Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 27Citation - Scopus: 29Characterization of Sr2+ Uptake on Natural Minerals of Kaolinite and Magnesite Using Xrpd, Sem/Eds, Xps, and Drift(Walter De Gruyter Gmbh, 2005) Shahwan, Talal; Erten, Hasan N.The sorption behavior of Sr2+ 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 Sr2+ uptake than kaolinite. DRIFT spectra and XRPD patterns indicate that the structures of both minerals were not affected upon Sr2+ sorption. Intercalation of DMSO in kaolinite lamellae aiming at increasing the interlayer space did not significantly enhance the sorption capacity of the clay towards Sr2+ 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 MgCO3, it was seen that while natural magnesite sorbed Sr2+ mainly through an ion exchange type mechanism, the formation of SrCO3 coprecipitate was detected on the surface of the MgCO 3 at higher loadings.Article Citation - WoS: 2Citation - Scopus: 4Tof-Sims Depth Profiling Analysis of the Uptake of Ba2+ and Co2+ Ions by Natural Kaolinite Clay(Elsevier Ltd., 2004) Shahwan, Talal; Erten, Hasan N.; Black, Leon; Allen, Geoffrey CharlesThe sorption behavior of Ba2+ and Co2+ ions on a natural clay sample rich in kaolinite was studied using time-of-flight secondary ion mass spectrometry (ToF-SIMS). Depth profiling at 10-Å steps was performed up to a 70-Å matrix depth of the clay prior to and following sorption. The results showed that Co2+ is sorbed in slightly larger quantities than Ba2+, with significant numbers of ions fixed on the outermost surface of the clay. Depletion of the ions K+, Mg 2+, and Ca2+ from the clay lattice was observed to accompany enrichment with Co2+ and Ba2+ ions. The data obtained using X-ray powder diffraction (XRPD) and scanning electron microscopy (SEM) indicated insignificant structural and morphological changes in the lattice of the clay upon sorption of both Ba2+ and Co2+ ions. Analysis using energy dispersive X-ray spectroscopy (EDS) showed that the average atomic percentage (±S.D.) of Ba and Co on kaolinite surface were 0.49±0.11 and 0.61±0.19, respectively, indicating a limited uptake capacity of natural kaolinite for both ions.
