Flúor en aguas de ríos de las sierras de Córdoba, Argentina.

GARCÍA, M.G.; LECOMTE, K.L.; MARTÍNEZ, J.O.; FORMICA, S.M.; DEPETRIS, P.J.

Córdoba Capital

Congreso; I Congreso Internacional sobre gestión y tratamiento integral del agua.; 2006

Abstract                 We are analyzing the concentrations of F- in the upper catchments of rivers draining granitic terrains in the Sierras de Córdoba. Concentrations range between 0.21 mg L-1 and 2.74 mg L-1, exceeding in several cases the guideline for drinking water quality. 65% of samples show intermediate contents of F- (0,5 to 1,0 mg L-1), 10% show low concentrations (< 0,5 mg L-1) and the remaining 25% show concentrations higher than 1,0 mg L-1.                 The likely sources of F- are the granitoid rocks that outcrop in the highest ranges of the Sierras de Córdoba. Chemical data suggests that the weathering of fluorapatite and biotite are probably the main cause of F- in the water. The downflow variation of F- concentrations is mainly controlled by water pH and river discharges, as the fluorite supersaturation is never reached. Under acidic to neutral pH, the concentration of F- is lower as its affinity for Fe and Al (hydr)oxide surfaces increases.