RAJA V
@tec-edu.in
Assistant Professor
Assistant Professor
EDUCATION
Doctor of Philosophy in Chemistry
RESEARCH, TEACHING, or OTHER INTERESTS
Chemistry, Environmental Chemistry, Water Science and Technology, Pollution
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
V Raja and M A Neelakantan
Springer Science and Business Media LLC
Velayutham Raja and Mallanpillai Anthakrishnan Neelakantan
Informa UK Limited
ABSTRACT Pollution level and noncarcinogenic health risks due to fluoride and nitrate in the groundwater samples from Ramanathapuram district during pre-monsoon (September 2016) were calculated. One hundred and fifty-two groundwater samples collected were analysed for various physicochemical parameters such as major cations (Ca2+, Mg2+, Na+, K+) and major anions (CO3 2-, HCO3 −, SO4 2-, Cl−, NO3 −, PO4 3-). The fluoride ion concentrations in the collected samples were measured using the fluoride ion-selective electrode. Noncarcinogenic risks were calculated based on fluoride and nitrate concentrations (fluoride – 0.02–1.00 and nitrate – 0.0–4.9). The calculated risk values exceed the United States Environmental Production Agency (USEPA) recommended value of 1. The habitants from the study area are under the health risk due to fluoride and nitrate. Water quality index (WQI) values of the analysed samples indicate that 52% poor, 14% very poor, and 4% unsuitable for drinking purposes. Piper plot shows that 58% of mixed Ca2+-Mg2+-Cl− and 16% of Na+-Cl− groundwater types are predominant in the study area. Gibbs plot reveals that 91% of the samples have rock-water interaction, and it is a principal process that controls the dissolution of minerals from the subsurface into groundwater. Statistical analysis (correlation analysis, factor analysis) reveals that the natural process (rock-water interaction, leaching of sediments) and anthropogenic activities (domestic sewage, untreated effluents from industries) are the reason for the high fluoride and nitrate concentration in the groundwater. High noncarcinogenic health risk places were marked in spatial distribution maps.
Velayutham Raja and Mallanpillai Ananthakrishnan Neelakantan
Informa UK Limited
Abstract The present investigation aims to determine the health risks of toxic uranium contamination in the drinking water of the Thoothukudi district. Two hundred and eighty-six samples were examined during the pre- and post-monsoon seasons and found the uranium concentration ranges from <0.2 to 167 ppb (mean 12, Standard deviation 21) (pre-monsoon) and <02 to 190 ppb (mean 13, Standard deviation 24) (post-monsoon). Geochemical modeling studies and the reducing nature of samples reveal that the uraninite mineral is under saturated conditions, and the least soluble U4O9 mineral species is predominantly distributed during both seasons. Statistical analysis provides that applying nitrogen and phosphate fertilizers may induce the dissolution of uranium minerals, which is responsible for elevated uranium in the collected samples. The calculated noncarcinogenic risk of uranium range from 0.005 to 8.09 (pre-monsoon) and 0.005 to 9.18 (post-monsoon). 15% (pre-monsoon) and 17% (post-monsoon) of the samples show a higher noncarcinogenic risk. The calculated cancer mortality and morbidity are within the permissible limit of 10−3, and the present health risk assessment of uranium is evident that the people from this district have the chemical toxicity of uranium than the carcinogenic risk due to drinking water.
Velayutham Raja and Mallanpillai Ananthakrishnan Neelakantan
Informa UK Limited
Abstract The present research aims to determine the sources and concentration of uranium in the groundwater of the hard rock aquifer. Two hundred and fifty-four groundwater samples were collected, and the analysis shows the uranium concentrations range from 0.5 to 113 ppb (pre-monsoon) and 0.5 to 120 ppb (post-monsoon). Factor analysis illustrates that the lower concentrations of uranium in the study region may be due to the poor dissolution of minerals in the subsurface. Saturation Index values confirm that the Uraninite mineral is undersaturated, and the U4O9 has dominant distribution during both seasons. During both seasons, four samples have a uranium concentration of more than 60 ppb, which might be due to the fertilizer usage in the agricultural activities in the study area. The GIS technique highlights the uranium-contaminated location and polluted water quality parameters using the Inverse Distance Weighted spatial interpolation plots.
Velayutham Raja and Mallanpillai A. Neelakantan
Informa UK Limited
Ramamoorthy Venkada Lakshmi, Velayutham Raja, Sabarathinam Chidambaram, Chelladurai Puthiya Sekar, and Mallanpillai Anthakrishnan Neelakantan
Springer Science and Business Media LLC
V. Raja, Sunil Kumar Sahoo, K. Sreekumar, and M. A. Neelakantan
Springer Science and Business Media LLC
R. Venkada Lakshmi, V. Raja, C. Puthiya Sekar, and M. A. Neelakantan
Springer Science and Business Media LLC
Velayutham Raja and Mallanpillai Anathakrishnan Neelakantan
Springer Science and Business Media LLC
Velayutham Raja, Ramamoorthy Venkada Lakshmi, Chelladurai Puthiya Sekar, Sabarathinam Chidambaram, and Mallanpillai Anathakrishnan Neelakantan
Springer Science and Business Media LLC
Durai Ganesh, G Senthil Kumar, Laith Ahmed Najam, V Raja, M A Neelakantan, and R Ravisankar
Oxford University Press (OUP)
Abstract The aim of this study is to assess the degree of contamination in drinking water sources around the holy mountain “Arunachala” in Tiruvannamalai, Tamil Nadu. Drinking water samples from 20 different sites were collected, and their physio-chemical parameters, pH, electrical conductivity and total dissolved solvents were determined. An LED fluorimeter was used to determine the concentration of uranium in these samples. As consumption of contaminated drinking water involves both carcinogenic and non-carcinogenic risk, excess cancer risk; life-time average daily dose; hazard quotient and annual effective dose were calculated for the samples. On comparing these values with their respective maximum permissible limits, it is found that water from the aquifers around the mountain is safe to consume.