Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Leaching Characteristics of Cs from the Decomposed Cu Ferrocyanide Adsorbent Solidified by Portland Cement and Geopolymer
https://orcid.org/http://orcid.org/0000-0001-5835-8636
The use of cement technology is under investigation for the disposal of 137Cs, which is a type of radioactive waste and which was dispersed as a result of the accident. Here, we present the results of a study on the leaching characteristics of Cs from solidified bodies. Combustible materials contaminated with radioactive Cs released by the accident at the TEPCO's Fukushima Daiichi NPS are incinerated to reduce their volume, and the incineration residue is further reduced by melting treatment. Cs exists as water-soluble salts in the molten fly ash. The Cs can be transferred to the liquid phase by washing, and the Cs can be further concentrated by ion-exchange chromatography using Cs adsorbents such as ferrocyanide transition metal salts. The adsorbent used must be stabilized for final disposal. We present an example of using copper ferrocyanide as an adsorbent in this process. Copper ferrocyanide was calcined and decomposed, then solidified with Portland cement or metakaolin geopolymer. Since cement hydrate has no cation exchange property, all Cs leached into pure water, but copper ferrocyanide, after pyrolysis, became cation exchangeable in the alkaline environment of Portland cement, resulting in a Cs leaching rate of only 20%. The Cs leaching rate from the geopolymer solidified body was 2% because the geopolymer is an ion exchanger and has a large Cs ion selectivity for Na ions. However, from the viewpoint of workability during mixing, there was an upper limit to the amount of material to be treated, and cement solidification was superior in terms of volume reduction.
Leaching Characteristics of Cs from the Decomposed Cu Ferrocyanide Adsorbent Solidified by Portland Cement and Geopolymer
https://orcid.org/http://orcid.org/0000-0001-5835-8636
The use of cement technology is under investigation for the disposal of 137Cs, which is a type of radioactive waste and which was dispersed as a result of the accident. Here, we present the results of a study on the leaching characteristics of Cs from solidified bodies. Combustible materials contaminated with radioactive Cs released by the accident at the TEPCO's Fukushima Daiichi NPS are incinerated to reduce their volume, and the incineration residue is further reduced by melting treatment. Cs exists as water-soluble salts in the molten fly ash. The Cs can be transferred to the liquid phase by washing, and the Cs can be further concentrated by ion-exchange chromatography using Cs adsorbents such as ferrocyanide transition metal salts. The adsorbent used must be stabilized for final disposal. We present an example of using copper ferrocyanide as an adsorbent in this process. Copper ferrocyanide was calcined and decomposed, then solidified with Portland cement or metakaolin geopolymer. Since cement hydrate has no cation exchange property, all Cs leached into pure water, but copper ferrocyanide, after pyrolysis, became cation exchangeable in the alkaline environment of Portland cement, resulting in a Cs leaching rate of only 20%. The Cs leaching rate from the geopolymer solidified body was 2% because the geopolymer is an ion exchanger and has a large Cs ion selectivity for Na ions. However, from the viewpoint of workability during mixing, there was an upper limit to the amount of material to be treated, and cement solidification was superior in terms of volume reduction.
Leaching Characteristics of Cs from the Decomposed Cu Ferrocyanide Adsorbent Solidified by Portland Cement and Geopolymer
https://orcid.org/http://orcid.org/0000-0001-5835-8636
The use of cement technology is under investigation for the disposal of 137Cs, which is a type of radioactive waste and which was dispersed as a result of the accident. Here, we present the results of a study on the leaching characteristics of Cs from solidified bodies. Combustible materials contaminated with radioactive Cs released by the accident at the TEPCO's Fukushima Daiichi NPS are incinerated to reduce their volume, and the incineration residue is further reduced by melting treatment. Cs exists as water-soluble salts in the molten fly ash. The Cs can be transferred to the liquid phase by washing, and the Cs can be further concentrated by ion-exchange chromatography using Cs adsorbents such as ferrocyanide transition metal salts. The adsorbent used must be stabilized for final disposal. We present an example of using copper ferrocyanide as an adsorbent in this process. Copper ferrocyanide was calcined and decomposed, then solidified with Portland cement or metakaolin geopolymer. Since cement hydrate has no cation exchange property, all Cs leached into pure water, but copper ferrocyanide, after pyrolysis, became cation exchangeable in the alkaline environment of Portland cement, resulting in a Cs leaching rate of only 20%. The Cs leaching rate from the geopolymer solidified body was 2% because the geopolymer is an ion exchanger and has a large Cs ion selectivity for Na ions. However, from the viewpoint of workability during mixing, there was an upper limit to the amount of material to be treated, and cement solidification was superior in terms of volume reduction.
Leaching Characteristics of Cs from the Decomposed Cu Ferrocyanide Adsorbent Solidified by Portland Cement and Geopolymer
RILEM Bookseries
Jędrzejewska, Agnieszka (Herausgeber:in) / Kanavaris, Fragkoulis (Herausgeber:in) / Azenha, Miguel (Herausgeber:in) / Benboudjema, Farid (Herausgeber:in) / Schlicke, Dirk (Herausgeber:in) / Yamada, Kazuo (Autor:in) / Ichikawa, Tsuneki (Autor:in) / Tojo, Yasumasa (Autor:in) / Endo, Kazuto (Autor:in)
International RILEM Conference on Synergising expertise towards sustainability and robustness of CBMs and concrete structures ; 2023 ; Milos Island, Greece
09.06.2023
10 pages
Aufsatz/Kapitel (Buch)
Elektronische Ressource
Englisch
| DOAJ | 2019
Comparison of the Thermal Characteristics of Portland Cement and Geopolymer Cement Concrete Mixes
| Online Contents | 2017
Comparison of the Thermal Characteristics of Portland Cement and Geopolymer Cement Concrete Mixes
| Online Contents | 2017