Adsorption of Fluoride from Aqueous Solution Using Low-Cost Bentonite/Chitosan Beads


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.

Share and Cite:

Y. Zhang, D. Wang, B. Liu, X. Gao, W. Xu, P. Liang and Y. Xu, "Adsorption of Fluoride from Aqueous Solution Using Low-Cost Bentonite/Chitosan Beads," American Journal of Analytical Chemistry, Vol. 4 No. 7A, 2013, pp. 48-53. doi: 10.4236/ajac.2013.47A007.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] W. Ma, F.-Q. Ya, M. Han and R. Wang, “Characteristics of Equilibrium, Kinetics Studies for Adsorption of Fluoride on Magnetic-Chitosan Particle,” Journal of Hazardous Materials, Vol. 143, No. 1, 2007, pp. 296-302. doi:10.1016/j.jhazmat.2006.09.032
[2] C. Sairam Sundaram, N. Viswanathan and S. Meenakshi, “Fluoride Sorption by Nano-Hydroxyapatite/Chitin Composite,” Journal of Hazardous Materials, Vol. 172, No. 1, 2009, pp. 147-151. doi:10.1016/j.jhazmat.2009.06.152
[3] D. Thakre, S. Jagtap, N. Sakhare, N. Labhsetwar, S. Meshram and S. Rayalu, “Chitosan Based Mesoporous Ti-Al Binary Metal Oxide Supported Beads for Defluoridation of Water,” Chemical Engineering Journal, Vol. 158, No. 2, 2010, pp. 315-324. doi:10.1016/j.cej.2010.01.008
[4] A. Yehia and K. Ezzat, “Fluoride Ion Uptake by Synthetic Apatites,” Adsorption Science & Technology, Vol. 27, No. 3, 2009, pp. 337-347. doi:10.1260/026361709789868910
[5] S. P. Kamble, P. Dixit, S. S. Rayalu and N. K. Labhsetwar, “Defluoridation of Drinking Water Using Chemically Modified Bentonite Clay,” Desalination, Vol. 249, No. 2, 2009, pp. 687-693. doi:10.1016/j.desal.2009.01.031
[6] P. Miretzky and A. F. Cirelli, “Fluoride Removal from Water by Chitosan Derivatives and Composites: A Review,” Journal of Fluorine Chemistry, Vol. 132, No. 4, 2011, pp. 231-240. doi:10.1016/j.jfluchem.2011.02.001
[7] X. Y. Wang, D. F. Wang, P. Liang and X. G. Liang, “Synthesis and Properties of an Insoluble Chitosan Resin Modified by Azamacrocycle Copper(II) Complex for Protein Hydrolysis,” Journal of Applied Polymer Science, Vol. 128, No. 5, 2013, pp. 3080-3288. doi:10.1002/app.38461
[8] B. Liu, D. Wang, X. Gao, L. Zhang, Y. Xu and Y. Li, “Removal of Arsenic from Laminaria Japonica Aresch Juice Using As (III)-Imprinted Chitosan Resin,” European Food Research and Technology, Vol. 232, No. 5, 2011, pp. 911-917. doi:10.1007/s00217-011-1460-6
[9] N. Viswanathan, C. S. Sundaram and S. Meenakshi, “Removal of Fluoride from Aqueous Solution Using Protonated Chitosan Beads,” Journal of Hazardous Materials, Vol. 161, No. 1, 2009, pp. 423-430. doi:10.1016/j.jhazmat.2008.03.115
[10] B. Liu, D. Wang, Y. Xu and G. Huang, “Adsorption Properties of Cd(II)-Imprinted Chitosan Resin,” Journal of Materials Science, Vol. 46, No. 5, 2011, pp. 1535-1541. doi:10.1007/s10853-010-4958-6
[11] A. S. Özcan and A. Özcan, “Adsorption of Acid Dyes from Aqueous Solutions onto Acid-Activated Bentonite,” Journal of Colloid and Interface Science, Vol. 276, No. 1, 2004, pp. 39-46. doi:10.1016/j.jcis.2004.03.043

Copyright © 2023 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.