Chemical properties of fluoride concentrators in groundwater(Case study: Qalandaraz region of Ahar city functions)

The concentration of fluoride in the groundwater of Qalandar region around Ahar city is in the range of 0.3 to 5.5 mg / l. For about 78% of the samples, it is higher than the standard range of 1.5 mg / l In this study, some of the chemical properties that control the concentration of fluoride in the groundwater of the region are examined. For this purpose, after collecting twenty samples of groundwater from wells drilled in villages located around Ahar city, the amounts of sodium, potassium, carbonate ions, Bicarbonate, chlorine and fluorine; pH; The ratio of sodium adsorption (SAR) and total soluble solids in water samples was measured in the laboratory. The findings showed The groundwater of this region is alkaline (pH-8.4-8 / 4 = pH) and saline (3500-449 mg / l = total soluble solids). This chemical property reflects the high rate of evaporation. Groundwater is also highly saturated with calcium, which helps to remove calcium and bicarbonate from the solution. High fluoride concentrations in the region showed high correlation with high pH, ​​total soluble solids and high sodium absorption ratio. This indicates high levels of fluoride as a result of the high solubility of fluoride minerals in the region due to calcium depletion and high ionic strength. The release of fluoride from colloidal surfaces under high pH conditions The results of these findings are shown in other studies.