KIT | KIT-Bibliothek | Impressum | Datenschutz

Adsorption of strontium onto synthetic iron(III) oxide up to high ionic strength systems

García, D.; Lützenkirchen, J.; Huguenel, M.; Calmels, L.; Petrov, V.; Finck, N.; Schild, D.

Abstract:
In this work, the adsorption behavior of Sr onto a synthetic iron(III) oxide (hematite with traces of goethite) has been studied. This solid, which might be considered a representative of Fe$^{3+}$ solid phases (iron corrosion products), was characterized by X-Ray Diffraction (XRD) and X-Ray Photoelectron Spectroscopy (XPS), and its specific surface area was determined. Both XRD and XPS data are consistent with a mixed solid containing more than 90% hematite and 10% goethite. The solid was further characterized by fast acid-base titrations at different NaCl concentrations (from 0.1 to 5 M). Subsequently, for each background NaCl concentration used for the acid-base titrations, Sr-uptake experiments were carried out involving two different levels of Sr concentration (1 × 10$^{-5}$ and 5 × 10$^{-5}$ M, respectively) at constant solid concentration (7.3 g/L) as a function of −log([H$^{+}$]/M). A Surface Complexation Model (SCM) was fitted to the experimental data, following a coupled Pitzer/surface complexation approach. The Pitzer model was applied to aqueous species. A Basic Stern Model was used for interfacial electrostatics of the system, which includes ion-specific effects via ion-specific pair-formation constants, whereas the Pitzer-approach involves ion-interaction parameters that enter the model through activity coefficients for aqueous species. ... mehr


Verlagsausgabe §
DOI: 10.5445/IR/1000139173
Veröffentlicht am 19.10.2021
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Nukleare Entsorgung (INE)
Publikationstyp Zeitschriftenaufsatz
Publikationsjahr 2021
Sprache Englisch
Identifikator ISSN: 2075-163X
KITopen-ID: 1000139173
HGF-Programm 32.11.01 (POF IV, LK 01) Nuclear Waste Disposal
Weitere HGF-Programme 32.11.03 (POF IV, LK 01) Fundamental Scientific Aspects
Erschienen in Minerals
Verlag MDPI
Band 11
Heft 10
Seiten Art. Nr.: 1093
Vorab online veröffentlicht am 05.10.2021
Schlagwörter adsorption; radionuclides; strontium; hematite; goethite; ionic strength; surface complexation model; Pitzer model
Nachgewiesen in Scopus
Web of Science
KIT – Die Forschungsuniversität in der Helmholtz-Gemeinschaft
KITopen Landing Page