University of Tasmania
Browse

File(s) under permanent embargo

Size-dependent defluoridation properties of synthetic hydroxyapatite

journal contribution
posted on 2023-05-18, 00:26 authored by Gao, S, Sun, R, Wei, Z, Zhao, H, Li, H, Hu, F
Batch adsorption experiments were conducted to investigate the removal of fluoride from aqueous solution by the addition of synthetic hydroxyapatites (HAps) with different particle sizes. Results showed that size-dependent defluoridation properties of HAps. Better performances were obtained with smaller particle sized HAps, which presented higher adsorption efficiency. Bulk HAp, the HAp sample with the largest particle size, presented the lowest percentage of fluoride removal. The isotherm studies showed that the Freundlich model was the best choice to describe the adsorption behaviors of nanosized HAps. However, the adsorption pattern of the bulk sample followed both Langmuir and Freundlich isotherms. All parameters that might influence the defluoridation process were assessed, which included the effect of adsorbent dose, initial fluoride concentration, contact time and the effect of temperature. The removal efficiency of fluoride increased with increasing adsorbent dose. Decrease of the initial fluoride concentration resulted in the increase of fluoride removal efficiency. The percentage of fluoride removal increased as the ambient pH decreased. Thermodynamic parameters suggested that the adsorption of fluoride onto HAp samples was physisorption and endothermic in nature. Moreover, adsorption kinetic study revealed that the adsorption process followed pseudo-second-order kinetics. This work indicated that synthetic hydroxyapatites, especially the smaller particle sized HAps, were efficient defluoridation materials.

History

Publication title

Journal of Fluorine Chemistry

Volume

130

Issue

6

Pagination

550-556

ISSN

0022-1139

Department/School

School of Natural Sciences

Publisher

Elsevier Science Sa

Place of publication

Po Box 564, Lausanne, Switzerland, 1001

Rights statement

Copyright 2009 Elsevier B.V.

Repository Status

  • Restricted

Socio-economic Objectives

Expanding knowledge in the chemical sciences

Usage metrics

    University Of Tasmania

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC