Fluoride Removal from Water by Adsorption on a High Alumina Content Bauxite

Abstract

Drinking water contamination by fluoride is recognized as a major public health problem in many parts of the world. In fact, although fluoride is an essential trace element for animals and humans, excessive fluoride intake may cause adverse health effects. In this study we investigated the potential of a natural, high alumina content, bauxite for the removal of fluoride from contaminated water. Both batch and continuous experiments were performed. In continuous-flow column experiments, the effects of inlet fluoride concentration (5–50 mg L–1) and flowrate (up to 2.5 mL min–1) on breakthrough time and adsorption capacity were studied. Batch equilibrium data were found to be well described by the Freundlich equation. Column studies showed that the dynamic adsorption capacity of the bed decreased as the inlet fluoride concentration and the flow rate increased. A maximum fluoride uptake capacity of 3.125 mg g–1 was determined. Overall, the results obtained indicate that this bauxite could be effectively used for defluoridation of drinking water.