Cation immobilization in pyrolyzed simulated spent ion exchange resins

Autores
Luca, Vittorio; Bianchi, Hugo Luis; Manzini, Alberto C.
Año de publicación
2012
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Significant quantities of spent ion exchange resins that are contaminated by an assortment of radioactive elements are produced by the nuclear industry each year. The baseline technology for the conditioning of these spent resins is encapsulation in ordinary Portland cement which has various shortcomings none the least of which is the relatively low loading of resin in the cement and the poor immobilization of highly mobile elements such as cesium. The present study was conducted with cationic resin samples (Lewatit S100) loaded with Cs +, Sr 2+, Co 2+, Ni 2+ in roughly equimolar proportions at levels at or below 30% of the total cation exchange capacity. Low temperature thermal treatment of the resins was conducted in inert (Ar), or reducing (CH 4) gas atmospheres, or supercritical ethanol to convert the hydrated polymeric resin beads into carbonaceous materials that contained no water. This pyrolytic treatment resulted in at least a 50% volume reduction to give mechanically robust spherical materials. Scanning electron microscope investigations of cross-sections of the beads combined with energy dispersive analysis showed that initially all elements were uniformly distributed through the resin matrix but that at higher temperatures the distribution of Cs became inhomogeneous. Although Cs was found in the entire cross-section, a significant proportion of the Cs occurred within internal rings while a proportion migrated toward the outer surfaces to form a crustal deposit. Leaching experiments conducted in water at 25°C showed that the divalent contaminant elements were very difficult to leach from the beads heated in inert atmospheres in the range 200-600°C. Cumulative fractional loses of the order of 0.001 were observed for these divalent elements for temperatures below 500°C. Regardless of the processing temperature, the cumulative fractional loss of Cs in water at 25°C reached a plateau or steady-state within the first 24 h increasing only marginally up 120 h. For unheated beads, a steady-state was reached at a cumulative fractional Cs loss of about 0.0045 while for beads heated to 400°C the steady-state was reached at a value of 0.1. Under comparable conditions leaching of Sr, Co and Ni were close to the detection limits. It is concluded that the fraction of the Cs inventory that was more readily leached derived mainly from Cs phases in the crustal deposit.
Fil: Luca, Vittorio. Comisión Nacional de Energía Atómica; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; Argentina
Fil: Bianchi, Hugo Luis. Comisión Nacional de Energía Atómica. Gerencia del Área de Seguridad Nuclear y Ambiente. Gerencia de Química (CAC); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín; Argentina
Fil: Manzini, Alberto C.. Comisión Nacional de Energía Atómica; Argentina
Materia
pirolisis
resinas de intercambio ionico
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/196324

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spelling Cation immobilization in pyrolyzed simulated spent ion exchange resinsLuca, VittorioBianchi, Hugo LuisManzini, Alberto C.pirolisisresinas de intercambio ionicohttps://purl.org/becyt/ford/1.4https://purl.org/becyt/ford/1Significant quantities of spent ion exchange resins that are contaminated by an assortment of radioactive elements are produced by the nuclear industry each year. The baseline technology for the conditioning of these spent resins is encapsulation in ordinary Portland cement which has various shortcomings none the least of which is the relatively low loading of resin in the cement and the poor immobilization of highly mobile elements such as cesium. The present study was conducted with cationic resin samples (Lewatit S100) loaded with Cs +, Sr 2+, Co 2+, Ni 2+ in roughly equimolar proportions at levels at or below 30% of the total cation exchange capacity. Low temperature thermal treatment of the resins was conducted in inert (Ar), or reducing (CH 4) gas atmospheres, or supercritical ethanol to convert the hydrated polymeric resin beads into carbonaceous materials that contained no water. This pyrolytic treatment resulted in at least a 50% volume reduction to give mechanically robust spherical materials. Scanning electron microscope investigations of cross-sections of the beads combined with energy dispersive analysis showed that initially all elements were uniformly distributed through the resin matrix but that at higher temperatures the distribution of Cs became inhomogeneous. Although Cs was found in the entire cross-section, a significant proportion of the Cs occurred within internal rings while a proportion migrated toward the outer surfaces to form a crustal deposit. Leaching experiments conducted in water at 25°C showed that the divalent contaminant elements were very difficult to leach from the beads heated in inert atmospheres in the range 200-600°C. Cumulative fractional loses of the order of 0.001 were observed for these divalent elements for temperatures below 500°C. Regardless of the processing temperature, the cumulative fractional loss of Cs in water at 25°C reached a plateau or steady-state within the first 24 h increasing only marginally up 120 h. For unheated beads, a steady-state was reached at a cumulative fractional Cs loss of about 0.0045 while for beads heated to 400°C the steady-state was reached at a value of 0.1. Under comparable conditions leaching of Sr, Co and Ni were close to the detection limits. It is concluded that the fraction of the Cs inventory that was more readily leached derived mainly from Cs phases in the crustal deposit.Fil: Luca, Vittorio. Comisión Nacional de Energía Atómica; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; ArgentinaFil: Bianchi, Hugo Luis. Comisión Nacional de Energía Atómica. Gerencia del Área de Seguridad Nuclear y Ambiente. Gerencia de Química (CAC); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín; ArgentinaFil: Manzini, Alberto C.. Comisión Nacional de Energía Atómica; ArgentinaElsevier Science2012-05info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/196324Luca, Vittorio; Bianchi, Hugo Luis; Manzini, Alberto C.; Cation immobilization in pyrolyzed simulated spent ion exchange resins; Elsevier Science; Journal of Nuclear Materials; 424; 1-3; 5-2012; 1-110022-3115CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/doi/10.1016/j.jnucmat.2012.01.004info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-03T10:04:18Zoai:ri.conicet.gov.ar:11336/196324instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-09-03 10:04:18.633CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Cation immobilization in pyrolyzed simulated spent ion exchange resins
title Cation immobilization in pyrolyzed simulated spent ion exchange resins
spellingShingle Cation immobilization in pyrolyzed simulated spent ion exchange resins
Luca, Vittorio
pirolisis
resinas de intercambio ionico
title_short Cation immobilization in pyrolyzed simulated spent ion exchange resins
title_full Cation immobilization in pyrolyzed simulated spent ion exchange resins
title_fullStr Cation immobilization in pyrolyzed simulated spent ion exchange resins
title_full_unstemmed Cation immobilization in pyrolyzed simulated spent ion exchange resins
title_sort Cation immobilization in pyrolyzed simulated spent ion exchange resins
dc.creator.none.fl_str_mv Luca, Vittorio
Bianchi, Hugo Luis
Manzini, Alberto C.
author Luca, Vittorio
author_facet Luca, Vittorio
Bianchi, Hugo Luis
Manzini, Alberto C.
author_role author
author2 Bianchi, Hugo Luis
Manzini, Alberto C.
author2_role author
author
dc.subject.none.fl_str_mv pirolisis
resinas de intercambio ionico
topic pirolisis
resinas de intercambio ionico
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.4
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv Significant quantities of spent ion exchange resins that are contaminated by an assortment of radioactive elements are produced by the nuclear industry each year. The baseline technology for the conditioning of these spent resins is encapsulation in ordinary Portland cement which has various shortcomings none the least of which is the relatively low loading of resin in the cement and the poor immobilization of highly mobile elements such as cesium. The present study was conducted with cationic resin samples (Lewatit S100) loaded with Cs +, Sr 2+, Co 2+, Ni 2+ in roughly equimolar proportions at levels at or below 30% of the total cation exchange capacity. Low temperature thermal treatment of the resins was conducted in inert (Ar), or reducing (CH 4) gas atmospheres, or supercritical ethanol to convert the hydrated polymeric resin beads into carbonaceous materials that contained no water. This pyrolytic treatment resulted in at least a 50% volume reduction to give mechanically robust spherical materials. Scanning electron microscope investigations of cross-sections of the beads combined with energy dispersive analysis showed that initially all elements were uniformly distributed through the resin matrix but that at higher temperatures the distribution of Cs became inhomogeneous. Although Cs was found in the entire cross-section, a significant proportion of the Cs occurred within internal rings while a proportion migrated toward the outer surfaces to form a crustal deposit. Leaching experiments conducted in water at 25°C showed that the divalent contaminant elements were very difficult to leach from the beads heated in inert atmospheres in the range 200-600°C. Cumulative fractional loses of the order of 0.001 were observed for these divalent elements for temperatures below 500°C. Regardless of the processing temperature, the cumulative fractional loss of Cs in water at 25°C reached a plateau or steady-state within the first 24 h increasing only marginally up 120 h. For unheated beads, a steady-state was reached at a cumulative fractional Cs loss of about 0.0045 while for beads heated to 400°C the steady-state was reached at a value of 0.1. Under comparable conditions leaching of Sr, Co and Ni were close to the detection limits. It is concluded that the fraction of the Cs inventory that was more readily leached derived mainly from Cs phases in the crustal deposit.
Fil: Luca, Vittorio. Comisión Nacional de Energía Atómica; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; Argentina
Fil: Bianchi, Hugo Luis. Comisión Nacional de Energía Atómica. Gerencia del Área de Seguridad Nuclear y Ambiente. Gerencia de Química (CAC); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín; Argentina
Fil: Manzini, Alberto C.. Comisión Nacional de Energía Atómica; Argentina
description Significant quantities of spent ion exchange resins that are contaminated by an assortment of radioactive elements are produced by the nuclear industry each year. The baseline technology for the conditioning of these spent resins is encapsulation in ordinary Portland cement which has various shortcomings none the least of which is the relatively low loading of resin in the cement and the poor immobilization of highly mobile elements such as cesium. The present study was conducted with cationic resin samples (Lewatit S100) loaded with Cs +, Sr 2+, Co 2+, Ni 2+ in roughly equimolar proportions at levels at or below 30% of the total cation exchange capacity. Low temperature thermal treatment of the resins was conducted in inert (Ar), or reducing (CH 4) gas atmospheres, or supercritical ethanol to convert the hydrated polymeric resin beads into carbonaceous materials that contained no water. This pyrolytic treatment resulted in at least a 50% volume reduction to give mechanically robust spherical materials. Scanning electron microscope investigations of cross-sections of the beads combined with energy dispersive analysis showed that initially all elements were uniformly distributed through the resin matrix but that at higher temperatures the distribution of Cs became inhomogeneous. Although Cs was found in the entire cross-section, a significant proportion of the Cs occurred within internal rings while a proportion migrated toward the outer surfaces to form a crustal deposit. Leaching experiments conducted in water at 25°C showed that the divalent contaminant elements were very difficult to leach from the beads heated in inert atmospheres in the range 200-600°C. Cumulative fractional loses of the order of 0.001 were observed for these divalent elements for temperatures below 500°C. Regardless of the processing temperature, the cumulative fractional loss of Cs in water at 25°C reached a plateau or steady-state within the first 24 h increasing only marginally up 120 h. For unheated beads, a steady-state was reached at a cumulative fractional Cs loss of about 0.0045 while for beads heated to 400°C the steady-state was reached at a value of 0.1. Under comparable conditions leaching of Sr, Co and Ni were close to the detection limits. It is concluded that the fraction of the Cs inventory that was more readily leached derived mainly from Cs phases in the crustal deposit.
publishDate 2012
dc.date.none.fl_str_mv 2012-05
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/11336/196324
Luca, Vittorio; Bianchi, Hugo Luis; Manzini, Alberto C.; Cation immobilization in pyrolyzed simulated spent ion exchange resins; Elsevier Science; Journal of Nuclear Materials; 424; 1-3; 5-2012; 1-11
0022-3115
CONICET Digital
CONICET
url http://hdl.handle.net/11336/196324
identifier_str_mv Luca, Vittorio; Bianchi, Hugo Luis; Manzini, Alberto C.; Cation immobilization in pyrolyzed simulated spent ion exchange resins; Elsevier Science; Journal of Nuclear Materials; 424; 1-3; 5-2012; 1-11
0022-3115
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/doi/10.1016/j.jnucmat.2012.01.004
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
dc.publisher.none.fl_str_mv Elsevier Science
publisher.none.fl_str_mv Elsevier Science
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
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