Oxides And Hydrous Oxides Of Multivalent Metals As Inorganic Ion Exchangers

Highly selective materials and effective technologies are needed to meet the increasingly stronger drinking water standards for targeted ionic species. Inorganic ion exchangers based on individual and mixed-metal hydrous oxides (or mixed adsorbents that contain inorganic ion exchangers in their composition) are adsorptive materials that are capable of lowering the concentrations of anionic contaminants, such as H2AsO4−, H3AsO3, F−, Br−, BrO3−, HSeO4−, HSeO3− and H3BO3, to 10 μg/L or less. To achieve a higher selectivity towards arsenate, a new ion exchanger based on Mg–Al hydrous oxides was developed by a novel, cost-effective and environmentally friendly synthesis method via a non-traditional (alkoxide-free) sol-gel approach. The exceptional adsorptive capacity of the Mg–Al hydrous oxides towards H2AsO4− (up to 200 mg[As]/gdw) is due to the high affinity of this sorbent towards arsenate (steep equilibrium isotherms) and its fast adsorption kinetics. Because of the mesoporous (as determined by N2 adsorption and SEM) and layered (as determined by XRD and FTIR) structure of the ion-exchange material as well as the abundance of anion exchange sites (as determined by XPS and potentiometric titration) on its surface the material demonstrated very competitive (or very high) removal capacity towards other targeted anions, including fluoride, bromide, bromate, selenate, selenite, and borate.

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Group IV Hydrous Oxides — Synthetic Inorganic Ion Exchangers

Inorganic Ion Exchange Materials ◽

10.1201/9781351073561-5 ◽

2018 ◽

pp. 141-160

Author(s):

A. Ruvarac

Keyword(s):

Group Iv ◽

Ion Exchangers ◽

Inorganic Ion Exchangers ◽

Inorganic Ion ◽

Hydrous Oxides

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Synthetic inorganic ion-exchangers—I Hydrous oxides and acidic salts of multivalent metals

Talanta ◽

10.1016/0039-9140(72)80075-4 ◽

1972 ◽

Vol 19 (3) ◽

pp. 219-262 ◽

Cited By ~ 293

Author(s):

V Veselý

Keyword(s):

Ion Exchangers ◽

Inorganic Ion Exchangers ◽

Inorganic Ion ◽

Hydrous Oxides

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Instrumental neutron activation analysis of lanthanides and coexisting elements in monazite samples and group separation using synthesized inorganic ion exchangers

Radiochimica Acta ◽

10.1515/ract-2019-3192 ◽

2020 ◽

Vol 108 (11) ◽

pp. 901-912

Author(s):

Mohamed A. Ghamry ◽

Fatma H. El-Sweify ◽

Alaa El-Din A. Abdel-Fattah ◽

Shorouk M. Aly ◽

Mohamed F. El-Shahat

Keyword(s):

Neutron Activation Analysis ◽

Instrumental Neutron Activation Analysis ◽

Activation Analysis ◽

Neutron Activation ◽

Group Separation ◽

Ion Exchangers ◽

Inorganic Ion Exchangers ◽

Inorganic Ion ◽

Lanthanide Elements ◽

Instrumental Neutron Activation

AbstractSamples of Egyptian monazite ore obtained from black sand of Abu-Khashaba, Rashied (Rosetta) area on the Mediterranean Sea coast were analyzed for some lanthanides and coexisting elements using instrumental neutron activation analysis (INAA). The analyses were carried out qualitatively and quantitatively for the elements Ce, Nd, Eu, Gd, Tb, Yb and Sc, La as well as the accompanying elements Co, Cr, Fe, Hf, Nb, Zn, Zr in addition to the actinides Th and U; whereas after relatively longer decay time the following lanthanide elements were analyzed: Ce, Nd, Eu, Gd, Tb, Yb and Sc, beside the accompanying elements Co, Cr, Fe, Hf, Nb, Zn, Zr and Th. Two certified reference materials (CRM) were used in this study. For sorption studies, radioactive isotopes 141Ce, 160Tb, 169Yb, 95Zr, 181Hf, and 95Nb were prepared by neutron irradiation to trace the adsorption behaviors of their corresponding elements under certain conditions. Furthermore, radiochemical separation of the analyzed elements in the irradiated monazite samples in sulfuric acid solutions was carried out. Ion exchange technique was applied under static and dynamic conditions and the employed inorganic ion exchangers were locally synthesized and characterized using FT-IR and scanning electron microscopy (SEM) tools. Good group separation of the analyzed lanthanide elements from the accompanying elements was achieved.

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