Development of multifunctional chitosan beads for fluoride removal

J Hazard Mater. 2009 Aug 15;167(1-3):325-31. doi: 10.1016/j.jhazmat.2008.12.123. Epub 2009 Jan 10.

Abstract

Chitosan beads (CB) which have negligible defluoridation capacity (DC) have been chemically modified by introducing multifunctional groups, viz., NH(3)(+) and COOH groups by means of protonation and carboxylation in order to utilize both amine and hydroxyl groups for fluoride removal. The protonated cum carboxylated chitosan beads (PCCB) showed a maximum DC of 1800 mg F(-)/kg whereas raw chitosan beads displayed only 52 mg F(-)/kg. Sorption process was found to be independent of pH and slightly influenced in the presence of other common anions. The fluoride sorption on modified forms was reasonably explained by Freundlich and Langmuir isotherms. The sorbents were characterised by FTIR and SEM with EDAX analysis. The sorption process follows pseudo-second-order and intraparticle diffusion kinetic models. The suitability of PCCB has been tested with field sample collected from a nearby fluoride endemic area.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adsorption
  • Ammonia
  • Anions
  • Carboxylic Acids
  • Chitosan / chemistry*
  • Environmental Pollutants / isolation & purification*
  • Fluorides / isolation & purification*
  • Kinetics
  • Microspheres
  • Spectrum Analysis

Substances

  • Anions
  • Carboxylic Acids
  • Environmental Pollutants
  • Ammonia
  • Chitosan
  • Fluorides