Singa Raja - Academia.edu (original) (raw)
Papers by Singa Raja
In the present study, radon concentrations were measured in 70 groundwater samples collected from... more In the present study, radon concentrations were
measured in 70 groundwater samples collected from Tuticorin
district of Tamil Nadu, India. Radon activity concentration
was found in the range of 0.07–40.70 Bq L-1
with an average value of 5.13 Bq L-1. Radon values were
compared with USEPA and WHO. In this study radon
activity trend is above the permissible limit may be due to
influence of heavy rainfall. A good correlation is found
with deeper borehole depth and lithology. Granitic terrain
is found to have higher radon concentration.
Dissolved oxygen content in a water column serves as an indicator of pollution and it indirectly ... more Dissolved oxygen content in a water column serves as an indicator of pollution and it indirectly indicates the geochemical nature of the water. An attempt has been made in this study to understand the behavior of Dissolved Oxygen (DO) in eleven open wells along the coast of Cuddalore District, Tamilnadu, South India. Observations were made in situ for DO and Electrical Conductivity (EC) depth wise for 24 hours during a full moon period of every two hours. The study indicates that a definite stratification exists in a certain location and mixing trends in some locations. It also shows that there are fluctuations of these values with time and it has a definite relation at specific location. The temporal and the spatial relationships between EC and DO were also used in an attempt to understand the coastal ecosystem in the natural environment.
A study was conducted to bring out the relationship and behavior of different Saturation Index (S... more A study was conducted to bring out the relationship and behavior of different Saturation Index (SI) of carbonate minerals in layered coastal aquifers. Carbonates present in groundwater aids in different nature of the water like hardness, partial pressure of carbon-di-oxide (pCO 2 ), pH and saturation index of different carbonate minerals at various temperatures. The SI of the carbonates helps us to define the thermodynamic stability of water and to find out the geochemical behavior of water. 98 groundwater samples were collected from specific aquifers (alluvium, upper Cuddalore, lower Cuddalore and Cretaceous) during Pre-Monsoon (May 2007) and Post-Monsoon (January 2008) seasons. The physicochemical parameters such as pH, EC, Ca, Mg, Na, K, Cl, HCO 3 , SO 4 and PO 4 were analyzed. Geochemical model, WATEQ4F was used to calculate the SI of different minerals. The SI was studied in relation to mHCO 3 concentration, pCO 2 and correlation between SI of different minerals.
Geochemical signatures of groundwater in the Pondicherry region, south India, were determined. Th... more Geochemical signatures of groundwater in the Pondicherry region, south India, were determined. The coastal aquifers are fragile and this situation becomes more intense in layered aquifer systems like that of the Pondicherry region. In this region, groundwater occurs in alluvium, Lower Cuddalore, Upper Cuddalore, Tertiary, Cretaceous and mixed aquifers. The geochemical signature of groundwater in these formations was studied by collecting 93 groundwater samples. The collected samples from specific formations were analysed for physical parameters, such as electrical conductivity (EC), pH and major ion concentrations, such as Ca, Mg, Na, K, Cl, HCO 3 , PO 4 and SO 4 . The results of the analysis were interpreted with geology; the ionic concentrations in the groundwater vary spatially and temporally. The abundance of these ions are in the following order: SO 4 . Interpretation of analytical data shows that Ca-Na and Cl-SO 4 -HCO 3 is the dominant facies in all the formations. Groundwater in the area is generally hard and fresh-brackish in most of the formations and brackish in nature in alluvium formation. The sodium absorption ratio shows that most of the samples are grouped under excellent category to good category in all the formations. The residual sodium carbonate also are in good category in all the formations. Chloro-alkaline indices reveal that the majority of samples show negative values in all the litho units indicating the exchange of Na and K in groundwater with Mg or Ca in rock. Scholler classification of water indicates that longer residence time of water with more prominent base exchange. High EC and TDS values in certain locations of alluvial, Upper Cuddalore and Cretaceous formations prove to be unsuitable for drinking and irrigation purposes.
The study of groundwater hydrogeochemistry of a hard rock aquifer system in Thoothukudi district ... more The study of groundwater hydrogeochemistry
of a hard rock aquifer system in Thoothukudi district has
resulted in a large geochemical data set. A total of 100
water samples representing various lithologies like Hornblende
Biotite Gneiss, Alluvium Marine, alluvium Fluvial,
Quartzite, Charnockite, Granite and Sandstone were collected
for two different seasons and analyzed for major
ions like Ca2?, Mg2
?, Na?, K?, HCO3
-, Cl-, SO42-,
NO3
-, PO4-, F- and H4SiO4. Statistical analysis of the
data has been attempted to unravel the hidden relationship
between ions. Correlation analyses and factor analyses
were applied to classify the groundwater samples and to
identify the geochemical processes controlling groundwater
geochemistry. Factor analysis indicates that sea water
intrusion followed by leaching of secondary salts, weathering
and anthropogenic impacts are the dominant factors
controlling hydrogeochemistry of groundwater in the study
area. Factor score overlay indicate major active hydrogeochemical
regimes are spread throughout the Eastern,
Northwestern and Southeastern parts of the study area. The
dominant ions controlling the groundwater chemistry irrespective
of season are Cl-, Na?, Mg2?, Ca2?, SO4
2-, K?
and NO3
-. An attempt has also been made to note the
seasonal variation of the factor representations in the study
area. This study also illustrates the usefulness of statistical analysis to improve the understanding of groundwater
systems and estimates of the extent of salinity/salt water
intrusion.
In the present study, radon concentrations were measured in 70 groundwater samples collected from... more In the present study, radon concentrations were
measured in 70 groundwater samples collected from Tuticorin
district of Tamil Nadu, India. Radon activity concentration
was found in the range of 0.07–40.70 Bq L-1
with an average value of 5.13 Bq L-1. Radon values were
compared with USEPA and WHO. In this study radon
activity trend is above the permissible limit may be due to
influence of heavy rainfall. A good correlation is found
with deeper borehole depth and lithology. Granitic terrain
is found to have higher radon concentration.
Dissolved oxygen content in a water column serves as an indicator of pollution and it indirectly ... more Dissolved oxygen content in a water column serves as an indicator of pollution and it indirectly indicates the geochemical nature of the water. An attempt has been made in this study to understand the behavior of Dissolved Oxygen (DO) in eleven open wells along the coast of Cuddalore District, Tamilnadu, South India. Observations were made in situ for DO and Electrical Conductivity (EC) depth wise for 24 hours during a full moon period of every two hours. The study indicates that a definite stratification exists in a certain location and mixing trends in some locations. It also shows that there are fluctuations of these values with time and it has a definite relation at specific location. The temporal and the spatial relationships between EC and DO were also used in an attempt to understand the coastal ecosystem in the natural environment.
A study was conducted to bring out the relationship and behavior of different Saturation Index (S... more A study was conducted to bring out the relationship and behavior of different Saturation Index (SI) of carbonate minerals in layered coastal aquifers. Carbonates present in groundwater aids in different nature of the water like hardness, partial pressure of carbon-di-oxide (pCO 2 ), pH and saturation index of different carbonate minerals at various temperatures. The SI of the carbonates helps us to define the thermodynamic stability of water and to find out the geochemical behavior of water. 98 groundwater samples were collected from specific aquifers (alluvium, upper Cuddalore, lower Cuddalore and Cretaceous) during Pre-Monsoon (May 2007) and Post-Monsoon (January 2008) seasons. The physicochemical parameters such as pH, EC, Ca, Mg, Na, K, Cl, HCO 3 , SO 4 and PO 4 were analyzed. Geochemical model, WATEQ4F was used to calculate the SI of different minerals. The SI was studied in relation to mHCO 3 concentration, pCO 2 and correlation between SI of different minerals.
Geochemical signatures of groundwater in the Pondicherry region, south India, were determined. Th... more Geochemical signatures of groundwater in the Pondicherry region, south India, were determined. The coastal aquifers are fragile and this situation becomes more intense in layered aquifer systems like that of the Pondicherry region. In this region, groundwater occurs in alluvium, Lower Cuddalore, Upper Cuddalore, Tertiary, Cretaceous and mixed aquifers. The geochemical signature of groundwater in these formations was studied by collecting 93 groundwater samples. The collected samples from specific formations were analysed for physical parameters, such as electrical conductivity (EC), pH and major ion concentrations, such as Ca, Mg, Na, K, Cl, HCO 3 , PO 4 and SO 4 . The results of the analysis were interpreted with geology; the ionic concentrations in the groundwater vary spatially and temporally. The abundance of these ions are in the following order: SO 4 . Interpretation of analytical data shows that Ca-Na and Cl-SO 4 -HCO 3 is the dominant facies in all the formations. Groundwater in the area is generally hard and fresh-brackish in most of the formations and brackish in nature in alluvium formation. The sodium absorption ratio shows that most of the samples are grouped under excellent category to good category in all the formations. The residual sodium carbonate also are in good category in all the formations. Chloro-alkaline indices reveal that the majority of samples show negative values in all the litho units indicating the exchange of Na and K in groundwater with Mg or Ca in rock. Scholler classification of water indicates that longer residence time of water with more prominent base exchange. High EC and TDS values in certain locations of alluvial, Upper Cuddalore and Cretaceous formations prove to be unsuitable for drinking and irrigation purposes.
The study of groundwater hydrogeochemistry of a hard rock aquifer system in Thoothukudi district ... more The study of groundwater hydrogeochemistry
of a hard rock aquifer system in Thoothukudi district has
resulted in a large geochemical data set. A total of 100
water samples representing various lithologies like Hornblende
Biotite Gneiss, Alluvium Marine, alluvium Fluvial,
Quartzite, Charnockite, Granite and Sandstone were collected
for two different seasons and analyzed for major
ions like Ca2?, Mg2
?, Na?, K?, HCO3
-, Cl-, SO42-,
NO3
-, PO4-, F- and H4SiO4. Statistical analysis of the
data has been attempted to unravel the hidden relationship
between ions. Correlation analyses and factor analyses
were applied to classify the groundwater samples and to
identify the geochemical processes controlling groundwater
geochemistry. Factor analysis indicates that sea water
intrusion followed by leaching of secondary salts, weathering
and anthropogenic impacts are the dominant factors
controlling hydrogeochemistry of groundwater in the study
area. Factor score overlay indicate major active hydrogeochemical
regimes are spread throughout the Eastern,
Northwestern and Southeastern parts of the study area. The
dominant ions controlling the groundwater chemistry irrespective
of season are Cl-, Na?, Mg2?, Ca2?, SO4
2-, K?
and NO3
-. An attempt has also been made to note the
seasonal variation of the factor representations in the study
area. This study also illustrates the usefulness of statistical analysis to improve the understanding of groundwater
systems and estimates of the extent of salinity/salt water
intrusion.