Hydrogeochemical evaluation of high-fluoride groundwaters: a case study from Mehsana District, Gujarat, India

Abstract

Groundwater quality problems have emerged in many geographical areas due to natural environmental processes and human intervention in the geosystems. Hydrogeochemical appraisal of fluoride contaminated groundwater in Mehsana District, Gujarat State, India is carried out by means of groundwater quality investigations together with X-ray diffraction analysis of soil samples in the delineated high fluoride areas. Results show that fluoride has negative relationships with calcium, whereas relationships with sodium, alkalinity and sulphate are positive. Results obtained from aqueous speciation modelling using PHREEQC reveal that the groundwater is undersaturated with fluorite and oversaturated with calcite. The factor analysis indicates that sodium plus potassium bicarbonate groundwater have high factor loading for fluoride, whereas that for calcium chloride and magnesium chloride groundwater is low. The plausible geochemical reactions in the study area are precipitation of calcite and dissolution of dolomite, carbon dioxide and sulphate minerals with ion exchange.

Fluoride in Drinking Water: Health Effects and Remediation

“…It has been reported that once the solubility limit for fluorite (CaF 2 ) is reached, an inverse relationship will exist between fluoride and calcium concentrations (Ozsvath 2009). Many studies have found a strong association between high fluoride and soft, alkaline (i.e., sodium-bicarbonate) groundwater that is depleted in calcium (Bårdsen et al 1996;Chae et al 2006aChae et al , 2007Conrad et al 1999;Dhiman and Keshari 2006;Earle and Krogh 2004;Gupta et al 1999;Handa 1975;IGRAC 2003a;Kohut et al 2001;Pekdeger et al 1992;Robertson 1986;Whittemore et al 1993). Other than these, pH and the development of secondary minerals are responsible in high mobility of fluoride in soil (Jacks et al 2005).…”

Study of Groundwater Salinity in Few Districts Adjoining River Ganga in Uttar Pradesh - A Case Study

“…13). On the other hand, once the solubility limit of fluorite (CaF 2 ) is reached, an inverse relationship appears between F -and Ca 2+ concentrations, and many studies have been found a strong association between high F -and soft, Alkaline (i.e., NaHCO 3 ) groundwater with depleted Calcium (Bardsen et al, 1996;Conrad et al, 1999;Gupta et al, 1999;Earle and Krogh, 2004;Chae et al, 2006a;Dhiman and Keshari, 2006;Chae et al, 2007). It appears although that the solubility of fluorite (CaF 2 ) might have reached maximum in Uttar Pradesh aquifers.…”

Hydrogeochemical processes controlling the high fluoride concentration in groundwater: a case study at the Boden block area, Orissa, India

“…1 Alkaline earths exceed alkali metals, 2 alkali metals exceed alkaline earths, 3 weak acidic anions exceed strong acidic anions, 4 strong acidic anions exceed weak acidic anions, 5 alkaline earths and weak acidic anions exceed both alkali metals and strong acidic anions, 6 alkaline earths exceed alkali metals and strong acidic anions exceed weak acidic anions, 7 alkali metals exceed alkaline earths and strong acidic anions exceed weak acidic anions, and 8 alkali metals exceed alkaline earths and weak acidic anions exceed strong acidic anions which is 5.95 is due to the ion exchange between Na adsorbed on the surface of the clay minerals and Ca in the groundwater (Guo and Wang 2005). A number of other studies have also reported a strong association between high fluoride and soft alkaline groundwater depleted in calcium content (Chae et al 2006(Chae et al , 2007Dhiman and Keshari 2006).…”