Journal of Hazardous Materials, Vol.186, No.2-3, 1042-1049, 2011
Defluoridation from aqueous solutions by nano-alumina: Characterization and sorption studies
The present study was conducted to evaluate the feasibility of nano-alumina (Al2O3) for fluoride adsorption from aqueous solutions. The nature and morphology of pure and fluoride-sorbed nano-alumina were characterized by SEM with EDX, XRD, and FTIR analysis. Batch adsorption studies were performed as a function of contact time, initial fluoride concentration, temperature, pH and influence of competing anions. Fluoride sorption kinetics was well fitted by pseudo-second-order model. The maximum sorption capacity of nano-alumina for fluoride removal was found to be 14.0 mg g(-1) at 25 degrees C. Maximum fluoride removal occurred at pH 6.15. The fluoride sorption has been well explained using Langmuir isotherm model. Fluoride sorption was mainly influenced by the presence of PO43-, SO42- and CO32- ions. (C) 2010 Elsevier B.V. All rights reserved.