Sorption of fluoride ions from aqueous solutions and well drinking water by thermally treated hydrotalcite

Fluoride is a naturally occurring element in many water supplies, and it may cause fluorosis. The hydrotalcite was synthesized and characterized before and after the retention of fluoride ions by x-ray diffraction, electron microscopy, and IR. The thermally treated hydrotalcite was evaluated for the sorption of fluoride ions from aqueous solutions at pH 5, 7, and 9 and well water. It was found that the retention of fluoride ions by the material was 80% or higher. The Kd values show that the best conditions for the sorption of F- ions from the solutions is at pH 5, and they show as well that the physicochemical properties affect the uptake process.