Adsorptive removal of fluoride from drinking water using porous starch loaded with common metal ions

Abstract

In this study, porous corn starch was loaded with Zr, Al, Fe or La to produce the composites PS-Zr, PS-Al, PS-Fe and PS-La. Fluoride adsorption from water was tested at different biosorbent dosages, contact times, solution pH values and initial fluoride concentrations. The biosorbents were characterized by microscopy and spectroscopy. PS-Zr was shown superior defluoridation capacity over a pH range of 3.0-9.0. The adsorption process could be described by the Langmuir isotherm model and the Lagergren pseudo-second-order kinetic model. The maximum fluoride adsorption capacity calculated to be for PS-Zr was 25.41mg/g. Our results revealed that PS-Zr could be employed as an effective biosorbent for removal of fluoride from drinking water.

Keywords: Adsorption; Drinking water; Fluorine; Metal ions; Porous starch.