Fluoride removal mechanism of bayerite/boehmite nanocomposites: roles of the surface hydroxyl groups and the nitrate anions

J Colloid Interface Sci. 2015 Feb 15:440:60-7. doi: 10.1016/j.jcis.2014.10.069. Epub 2014 Nov 6.

Abstract

Three-dimensional feather like bayerite/boehmite nanocomposites were synthesized by a facile one-pot hydrothermal method. The obtained nanocomposites were characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption-desorption isotherms. The removal properties toward fluoride were investigated, including adsorption kinetics, adsorption isotherm, and influences of pH and coexisting anions. The maximal adsorption capacity was 56.80 mg g(-1) at pH 7.0, which is favorable compared to those reported in the literature using other adsorbents. The coexisting of sulfate and bicarbonate inhibited the fluoride removal especially at high concentrations. Furthermore, the removal mechanism was revealed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The results suggest that both of the surface hydroxyl groups and the nitrate anions were participated in the ion-exchange process.

Keywords: Bayerite/boehmite; Fluoride adsorption; Hydroxyl group; Ion-exchange; Nitrate anions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aluminum Hydroxide / chemistry*
  • Aluminum Oxide / chemistry*
  • Anions
  • Fluorides / isolation & purification*
  • Microscopy, Electron, Scanning
  • Microscopy, Electron, Transmission
  • Nanocomposites*
  • Nitrates / chemistry*
  • Surface Properties*
  • X-Ray Diffraction

Substances

  • Anions
  • Nitrates
  • Aluminum Hydroxide
  • aluminum oxide hydroxide
  • Aluminum Oxide
  • Fluorides