کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1405884 | 1501760 | 2013 | 10 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Physicochemical characterisation of natural K-clinoptilolite and heavy-metal forms from Gördes (Manisa, western Turkey) Physicochemical characterisation of natural K-clinoptilolite and heavy-metal forms from Gördes (Manisa, western Turkey)](/preview/png/1405884.png)
• As termed by us, the "rate of ion selectivity" differs from the "ion selectivity" of an ion-exchanged form.
• Decrease in crystallinity is controlled by replacement of heavy metals in the clinoptilolite structure.
• Peak intensities decrease in relation to increasing normality in the Ag+, Cd2+ and Co3+ forms, except the Cr3+ forms.
• The temperature of adsorbed water loss in heavy-metal forms is consistent, that of water of crystallisation increases.
Physicochemical characterisation of natural K-clinoptilolite and heavy-metal (Ag+, Cd2+, Cr3+ and Co3+) forms was accomplished through ion exchange by batch, X-ray diffractometric (XRD), X-ray fluorescence (XRF), infrared-spectral (FT-IR), differential thermal analysis–thermal gravimetric (DTA–TG) and scanning-electron microscopic (SEM) methods. Increasing the normality in the cases of heavy-metal forms resulted in decrease in crystallinity and increases in unit-cell volume, rate of ion exchange, and percentage of ion selectivity. In this study, the order of ion-selectivity percentages (rather than ion selectivity) of heavy-metal forms was determined to be Ag+ > Cd2+ > Cr3+ > Co3+. This finding is consistent with the results of worldwide research on the order of ion selectivity in modified clinoptilolite.
Journal: Journal of Molecular Structure - Volumes 1054–1055, 24 December 2013, Pages 349–358