin, India. ...
GIS and Geostatistical Techniques for Groundwater Science, 2019
Abstract The suitability of groundwater for drinking and irrigation purposes was evaluated using ... more Abstract The suitability of groundwater for drinking and irrigation purposes was evaluated using Water Quality Index, GIS and Multivariate Statistical method in a part of Nalgonda District, Telangana, India Forty-five groundwater samples were collected from wells on January, 2010. On-site field measurements of pH, electrical conductivity (EC), and temperature, and the laboratory analysis of major ions were carried out. Six groundwater types are dominant: Ca-HCO3, Na-Cl, mixed Ca-Na-HCO3, mixed Ca-Mg-Cl, Ca-Cl, and Na-HCO3. Spatial variation maps were developed for physicochemical parameters by using inverse distance weighted interpolation method and grouping analysis. These maps are categorized as desirable, permissible, and not permissible according to the World Health Organization (WHO) standard. The water-quality index map comprised a 443 km2 area categorized as good for drinking purposes. Groundwater is suitable for irrigation by SAR, EC, Na%, PI, RSC, MR, and USSL classification and Wilcox methods. Multivariate statistical techniques of correlation matrix, factor analysis, and cluster analysis evaluated the hydrochemical variations and the driving factors as well as the hydrogeochemical characteristics of the aquifer. The final section of this study concludes that groundwater quality is mainly affected by water-rock interactions, intensive agricultural activities, and the anthropogenic activity in the study area.
Environmental Science and Pollution Research, 2020
resumen Este artículo explora las posibilidades y limitaciones del posneoliberalismo bajo las con... more resumen Este artículo explora las posibilidades y limitaciones del posneoliberalismo bajo las condiciones de la urbanización planetaria. Conceptualiza la urbanización planetaria como la tendencia hacia la subsunción real del espacio al capital en una escala global, a través de la cual el capital se fortalece como una forma abstracta de dominación. Critica la agenda neoestructuralista de «competitividad sistémica» y su influencia en el proyecto posneoliberal en América Latina, argumentando que se tiende a fortalecer el capital como sujeto. Se enfoca en la urbanización de la Amazonía ecuatoriana, desagregamos la subsunción real del espacio en tres dimensiones: territorio, naturaleza y vida cotidiana. palabras clave Posneoliberalismo, Amazonía ecuatoriana, urbanización, capital.
Desalination and Water Treatment, 2015
ABSTRACT
Water Quality, Exposure and Health, 2015
Suitability of groundwater for domestic and irrigation purposes as well as its hydrochemical char... more Suitability of groundwater for domestic and irrigation purposes as well as its hydrochemical characteristics was estimated in a part of Nalgonda district, Telangana state in southern India. Water samples were collected from 45 wells once every 2 months from March 2008 to January 2010. EC and pH were measured in situ while concentrations of calcium, magnesium, sodium, potassium, sulphate and chloride in groundwater were analysed using ion chromatograph. Carbonate and bicarbonate concentration were determined by acid base titration. General order of dominance of cations in the groundwater of this study area is Na+ > Ca2+ > Mg2+ > K+ while that for anions is HCO3− > Cl− > SO4−2. Ca–HCO3, Na–Cl, mixed Ca–Na–HCO3 and mixed Ca–Mg–Cl types of groundwater were dominant in this area. Groundwater is generally fresh with medium to high salinity and low alkalinity. Chloride and bicarbonate concentrations were present within the permissible limits for drinking whereas, some samples exceed the permissible limits of the Bureau of Indian Standards for pH, TDS, TH, sodium, calcium, magnesium and sulphate. Potassium exceeded the maximum permissible limits for drinking proposed by World Health Organisation. Sodium adsorption ratio, sodium percentage, residual sodium carbonate and permeability index indicates that the groundwater quality was suitable for irrigation in most parts of the study area.
Journal of environmental science & engineering, 2012
Intake of water with high concentration of nitrate is a major problem in many countries as it aff... more Intake of water with high concentration of nitrate is a major problem in many countries as it affects health of humans. The present study was carried out with the objective of determining the causes for higher nitrate concentration in groundwater in parts of Nalgonda district, Andhra Pradesh, India. The study area is located at a distance of about 135 km towards ESE direction from Hyderabad. Nitrate concentration in groundwater of this area was analysed by collecting groundwater samples from 46 representative wells. Samples were collected once in two months from March 2008 to January 2009. The nitrate concentration was analysed in the laboratory using Metrohm 861 advanced compact ion chromatograph using appropriate standards. The highest concentration recorded during the sampling period was 879.65 mg/L and the lowest concentration was below detection limit. Taking into consideration 45 mg/L of nitrate as the maximum permissible limit for drinking water set by BIS, it was found that ...
Environmental Monitoring and Assessment, 2014
Journal of the Indian Society of Remote Sensing, 2014
Environmental Monitoring and Assessment, 2010
Serious problems are faced in several parts of the world due to the presence of high concentratio... more Serious problems are faced in several parts of the world due to the presence of high concentration of fluoride in drinking water which causes dental and skeletal fluorosis to humans. Nalgonda district in Andhra Pradesh, India is one such region where high concentration of fluoride is present in groundwater. Since there are no major studies in the recent past, the present study was carried out to understand the present status of groundwater quality in Nalgonda and also to assess the possible causes for high concentration of fluoride in groundwater. Samples from 45 wells were collected once every 2 months and analyzed for fluoride concentration using an ion chromatograph. The fluoride concentration in groundwater of this region ranged from 0.1 to 8.8 mg/l with a mean of 1.3 mg/l. About 52% of the samples collected were suitable for human consumption. However, 18% of the samples were having less than the required limit of 0.6 mg/l, and 30% of the samples possessed high concentration of fluoride, i.e., above 1.5 mg/l. Weathering of rocks and evaporation of groundwater are responsible for high fluoride concentration in groundwater of
annauniv.academia.edu, 2010
Groundwater forms the major source of drinking water in the rural areas of most of the developing... more Groundwater forms the major source of drinking water in the rural areas of most of the developing nations of the world. Presence of high concentration of fluoride and nitrate in groundwater is a major problem in many countries as it causes health related problems. The present ...
<p>... more <p>Groundwater is a vital source of freshwater, an estimated 39% of all freshwater withdrawals in India are from groundwater. However, groundwater is a finite resource, and there is evidence that aquifers in Peninsular India are being depleted faster than they can recharge. This imbalance is likely to get worse in the future with the effects of a changing climate and increasing population.</p><p>It is clear that an accurate assessment of groundwater availability, now and in the future, is essential, but this is a challenge. High spatial variability coupled with the difficulty in measuring aquifer properties make it difficult to model groundwater at a basin scale. To address this, the representation of groundwater within the Global Water AVailability Assessment (GWAVA) model has been developed to provide greater insight into groundwater resources as part of an integrated water availability assessment in the Cauvery basin (81,000 km<sup>2</sup>) in Peninsula India.</p><p>For this assessment, the GWAVA model was adapted to include an improved groundwater representation, along with the effect of small-scale human interventions intended to artificially recharge groundwater. The model was calibrated against streamflow and groundwater levels across the basin. Model runs were executed for a baseline period and for future decades, using relevant combinations of CMIP5 climate (RCP) and shared socio-economic pathways (SSP) scenarios.</p><p>Over the baseline period (1986-2005), groundwater abstraction exceeded net aquifer recharge over 66% of the area of the basin. In the future (2061-2080), this was predicted to increase to 71% under the “worst-case” scenario (RCP 8.5, SSP 3) and 93% under the “best-case” scenario (RCP 4.5, SSP 1). This supports the existing evidence that groundwater resources are currently overexploited in the Cauvery basin and suggests that this situation will get worse in the future.</p><p>An additional output of this study has been to identify gaps in the data necessary for groundwater modelling (e.g. characteristics of aquifers, density of interventions, time series of aquifer levels and groundwater pumping), in terms of data availability and confidence. This knowledge can be used to inform future data collection to maximise the usefulness of future observations.</p><p>This method can be applied to other regions with a high dependency on groundwater, such as sub-Saharan Africa, for integrate water-resource assessments. It could also be extended in the future to include a water-quality component in the groundwater processes.</p>
Environmental Science and Pollution Research , 2020
This study is to assess the hydrogeochemical characteristics of groundwater at the deltaic region... more This study is to assess the hydrogeochemical characteristics of groundwater at the deltaic region of the Nakdong River Basin in the Busan Metropolitan City of Korea. The study area is covered by the Quaternary sedimentary deposits and the Cretaceous granites associated with unconformity. The thick sedimentary deposits consists of two aquifers, i.e., unconfined and confined aquifers on the basis of clay deposit. Groundwater samples were collected from seven boreholes: two from unconfined aquifer and five from confined aquifer systems during the wet season of 2017 year. ORP and DO indicates that the groundwater of the unconfined aquifer exists in the oxidization condition and that of the confined aquifer pertains in the reduction condition. Piper's trilinear diagram shows CaSO 4 type for groundwater of the unconfined aquifer, and NaCl type for that of the confined aquifer. Ionic concentrations of groundwater increase in the confined aquifer because of direct and reverse ion exchange processes. Carbonate weathering and evaporation are other mechanisms in the water-rock interaction. Saturation indices of dolomite and calcite are observed as oversaturated, while halite reveals undersaturation. Hierarchical cluster analysis (HCA) exhibits that cluster 1 and cluster 2 represents the properties of groundwater in unconfined and confined aquifers, respectively. Factor analysis shows that groundwater of the confined aquifer is much influenced by seawater, and includes heavy metals of iron and aluminum. Groundwater samples in unconfined and confined aquifers are located at the rock weathering and evaporation zones in the Gibbs diagram. Inverse geochemical modeling of PHREEQC code suggests that carbonate dissolution and ion exchange of major ions are the prevailing geochemical processes. This comprehensive research provides the distinguished hydrogeochemical characteristics of groundwater in confined and unconfined aquifer systems of the Nakdong River Basin in Busan City, Korea.
Suitability of groundwater for domestic and irrigation purposes as well as its hydrochemical char... more Suitability of groundwater for domestic and irrigation purposes as well as its hydrochemical characteristics was estimated in a part of Nalgonda district, Telangana state in southern India. Water samples were collected from 45 wells once every 2 months from March 2008 to January 2010. EC and pH were measured in situ while concentrations of calcium, magnesium, sodium, potassium, sulphate and chloride in groundwater were analysed using ion chromatograph. Carbonate and bicarbonate concentration were determined by acid base titration. General order of dominance of cations in the groundwater of this study area is Na+ > Ca2+ > Mg2+ > K+ while that for anions is HCO3 − > Cl− > SO 4 −2 . Ca–HCO3, Na–Cl, mixed Ca–Na–HCO3 and mixed Ca–Mg–Cl types of groundwater were dominant in this area. Groundwater is generally fresh with medium to high salinity and low alkalinity. Chloride and bicarbonate concentrations were present within the permissible limits for drinking whereas, some samples exceed the permissible limits of the Bureau of Indian Standards for pH, TDS, TH, sodium, calcium, magnesium and sulphate. Potassium exceeded the maximum permissible limits for drinking proposed by World Health Organisation. Sodium adsorption ratio, sodium percentage, residual sodium carbonate and permeability index indicates that the groundwater quality was suitable for irrigation in most parts of the study area.
Environmental Monitoring and Assessment, 2025
Groundwater is often used directly by the public in several river basins of India. Hence, this st... more Groundwater is often used directly by the public in several river basins of India. Hence, this study was carried out with the objective of assessing the quality of groundwater in the Amaravathi basin, India, using a multiple indices approach. Groundwater quality data from 96 monitoring wells were obtained from the Central Groundwater Board and used in this study. Drinking water quality index (DWQI) and irrigation water quality index (IWQI) were calculated to assess the water suitability for consumption, irrigation, and farming. High levels of fluoride and nitrate have a detrimental impact on health and were evaluated using USEPA methods by calculating the chronic daily intake and hazards quotient. Findings revealed that 42% of samples did not meet the DWQI standards due to high salinity, hardness, nitrate, and fluoride levels. Health risk assessment (HRA) of hazard quotients of nitrate are 81%, 61%, and 39% of samples, while those of fluoride are 85%, 68%, and 18% of samples for infants, children, and adults, respectively are unfit. High salinity rendered 35% of the sample unsuitable for irrigation, though most remained suitable for livestock. Spatial analysis revealed declining groundwater quality from the center to the east of the basin. This mapping study identified areas where the groundwater quality is inappropriate for the intended purpose and alternate water sources should be made viable.
The Earth's apparent resistivity is related to various parameters such as the mineral and fluid c... more The Earth's apparent resistivity is related to various parameters such as the mineral and fluid content, porosity and water saturation in the rock and soil. As most of the soil and rock-forming minerals are non-conductive, measuring the electrical apparent resistivity helps to delineate the porosity and the water content of a rock or soil system. Thus the electrical resistivity measurements provide the means to investigate the subsurface lithology and hydrological conditions of a region. The Vertical Electrical Sounding (VES) method is commonly used for the evaluation of subsurface geology and hydrogeology. In this study was carried out with the objective of using VES to assess the geological conditions of a proposed uranium mine tailings pond. Twenty six VES was carried out in the Seripalli area of Nalgonda District, Andhra Pradesh, India, where it is porposed to locate the uranium tailings pond. The interpretation of the results of VES indicate the presence of three layers. The first layer resistivity characteristics are those of sand and sandy clay with a thickness ranging from 0.5m to 3m. The next layer(weathered granite) with a thickness ranging from 1.3m to 12m and the lower most layer (fractured or massive granite) with a thickness ranging from 12.4m to 54m. Interpretation made was validated with a bore hole log of this area. The top soil constitutes the unsaturated zone with a apparent resistivity range from 0.57 to 452 ohm-m. The apparent resistivity ranges from 3.5 to 297.52 ohm-m in the weathered granite zone (upper aquifer zone) and from 300 to 3400 ohm-m for in the fractured or massive granite. Further work requires the characterization of the fracture system in the granite basement, because fractures may represent preferential pathways for the movements of the pollutants from the tailings disposal area.
The Earth’s apparent resistivity is related to various parameters such as the mineral and fluid c... more The Earth’s apparent resistivity is related to various parameters such as the mineral and fluid content, porosity and water saturation in the rock and soil. As most of the soil and rock-forming minerals are non-conductive, measuring the electrical apparent resistivity helps to delineate the porosity and the water content of a rock or soil system. Thus the electrical resistivity measurements provide the means to investigate the subsurface lithology and hydrological conditions of a region. The Vertical Electrical Sounding (VES) method is commonly used for the evaluation of subsurface geology and hydrogeology. In this study was carried out with the objective of using VES to assess the geological conditions of a proposed uranium mine tailings pond. Twenty six VES was carried out in the Seripalli area of Nalgonda District, Andhra Pradesh, India, where it is porposed to locate the uranium tailings pond. The interpretation of the results of VES indicate the presence of three layers. The fi...
GIS and Geostatistical Techniques for Groundwater Science, 2019
Unsupervised text attribute transfer automatically transforms a text to alter a specific attribut... more Unsupervised text attribute transfer automatically transforms a text to alter a specific attribute (e.g. sentiment) without using any parallel data, while simultaneously preserving its attribute-independent content. The dominant approaches are trying to model the content-independent attribute separately, e.g., learning different attributes' representations or using multiple attribute-specific decoders. However, it may lead to inflexibility from the perspective of controlling the degree of transfer or transferring over multiple aspects at the same time. To address the above problems, we propose a more flexible unsupervised text attribute transfer framework which replaces the process of modeling attribute with minimal editing of latent representations based on an attribute classifier. Specifically, we first propose a Transformer-based autoencoder to learn an entangled latent representation for a discrete text, then we transform the attribute transfer task to an optimization problem and propose the Fast-Gradient-Iterative-Modification algorithm to edit the latent representation until conforming to the target attribute. Extensive experimental results demonstrate that our model achieves very competitive performance on three public data sets. Furthermore, we also show that our model can not only control the degree of transfer freely but also allow transferring over multiple aspects at the same time. 1
Environmental science and pollution research international, Jan 18, 2015
This research aimed at developing comprehensive assessments of physicochemical quality of groundw... more This research aimed at developing comprehensive assessments of physicochemical quality of groundwater for drinking and irrigation purposes at Dalcheon in Ulsan City, Korea. The mean concentration of major ions represented as follows: Ca (94.3 mg/L) > Mg (41.7 mg/L) > Na (19.2 mg/L) > K (3.2 mg/L) for cations and SO4 (351 mg/L) > HCO3 (169 mg/L) > Cl (19 mg/L) for anions. Thematic maps for physicochemical parameters of groundwater were prepared, classified, weighted, and integrated in GIS method with fuzzy logic. The maps exhibited that suitable zone of drinking and irrigation purpose occupied in SE, NE, and NW sectors. The undesirable zone of drinking purpose was observed in SW and central parts and that of irrigation was in the western part of the study area. This was influenced by improperly treated effluents from an abandoned iron ore mine, irrigation, and domestic fields. By grouping analysis, groundwater types were classified into Ca(HCO3)2, (Ca,Mg)Cl2, and CaCl2...
Environmental Earth Sciences, 2011
... J Geo Exp 76:7192 Singh AK, Mondal GC, Kumar S, Singh TB, Tewary BK, Sinha A (2008) Major io... more ... J Geo Exp 76:7192 Singh AK, Mondal GC, Kumar S, Singh TB, Tewary BK, Sinha A (2008) Major ion chemistry, weathering processes and water quality assessment in upper catchement of Damoda River basin, India. ...
GIS and Geostatistical Techniques for Groundwater Science, 2019
Abstract The suitability of groundwater for drinking and irrigation purposes was evaluated using ... more Abstract The suitability of groundwater for drinking and irrigation purposes was evaluated using Water Quality Index, GIS and Multivariate Statistical method in a part of Nalgonda District, Telangana, India Forty-five groundwater samples were collected from wells on January, 2010. On-site field measurements of pH, electrical conductivity (EC), and temperature, and the laboratory analysis of major ions were carried out. Six groundwater types are dominant: Ca-HCO3, Na-Cl, mixed Ca-Na-HCO3, mixed Ca-Mg-Cl, Ca-Cl, and Na-HCO3. Spatial variation maps were developed for physicochemical parameters by using inverse distance weighted interpolation method and grouping analysis. These maps are categorized as desirable, permissible, and not permissible according to the World Health Organization (WHO) standard. The water-quality index map comprised a 443 km2 area categorized as good for drinking purposes. Groundwater is suitable for irrigation by SAR, EC, Na%, PI, RSC, MR, and USSL classification and Wilcox methods. Multivariate statistical techniques of correlation matrix, factor analysis, and cluster analysis evaluated the hydrochemical variations and the driving factors as well as the hydrogeochemical characteristics of the aquifer. The final section of this study concludes that groundwater quality is mainly affected by water-rock interactions, intensive agricultural activities, and the anthropogenic activity in the study area.
Environmental Science and Pollution Research, 2020
resumen Este artículo explora las posibilidades y limitaciones del posneoliberalismo bajo las con... more resumen Este artículo explora las posibilidades y limitaciones del posneoliberalismo bajo las condiciones de la urbanización planetaria. Conceptualiza la urbanización planetaria como la tendencia hacia la subsunción real del espacio al capital en una escala global, a través de la cual el capital se fortalece como una forma abstracta de dominación. Critica la agenda neoestructuralista de «competitividad sistémica» y su influencia en el proyecto posneoliberal en América Latina, argumentando que se tiende a fortalecer el capital como sujeto. Se enfoca en la urbanización de la Amazonía ecuatoriana, desagregamos la subsunción real del espacio en tres dimensiones: territorio, naturaleza y vida cotidiana. palabras clave Posneoliberalismo, Amazonía ecuatoriana, urbanización, capital.
Desalination and Water Treatment, 2015
ABSTRACT
Water Quality, Exposure and Health, 2015
Suitability of groundwater for domestic and irrigation purposes as well as its hydrochemical char... more Suitability of groundwater for domestic and irrigation purposes as well as its hydrochemical characteristics was estimated in a part of Nalgonda district, Telangana state in southern India. Water samples were collected from 45 wells once every 2 months from March 2008 to January 2010. EC and pH were measured in situ while concentrations of calcium, magnesium, sodium, potassium, sulphate and chloride in groundwater were analysed using ion chromatograph. Carbonate and bicarbonate concentration were determined by acid base titration. General order of dominance of cations in the groundwater of this study area is Na+ > Ca2+ > Mg2+ > K+ while that for anions is HCO3− > Cl− > SO4−2. Ca–HCO3, Na–Cl, mixed Ca–Na–HCO3 and mixed Ca–Mg–Cl types of groundwater were dominant in this area. Groundwater is generally fresh with medium to high salinity and low alkalinity. Chloride and bicarbonate concentrations were present within the permissible limits for drinking whereas, some samples exceed the permissible limits of the Bureau of Indian Standards for pH, TDS, TH, sodium, calcium, magnesium and sulphate. Potassium exceeded the maximum permissible limits for drinking proposed by World Health Organisation. Sodium adsorption ratio, sodium percentage, residual sodium carbonate and permeability index indicates that the groundwater quality was suitable for irrigation in most parts of the study area.
Journal of environmental science & engineering, 2012
Intake of water with high concentration of nitrate is a major problem in many countries as it aff... more Intake of water with high concentration of nitrate is a major problem in many countries as it affects health of humans. The present study was carried out with the objective of determining the causes for higher nitrate concentration in groundwater in parts of Nalgonda district, Andhra Pradesh, India. The study area is located at a distance of about 135 km towards ESE direction from Hyderabad. Nitrate concentration in groundwater of this area was analysed by collecting groundwater samples from 46 representative wells. Samples were collected once in two months from March 2008 to January 2009. The nitrate concentration was analysed in the laboratory using Metrohm 861 advanced compact ion chromatograph using appropriate standards. The highest concentration recorded during the sampling period was 879.65 mg/L and the lowest concentration was below detection limit. Taking into consideration 45 mg/L of nitrate as the maximum permissible limit for drinking water set by BIS, it was found that ...
Environmental Monitoring and Assessment, 2014
Journal of the Indian Society of Remote Sensing, 2014
Environmental Monitoring and Assessment, 2010
Serious problems are faced in several parts of the world due to the presence of high concentratio... more Serious problems are faced in several parts of the world due to the presence of high concentration of fluoride in drinking water which causes dental and skeletal fluorosis to humans. Nalgonda district in Andhra Pradesh, India is one such region where high concentration of fluoride is present in groundwater. Since there are no major studies in the recent past, the present study was carried out to understand the present status of groundwater quality in Nalgonda and also to assess the possible causes for high concentration of fluoride in groundwater. Samples from 45 wells were collected once every 2 months and analyzed for fluoride concentration using an ion chromatograph. The fluoride concentration in groundwater of this region ranged from 0.1 to 8.8 mg/l with a mean of 1.3 mg/l. About 52% of the samples collected were suitable for human consumption. However, 18% of the samples were having less than the required limit of 0.6 mg/l, and 30% of the samples possessed high concentration of fluoride, i.e., above 1.5 mg/l. Weathering of rocks and evaporation of groundwater are responsible for high fluoride concentration in groundwater of
annauniv.academia.edu, 2010
Groundwater forms the major source of drinking water in the rural areas of most of the developing... more Groundwater forms the major source of drinking water in the rural areas of most of the developing nations of the world. Presence of high concentration of fluoride and nitrate in groundwater is a major problem in many countries as it causes health related problems. The present ...
<p>... more <p>Groundwater is a vital source of freshwater, an estimated 39% of all freshwater withdrawals in India are from groundwater. However, groundwater is a finite resource, and there is evidence that aquifers in Peninsular India are being depleted faster than they can recharge. This imbalance is likely to get worse in the future with the effects of a changing climate and increasing population.</p><p>It is clear that an accurate assessment of groundwater availability, now and in the future, is essential, but this is a challenge. High spatial variability coupled with the difficulty in measuring aquifer properties make it difficult to model groundwater at a basin scale. To address this, the representation of groundwater within the Global Water AVailability Assessment (GWAVA) model has been developed to provide greater insight into groundwater resources as part of an integrated water availability assessment in the Cauvery basin (81,000 km<sup>2</sup>) in Peninsula India.</p><p>For this assessment, the GWAVA model was adapted to include an improved groundwater representation, along with the effect of small-scale human interventions intended to artificially recharge groundwater. The model was calibrated against streamflow and groundwater levels across the basin. Model runs were executed for a baseline period and for future decades, using relevant combinations of CMIP5 climate (RCP) and shared socio-economic pathways (SSP) scenarios.</p><p>Over the baseline period (1986-2005), groundwater abstraction exceeded net aquifer recharge over 66% of the area of the basin. In the future (2061-2080), this was predicted to increase to 71% under the “worst-case” scenario (RCP 8.5, SSP 3) and 93% under the “best-case” scenario (RCP 4.5, SSP 1). This supports the existing evidence that groundwater resources are currently overexploited in the Cauvery basin and suggests that this situation will get worse in the future.</p><p>An additional output of this study has been to identify gaps in the data necessary for groundwater modelling (e.g. characteristics of aquifers, density of interventions, time series of aquifer levels and groundwater pumping), in terms of data availability and confidence. This knowledge can be used to inform future data collection to maximise the usefulness of future observations.</p><p>This method can be applied to other regions with a high dependency on groundwater, such as sub-Saharan Africa, for integrate water-resource assessments. It could also be extended in the future to include a water-quality component in the groundwater processes.</p>
Environmental Science and Pollution Research , 2020
This study is to assess the hydrogeochemical characteristics of groundwater at the deltaic region... more This study is to assess the hydrogeochemical characteristics of groundwater at the deltaic region of the Nakdong River Basin in the Busan Metropolitan City of Korea. The study area is covered by the Quaternary sedimentary deposits and the Cretaceous granites associated with unconformity. The thick sedimentary deposits consists of two aquifers, i.e., unconfined and confined aquifers on the basis of clay deposit. Groundwater samples were collected from seven boreholes: two from unconfined aquifer and five from confined aquifer systems during the wet season of 2017 year. ORP and DO indicates that the groundwater of the unconfined aquifer exists in the oxidization condition and that of the confined aquifer pertains in the reduction condition. Piper's trilinear diagram shows CaSO 4 type for groundwater of the unconfined aquifer, and NaCl type for that of the confined aquifer. Ionic concentrations of groundwater increase in the confined aquifer because of direct and reverse ion exchange processes. Carbonate weathering and evaporation are other mechanisms in the water-rock interaction. Saturation indices of dolomite and calcite are observed as oversaturated, while halite reveals undersaturation. Hierarchical cluster analysis (HCA) exhibits that cluster 1 and cluster 2 represents the properties of groundwater in unconfined and confined aquifers, respectively. Factor analysis shows that groundwater of the confined aquifer is much influenced by seawater, and includes heavy metals of iron and aluminum. Groundwater samples in unconfined and confined aquifers are located at the rock weathering and evaporation zones in the Gibbs diagram. Inverse geochemical modeling of PHREEQC code suggests that carbonate dissolution and ion exchange of major ions are the prevailing geochemical processes. This comprehensive research provides the distinguished hydrogeochemical characteristics of groundwater in confined and unconfined aquifer systems of the Nakdong River Basin in Busan City, Korea.
Suitability of groundwater for domestic and irrigation purposes as well as its hydrochemical char... more Suitability of groundwater for domestic and irrigation purposes as well as its hydrochemical characteristics was estimated in a part of Nalgonda district, Telangana state in southern India. Water samples were collected from 45 wells once every 2 months from March 2008 to January 2010. EC and pH were measured in situ while concentrations of calcium, magnesium, sodium, potassium, sulphate and chloride in groundwater were analysed using ion chromatograph. Carbonate and bicarbonate concentration were determined by acid base titration. General order of dominance of cations in the groundwater of this study area is Na+ > Ca2+ > Mg2+ > K+ while that for anions is HCO3 − > Cl− > SO 4 −2 . Ca–HCO3, Na–Cl, mixed Ca–Na–HCO3 and mixed Ca–Mg–Cl types of groundwater were dominant in this area. Groundwater is generally fresh with medium to high salinity and low alkalinity. Chloride and bicarbonate concentrations were present within the permissible limits for drinking whereas, some samples exceed the permissible limits of the Bureau of Indian Standards for pH, TDS, TH, sodium, calcium, magnesium and sulphate. Potassium exceeded the maximum permissible limits for drinking proposed by World Health Organisation. Sodium adsorption ratio, sodium percentage, residual sodium carbonate and permeability index indicates that the groundwater quality was suitable for irrigation in most parts of the study area.
Elsevier, 2019
Heavy metals in trace concentrations have the most important function in the metabolism and healt... more Heavy metals in trace concentrations have the most important function in the metabolism and healthy growth of plants and animals. However, if the concentration is increased it may have several toxicological effects on human beings. Two processes comprise the main sources of heavy metals: natural and anthropogenic. The natural source involves the release of metals as a result of rock weathering and their ultimate leaching into groundwater through rock-water interactions. The anthropogenic sources are the discharge of heavy metals through mining, construction and industrial activities, which thereafter enter streams around mines, the pulverization of construction materials discharge of industrial effluents and landfill leachate into groundwater and surface water bodies; and other activities (Handa et al., 1981; Leung and Jiao, 2006). Water-quality indices are helpful in estimating the combined effect of different parameters. Water-contamination indices are practical and comparatively simple approaches for evaluating the influence and source of overall contamination. The contamination indices are calculated to give useful and approachable guiding tools for water-quality administrators, environmental managers, decision-makers, and prospective users of a prospective water system. Specific contamination indices have also been used to evaluate the extent of contamination with respect to certain metals (Prasad and Jaiprakas, 1999; Prasad and Bose, 2001). Statistical methods, particularly multivariate techniques, are adequate to resolve this lack of contamination indices, and are helpful for environmental data reduction and the interpretation of multiple parameters. Principal component analysis (PCA) and correlation matrix (CM) are widely used in water-quality assessment and monitoring (Venkatramanan et al., 2015; Bhuiyanet al., 2010). PCA and CM help to arrange metals or analyzed parameters into different factors/groups on the basis of contribution from the expected source. Depending on the co-variance of the analyzed parameters, the multivariate technique is able to provide useful information on the origin of groundwater contamination. The hydrogeochemical species of an element is important regarding its environmental chemistry. The GIS and Geostatistical Techniques for Groundwater Science. https://doi.