Fluoride removal from water by adsorption on acid activated kaolinite clay

Abstract

When drinking water contains excess fluoride it causes health hazards to human beings. In the present investigation the removal of fluoride has been attempted using acid activated kaolinite clay obtained from local traditional potter of Majuli river island, Assam. The clay was characterized by chemical analysis, IR, XRD data and thermal analysis. The clay was activated with conc. H₂SO₄. The fluoride removal studies were done by adsorption method on raw clay and acid activated clay. The effects of contact time, approximate particle size, pH and temperature were investigated. The adsorption followed Langmuir isotherm. The results show that acid activated kaolinite clay is effective for defluoridation of water while raw kaolinite has very low defluoridation capacity due to low adsorption.