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Verlagsausgabe
DOI: 10.5445/IR/1000088921
Veröffentlicht am 21.12.2018

Calcium Uptake on Kaolinite and Gibbsite: Effects of Sulfate, pH, and Salt Concentration with Additional Insight from Second Harmonic Generation on Temperature Dependencies with Sapphire-Basal Planes and the Potential Relevance to Ice Nucleation

Abdelmonem, Ahmed; Wang, Yujun; Lützenkirchen, Johannes; Alves, Marcelo Eduardo

Abstract:
Although previous studies have shown that sulfate can either increase cation leaching or enhance cation adsorption in soil, little is known about the factors behind these phenomena. To learn more about them, calcium adsorption experiments were carried out with kaolinite and gibbsite at initial pH values 4 and 6 and in the presence of 1 or 20 mmolc L−1 of either nitrate or sulfate. The results indicated that limited sulfate-calcium coadsorption occurred on gibbsite when it was in contact with the dilute solution of CaSO4.2H2O at pH ~ 7. Regarding mineral and pH values, calcium adsorption from the concentrated solutions decreased with sulfate possibly because of the presence of ~31% of the CaSO40 ion pair in the concentrated CaSO4.2H2O solutions and the low free calcium activity therein. Calcium adsorption on kaolinite and gibbsite from all concentrated solutions was reduced when the initial pH changed from 4 to 6 suggesting a negative salt effect on that process. In addition to indicating negligible participation of gibbsite in calcium adsorption, our findings also suggest that higher amounts of gypsum applied to lime-amended oxisols ... mehr


Zugehörige Institution(en) am KIT Institut für Nukleare Entsorgung (INE)
Institut für Meteorologie und Klimaforschung - Atmosphärische Aerosolforschung (IMK-AAF)
Publikationstyp Buchaufsatz
Jahr 2018
Sprache Englisch
Identifikator URN: urn:nbn:de:swb:90-889218
KITopen-ID: 1000088921
HGF-Programm 12.01.01 (POF III, LK 01)
Erschienen in Advanced Sorption Process Applications [Working Title]
Verlag IntechOpen Limited, London
Vorab online veröffentlicht am 05.11.2018
Schlagworte acidic soils, double-layer screening, gypsum, leaching, oxisols, ice nucleation
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