TITLE:
Adsorption of Fluoride from Aqueous Solution Using Low-Cost Bentonite/Chitosan Beads
AUTHORS:
Yi Zhang, Dongfeng Wang, Bingjie Liu, Xiang Gao, Wei Xu, Peng Liang, Ying Xu
KEYWORDS:
Bentonite; Chitosan; Fluoride; Adsorption; Beads
JOURNAL NAME:
American Journal of Analytical Chemistry,
Vol.4 No.7A,
July
5,
2013
ABSTRACT: A new adsorbent namely bentonite/chitosan beads has been synthesized and
studied for its defluoridation efficiency. Bentonite was activated and the
beads were prepared using the inverse
suspension polymerization method. The bentonite/chitosan beads (bentonite dosage of 3.0 g) showed an adsorption capacity of 0.895 mg/g
whereas chitosan beads had only 0.359 mg/g. The optimal pH value was observed
at pH 5 where the adsorbent reached the maximum defluoridation capacity of
1.164 mg/g. The effect of temperature, contact time and initial fluoride
concentration on the adsorption capacity
of the adsorbent has also been investigated. Scanning electron microscopy
(SEM), energy dispersive X-ray analysis (EDAX) and Fourier-transform infrared
spectrometry (FTIR) were used to characterize the adsorbent. The adsorption of fluoride onto the
adsorbent followed Freundlich isotherm model and pseudo-second order kinetic
model. The fluoride loaded adsorbent could be regenerated using sodium
hydroxide.