Research Article
S. Gupta, D. Mondal, A. Bardha
Abstract
Present research work undertakes the hydro-geochemical characterization as well as demarcation of fluoride (F-) contaminated area by means of GIS modeling. F- concentration in the study area ranges from 0.20 mg/l to 1.67 mg/l with a mean of 0.72 mg/l. Among the twenty six (26) collected samples from water table sedimentary aquifer of study area 54% samples have F- concentration <0.6 mg/l; and 8% of the samples have concentration >1.5 thereby unsuitable for drinking purpose. Majority of the water samples fall under the category of Ca-Mg-Cl followed by Ca-HCO3 type hydrofacies. Fluoride has a significant (p<.05) positive correlation with bicarbonate (HCO3 -) ion and it also shows a positive correlation with sodium (Na+) but higher negative correlation with calcium (Ca2+). This may be attributed to ion-exchange process where Ca2+ ions in water may react with clay minerals (sodiummontmorillonite) to release Na+ ion in groundwater. All the groundwater samples have Ca2+<