Application of Modified Bentonites for Arsenite (III) Removal from Drinking Water

  • Dóra Buzetzky Lajos Imre Isotope Laboratory, Department of Physical Chemistry, Institute of Chemistry, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Egyetem tér 1, Hungary
  • Noémi Csilla Tóth Agilent Atomic Spectroscopy Partner Laboratory, Department of Inorganic and Analytical Chemistry, Institute of Chemistry, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Egyetem tér 1, Hungary
  • Noémi M. Nagy Lajos Imre Isotope Laboratory, Department of Physical Chemistry, Institute of Chemistry, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Egyetem tér 1, Hungary
  • József Kónya Lajos Imre Isotope Laboratory, Department of Physical Chemistry, Institute of Chemistry, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Egyetem tér 1, Hungary

Abstract

Four modified bentonites (La(III), Ce(III), Y(III), Fe(III)) were prepared by ion exchange process to remove arsenite (III) ions from water. The modified bentonites were examined with X-ray fluorescence spectroscopy (XRF) and X-ray diffraction (XRD). The rare earth (REE) and Fe(III) ion content in bentonite was higher than the CEC values obtained by ammonium acetate method related to trivalent ions (2.7 x 10-4 mol g-1). The kinetics, equilibrium time, sorption isotherms and desorption experiments were examined. Lanthanum, yttrium and cerium bentonite can bind similar amount of arsenite(III) ions. Iron-bentonite cannot bind significant amounts of arsenite ions. The active sites and the solubilities of the sorption complex were determined. Arsenite (III) ions sorb in the interlayer space as REEAsO3. The solubility of the arsenite complex was two orders of magnitude smaller than that of the phosphate complex. After desorption the eluted amount of arsenite (III) was 55 % related to the sorbed amount of arsenite. The d(001) basal spacing of modified bentonites and that of after sorption and desorption was measured. After the sorption of arsenite ion on lanthanum bentonite, the d(001) basal spacing of montmorillonite was decreased and after desorption an increase in d(001) basal spacing was observed again. Modified bentonites can be used for removing arsenic ions from water.

Keywords: modified bentonite, arsenite (III), rare earth, groundwater, sorption experiments
Published online
2018-08-07
How to Cite
Buzetzky, D., Tóth, N., Nagy, N. and Kónya, J. (2019) “Application of Modified Bentonites for Arsenite (III) Removal from Drinking Water”, Periodica Polytechnica Chemical Engineering, 63(1), pp. 113-121. doi: https://doi.org/10.3311/PPch.12197.
Section
Articles