Characterization of Sr²⁺uptake on natural minerals of kaolinite and magnesite using XRPD, SEM/EDS, XPS, and DRIFT

Abstract

Sr2+ / Kaolinite / Magnesite Summary. The sorption behavior of Sr 2+ ions on natural minerals rich in kaolinite and magnesite was studied using SEM/EDS, XPS, XRPD, AAS/AES and DRIFT techniques. Quantitative analysis of the XPS data shows that magnesite is more effective in Sr 2+ uptake than kaolinite. DRIFT spectra and XRPD patterns indicate that the structures of both minerals were not affected upon Sr 2+ sorption. Intercalation of DMSO in kaolinite lamellae aiming at increasing the interlayer space did not significantly enhance the sorption capacity of the clay towards Sr 2+ probably due to the lack of a negative charge on the accessible sites. EDS mapping indicated that while the sorbed Sr is equally distributed on surface of natural kaolinite, it was associated -to a larger extent -with the regions richer in Mg in the case of natural magnesite. Comparing the uptake mechanisms of natural magnesite with that of pure MgCO 3 , it was seen that while natural magnesite sorbed Sr 2+ mainly through an ion exchange type mechanism, the formation of SrCO 3 coprecipitate was detected on the surface of the MgCO 3 at higher loadings.

Characterization and Adsorption Behavior of Strontium from Aqueous Solutions onto Chitosan-Fuller’s Earth Beads

“…The H + ion could be released from the CF bead surface into the solution as a result of ion exchange. Therefore, the Sr 2+ adsorption may involve surface hydroxyls of the CF beads according to the ion-exchange mechanism [30,31]:−2normalS−OH+Sr2+⇔(SO2)Sr+2H+ −normalS−OH+Sr2+⇔−SO−Sr2++H+…”

Selective Separation of Uranium and Thorium Using Mesoporous Modified Nano-Alumina from Abu Rusheid Leach Liquor.

“…Therefore, there are considerable research activities in the study of new sorbents. Recently, a number of innovative adsorption materials have been developed and reported for the removal of uranium, thorium and heavy metal cations in general, from their aqueous solutions [10][11][12][13][14][15][16][17][18]. However, many anion exchange resins have been used to extract uranium and thorium ions from both strong acidic and basic solutions, although the most commonly used adsorbents for the extraction of these radionuclides are cation exchange ones [19,20].…”

Adsorption Kinetics and Equilibria of Strontium onto Kaolinite

“…There are numerous reports regarding the adsorption of strontium on many kinds of clay minerals present in and around disposal sites such as montmorillonite (2-6, 10, 11, 14, 16, 19-21, 23, 25), illite (2,3,5,9,13,20,21,24), kaolinite (2-5, 7-9, 15-20, 24), attapulgite (3), calcite (7), magnezite (17), zeolites (18,25), and silica colloids (8,11,22).…”