Co-immobilization of cesium and strontium containing waste by metakaolin-based geopolymer: Microstructure, mineralogy and mechanical properties
Source abstract
Abstract
The present study investigated the possibility of co-immobilization of caesium and strontium containing waste by metakaolin-based (MK) geopolymer. 4% of CsNO3 and 4% of Sr(NO3)2 by weight were used as simulants for radioactive Cs and Sr. The effect of Cs and Sr on the geopolymerization kinetics was determined via isothermal calorimetry. Furthermore, the evolution of mechanical properties, microstructure, and mineralogy was analysed. The results showed that Cs exerted no noticeable effect on reaction kinetics while Sr lowered the geo-polymerization degree of MK geopolymer due to part of OH- from the activating solution being consumed by Sr2+, thereby reducing the activating capacity of pore solution. In addition, the pore structure analysis showed that the incorporation of Sr coarsened the microstructure of MK geopolymer while no significant change was observed with Cs. The phase analysis showed that no new phase was formed because of Cs or Sr incorporation. The mechanical properties decreased with Cs and Sr addition and a higher strength loss was observed for Sr-bearing geopolymers than that of Cs-bearing matrices. The strength reduction in Cs-bearing matrices is associ-ated with the accompanying nitrate ions while a more pronounced strength reduction in Sr-bearing specimens is due to the synergistic effect of nitrates and Sr2+ on the geopolymerization. Despite that, the compressive strengths for all tested MK recipes met the minimum Belgian waste form acceptance criteria indicating that MK geopolymer preserved sufficient strength even at high Cs and Sr waste loadings. Thermodynamic modelling based on speciation and saturation index revealed that Cs+ was mainly bound through ion exchange, whereas Sr2+ largely precipitated as SrCO3. More importantly, it was observed that the co-immobilization of Cs and Sr by MK geopolymer is largely influenced by Sr behaviour. Based on the findings, it can be concluded that MK geopolymer is an excellent host material for Cs and Sr-based waste.
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Research context
OpenAlex topics: Nuclear materials and radiation effects · Chemical Synthesis and Characterization · Concrete and Cement Materials Research
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References (59)
Show source-provided references
1. Multilayer shielding design for intermediate radioactive waste storage drums: a comparative study between FLUKA and QAD-CGA10.1155/2019/8186798 ↗
2. A review of the demonstration of innovative solvent extraction processes for the recovery of trivalent minor actinides from PUREX raffinate10.1524/ract.2012.1962 ↗
3. A gamma dose rate estimation model for radioactive waste containers
4. Separations and transmutation criteria to improve utilization of a geologic repository10.13182/NT06-3 ↗
5. Chem Soc Rev Process intensification of element extraction using centrifugal contactors in the nuclear fuel cycle10.1039/D2CS00192F ↗
6. Develoment of cesium and strontium separation and immobilization technologies in support of an advanded nuclear fuel cycle
7. Direct separation of minor actinides from high level liquid waste by Me 2 -CA-BTP/SiO2-P adsorbent10.1038/s41598-017-14758-2 ↗
8. Risk analysis of high level radioactive waste storage tank based on HAZOP10.1016/j.anucene.2018.04.021 ↗
9. The ASOF project – advanced separation for the optimal management of spent fuel
10. Influence of gamma ray irradiation on metakaolin based sodium geopolymer10.1016/j.jnucmat.2013.06.044 ↗
11. The effect of high dose rate gamma irradiation on the curing of CaO-FexOy-SiO2 slag based inorganic polymers: mechanical and microstructural analysis10.1016/j.jnucmat.2020.152237 ↗
12. Geopolymers from fly ash and their gamma irradiation10.1016/j.matlet.2018.05.088 ↗
13. Geopolymerisation kinetics. 3. Effects of Cs and Sr salts10.1016/j.ces.2008.06.008 ↗
14. Formulation of caesium based and caesium containing geopolymers10.1179/174367609X422072 ↗
15. Effect of cement addition, solution resting time and curing characteristics on fly ash based geopolymer concrete performance10.1016/j.conbuildmat.2016.07.043 ↗
16. The effect of various si/al, na/al molar ratios and free water on micromorphology and macro-strength of metakaolin-based geopolymer
17. Early-stage geopolymerization revealed by 27Al and 29Si nuclear magnetic resonance spectroscopy based on vacuum dehydration10.1016/j.conbuildmat.2020.121114 ↗
18. Immobilization of simulated radionuclide 133Cs+ by fly ash-based geopolymer10.1016/j.jhazmat.2013.08.049 ↗
19. Strength and microstructure characteristics of metakaolin-based geopolymer mortars with high water-to-binder ratios10.3390/su14063141 ↗
20. Effects SiO2/Na2O molar ratio on mechanical properties and the microstructure of nano-SiO2 metakaolin-based geopolymers10.1016/j.conbuildmat.2013.12.003 ↗
21. Immobilization of simulated low and intermediate level waste in alkali-activated slag-fly ash-metakaolin hydroceramics10.1016/j.nucengdes.2016.01.011 ↗
22. Effects of microwave energy on fast compressive strength development of coal bottom ash-based geopolymers10.1038/s41598-019-52160-2 ↗
23. Thermal resistance variations of fly ash geopolymers: foaming responses10.1038/srep45355 ↗
24. Ambient temperature drying shrinkage and cracking in metakaolin-based geopolymers10.1111/j.1551-2916.2012.05380.x ↗
25. Alteration in molecular structure of alkali activated slag with various water to binder ratios under accelerated carbonation
26. Treatment technology of hazardous water contaminated with radioisotopes with paper sludge ash-based geopolymer-stabilization of immobilization of strontium and cesium by mixing seawater
27. Overview of nuclear materials and nuclear corrosion science and engineering
28. Incorporating Cs and Sr into blast furnace slag inorganic polymers and their effect on matrix properties10.1016/j.jnucmat.2018.02.023 ↗
29. Effect of limestone fillers on microstructure and permeability due to carbonation of cement pastes under controlled CO2 pressure conditions10.1016/j.conbuildmat.2015.02.093 ↗
30. Profex: a graphical user interface for the Rietveld refinement program BGMN10.1107/S1600576715014685 ↗
31. Diffusive transport of dissolved gases in potential concretes for nuclear waste disposal10.3390/su131810007 ↗
32. D.L. Parkhurst and C.A.J. Appelo, Description of input and examples for PHREEQC Version 3-a computer one-dimensional transport, and inverse program for speciation, batch-reaction, geochemical calculations, in: Model. Tech., U.S. Geological Survey Techniques and Methods, 2013: p. 497. 10.1097/00000446-195210000-00005.10.3133/tm6A43 ↗
33. Cemdata18: a chemical thermodynamic database for hydrated Portland cements and alkali-activated materials10.1016/j.cemconres.2018.04.018 ↗
34. Thermodynamic properties of sodium aluminosilicate hydrate (N-A-S-H)10.1039/D1DT02202D ↗
35. Understanding hydration heat of mortars containing supplementary cementitious materials with potential to immobilize heavy metal containing waste10.1016/j.cemconcomp.2020.103859 ↗
36. Calorimetric study of geopolymer binders based on natural pozzolan10.1007/s10973-016-5850-7 ↗
37. Geopolymerization process of alkali-metakaolinite characterized by isothermal calorimetry10.1016/j.tca.2009.04.002 ↗
38. Physical barrier effect of geopolymeric waste form on diffusivity of cesium and strontium10.1016/j.jhazmat.2016.07.003 ↗
39. The effect of ionic contaminants on the early-age properties of alkali-activated fly ash-based cements10.1016/S0008-8846(01)00724-4 ↗
40. Group 16 (O, S, Se, Te) alkaline earth compounds
41. Nanoparticles of Sr(OH)2: synthesis in homogeneous phase at low temperature and application for cultural heritage artefacts10.1007/s00339-008-4464-8 ↗
42. Precipitation of alkaline-earth metal silicate hydrates from aqueous solution: ionic equilibria, crystalline phases and precipitation mechanisms10.1002/crat.2170210502 ↗
43. The effect of Cs and Sr on the mechanical properties of blast furnace slag inorganic polymer for radioactive waste immobilisation
44. Impact of sulfate and nitrate incorporation on potassium- and sodium-based geopolymers: geopolymerization and materials properties10.1007/s10853-011-5516-6 ↗
45. Alkali activation of fly ash in the presence of sodium nitrate10.1007/s12649-021-01584-x ↗
46. A review of recent developments and advances in eco-friendly geopolymer concrete10.3390/app10217838 ↗
47. Aqueous leachability of metakaolin-based geopolymers with molar ratios of Si/Al = 1.5-410.1016/j.jnucmat.2008.06.015 ↗
48. Effect of sulphate and nitrate anions on heavy metal immobilisation in ferronickel slag geopolymers10.1016/j.clay.2012.09.018 ↗
49. Interplay between storage temperature, medium and leaching kinetics of hazardous wastes in Metakaolin-based geopolymer10.1016/j.jhazmat.2019.121377 ↗
50. Immobilization of cesium in alkaline activated fly ash matrix10.1016/j.jnucmat.2005.06.006 ↗
51. Incorporation of strontium and calcium in geopolymer gels10.1016/j.jhazmat.2019.121015 ↗
52. Impact of alkali cations on properties of metakaolin and metakaolin/slag geopolymers: microstructures in relation to sorption of 134Cs radionuclide10.1016/j.jhazmat.2017.11.049 ↗
53. A multiscale investigation of reaction kinetics, phase formation, and mechanical properties of metakaolin geopolymers10.1016/j.cemconcomp.2016.12.010 ↗
54. The formation of crystalline phases in metakaolin-based geopolymers in the presence of sodium nitrate10.1007/s10853-016-9767-0 ↗
55. Transmission electron microscopy and nuclear magnetic resonance studies of geopolymers for radioactive waste immobilization10.1111/j.1551-2916.2007.01532.x ↗
56. Immobilization of cesium in fly ash-silica fume based geopolymers with different Si/Al molar ratios10.1016/j.scitotenv.2019.06.095 ↗
57. Physisorption of gases, with special reference to the evaluation of surface area and pore size distribution (IUPAC Technical Report)10.1515/pac-2014-1117 ↗
58. Application of multiple techniques to quantify pore structure of degraded cementitious materials
59. Ion exchange in geopolymers