title: Defluoridation from aqueous solutions by nano-alumina: characterization and sorption studies.
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.
authors.affiliation: Laboratory of Separation and Reaction Engineering, Departamento de Engenharia Química, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal.
authors.forename: Eva
authors.initials: E
authors.lastname: Kumar
authors.forename: Amit
authors.initials: A
authors.lastname: Bhatnagar
authors.forename: Umesh
authors.initials: U
authors.lastname: Kumar
authors.forename: Mika
authors.initials: M
authors.lastname: Sillanpää
mesh_terms: D000327:Adsorption; D000537:Aluminum Oxide / Q000737:chemistry*; D004563:Electrochemistry; D005459:Fluorides / Q000032:analysis / Q000302:isolation & purification*; D015386:Hazardous Substances; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D008956:Models, Chemical; D053758:Nanoparticles; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D013816:Thermodynamics; D014867:Water; D014874:Water Pollutants, Chemical / Q000302:isolation & purification; D018508:Water Purification; D014961:X-Ray Diffraction
chemical_list: D015386:Hazardous Substances; D012996:Solutions; D014874:Water Pollutants, Chemical; D014867:Water; D000537:Aluminum Oxide; D005459:Fluorides