In:
Clays and Clay Minerals, Cambridge University Press (CUP), Vol. 67, No. 4 ( 2019-08), p. 291-305
Abstract:
Adsorption of uranyl (UO 2 2+ ) ions to mineral surfaces is a potentially effective method for removing this hazardous metal from water, but other toxic trace metal ions ( X n + : Rb + , Sr 2+ , Cr 3+ , Mn 2+ , Ni 2+ , Zn 2+ , Cd 2+ ) in uraniferous wastewaters compete with UO 2 2+ for adsorption sites and thus may diminish the capacity of adsorbents to sequester UO 2 2+ . A better understanding of competitive adsorption among these metal ions and the development of better adsorbents are, therefore, of critical importance. The purpose of the present study was to synthesize and characterize magnetic adsorbents, consisting of M Fe 2 O 4 ( M = Mn, Fe, Zn, Co, or Ni) nanoparticles synthesized on montmorillonite (Mnt) edge sites, and to investigate their use as adsorbents for UO 2 2+ , including competitive adsorption with trace metal ions. Selective adsorption was studied using Langmuir, Freundlich, and Dubinin-Radushkevich isotherms, and the results showed that X n + ions were adsorbed primarily on M Fe 2 O 4 -montmorillonite surfaces, and the UO 2 2+ ions were adsorbed on the interfaces between montmorillonite edge surfaces and M Fe 2 O 4 nanoparticles. Using the Freundlich model, the interface adsorption capacity of UO 2 2+ reached 25.1 mg·g –1 in mixed solution. Further, the UO 2 2+ and Cr 3+ ions had a redox reaction on the interfaces with synergistic adsorption. Herein, the adsorption capacity of Cr 3+ was 60.2 mg·g –1 using the Freundlich isotherm. The results demonstrated that the M Fe 2 O 4 -montmorillonite with highly selective adsorption of UO 2 2+ ions is applicable to UO 2 2+ treatment in the presence of toxic trace metal ions. Graphical abstract
Type of Medium:
Online Resource
ISSN:
0009-8604
,
1552-8367
DOI:
10.1007/s42860-019-00028-x
Language:
English
Publisher:
Cambridge University Press (CUP)
Publication Date:
2019
detail.hit.zdb_id:
2045991-9
detail.hit.zdb_id:
221428-3
SSG:
13
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