Entrapment of powdered drinking water treatment residues in calcium-alginate beads for fluoride removal from actual industrial wastewater

Abstract

The present study describes the preparation of drinking water treatment residues (DWTRs) based adsorptive media (DREAM) by entrapping the powdered-DWTRs in calcium-alginate beads and their application to fluoride removal from actual industrial wastewater. In order to evaluate the fluoride adsorption capability and mechanisms of DREAM, the adsorption equilibrium isotherm, kinetics, and effect of solution pH on fluoride removal by DREAM were evaluated. The batch and fixed-bed column adsorption tests confirmed that DREAM had high selectivity for adsorbing fluoride from actual industrial wastewater, which contained other co-existing anions (e.g., nitrate, chloride, and sulfate).