Investigation of chabazitic materials as Cs-137 sorbents from cementitious aqueous solutions
| Autor: | Nikolaos Kantiranis, Eric Breynaert, Panagiotis Misaelides, Anestis Filippidis, S. Sarri, B. de Blochouse, André Maes, Fotini Noli |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Cement
Chabazite Aqueous solution Chemistry Sorption General Chemistry 010501 environmental sciences 010403 inorganic & nuclear chemistry Condensed Matter Physics 01 natural sciences 0104 chemical sciences chemistry.chemical_compound Mechanics of Materials concrete General Materials Science Leaching (metallurgy) zeolite Saturation (chemistry) Zeolite Ammonium acetate 0105 earth and related environmental sciences Nuclear chemistry |
| Zdroj: | Microporous and Mesoporous Materials. 266:183-188 |
| ISSN: | 1387-1811 |
| Popis: | The ability of a chabazite-bearing tuff (AT), a synthetic chabazite (SYN) and pure natural chabazite crystals (CHA) to sorb cesium (CCs: 10−9 - 10−2 M) from young concrete pore water (YCW), an aqueous medium that can potentially leach from cement-based barriers of radioactive waste disposal facilities, was investigated using a batch technique and 137CsCl-spiked solutions. The sorbents were mineralogically characterized prior and after the sorption tests, whereas their uptake ability was determined by the ammonium acetate saturation (AMAS) method. Two series of experiments were performed using sorbate solutions in pH∼13 and pH∼7 YCW (contact time: 14 days and 100 days). The Cs-uptake by the zeolites was determined by counting the 661.6 keV 137Cs γ-rays in the liquid phase. SYN presented the highest Cs-uptake ability followed by CHA and AT. The Cs-uptake, which remained constant between 14 and 100 days, depended on the zeolite content of the sorbents and the Cs-concentration of the solutions. The zeolites remained stable in the YCW environment for the total duration of the experiment. Kinetic experiments, performed for AT at 23, 35 and 50 °C using a 10−3 M Cs-solution in pH∼13 YCW spiked with 137Cs, showed that the equilibrium was established, for all temperatures, in less than 30 min. Cs-leaching tests (duration: 14 days and 100 days) performed using pH ∼13 YCW as eluent, indicated that AT was the most sensitive to leaching losing ca. 60% of the sorbed Cs in less than 10 min, whereas SYN and CHA ca. 30%. No further leaching was observed at prolonged contact of the Cs-loaded zeolites with YCW. ispartof: Microporous and Mesoporous Materials vol:266 pages:183-188 status: published |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect