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Defluoridation from aqueous solutions by nano-alumina: characterization and sorption studies.

Research paper by Eva E Kumar, Amit A Bhatnagar, Umesh U Kumar, Mika M Sillanpää

Indexed on: 24 Dec '10Published on: 24 Dec '10Published in: Journal of Hazardous Materials



Abstract

The present study was conducted to evaluate the feasibility of nano-alumina (Al(2)O(3)) 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°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 PO(4)(3-), SO(4)(2-) and CO(3)(2-) ions.