Uranium-thorium disequilibrium in north-east Atlantic waters

International audience In this paper we report and compare the concentrations of 234 Th and 238 U measured in surface and subsurface waters collected in the course of a sampling campaign in the north east Atlantic in June-July 1998. Dissolved 234 Th concentrations in surface waters ranged from 5 to...

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Published in:Journal of Environmental Radioactivity
Main Authors: Smith, K. J., León Vintró, L., Mitchell, P. I., Bally du Bois, P., Boust, D.
Other Authors: University College Dublin Dublin (UCD), Laboratoire de Radioécologie de Cherbourg-Octeville (LRC), Institut de Radioprotection et de Sûreté Nucléaire (IRSN)
Format: Article in Journal/Newspaper
Language:English
Published: HAL CCSD 2004
Subjects:
Online Access:https://doi.org/10.1016/j.jenvrad.2004.01.006
https://hal-normandie-univ.archives-ouvertes.fr/hal-02433546
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spelling fttriple:oai:gotriple.eu:10670/1.oixxaz 2023-05-15T17:38:19+02:00 Uranium-thorium disequilibrium in north-east Atlantic waters Smith, K. J. León Vintró, L. Mitchell, P. I. Bally du Bois, P. Boust, D. University College Dublin Dublin (UCD) Laboratoire de Radioécologie de Cherbourg-Octeville (LRC) Institut de Radioprotection et de Sûreté Nucléaire (IRSN) 2004-01-01 https://doi.org/10.1016/j.jenvrad.2004.01.006 https://hal-normandie-univ.archives-ouvertes.fr/hal-02433546 en eng HAL CCSD Elsevier hal-02433546 doi:10.1016/j.jenvrad.2004.01.006 10670/1.oixxaz https://hal-normandie-univ.archives-ouvertes.fr/hal-02433546 undefined Hyper Article en Ligne - Sciences de l'Homme et de la Société ISSN: 0265-931X EISSN: 1879-1700 Journal of Environmental Radioactivity Journal of Environmental Radioactivity, Elsevier, 2004, 74 (1-3), pp.199 - 210. ⟨10.1016/j.jenvrad.2004.01.006⟩ Scavenging Disequilibrium Thorium Uranium Residence times Colloids Ultrafiltration envir droit Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2004 fttriple https://doi.org/10.1016/j.jenvrad.2004.01.006 2023-01-22T17:36:13Z International audience In this paper we report and compare the concentrations of 234 Th and 238 U measured in surface and subsurface waters collected in the course of a sampling campaign in the north east Atlantic in June-July 1998. Dissolved 234 Th concentrations in surface waters ranged from 5 to 20 Bq m-3 , showing a large deficiency relative to 238 U concentrations (typically 42 Bq m-3). This disequilibrium is indicative of active 234 Th scavenging from surface waters. Observed 234 Th/ 238 U activity ratios, together with corresponding 234 Th particulate concentrations , were used to calculate mean residence times for 234 Th with respect to scavenging onto particles (s diss) and subsequent removal from surface waters (s part). Residence times in the range 5-30 days were determined for s diss and 4-18 days for s part (n ¼ 14). In addition, ultrafiltration experiments at six stations in the course of the same expedition revealed that in northeast Atlantic surface waters a significant fraction (46 AE 17%; n ¼ 6) of the thorium in the (operationally-defined) dissolved phase (0.45 lm) phase. Thus, the time (s c) for fully dissolved 234 Th to appear in the filter-retained fraction is dependent on the rate of colloidal aggregation. Here, we determined s c values in the range 3-17 days. # Article in Journal/Newspaper North East Atlantic Northeast Atlantic Unknown Journal of Environmental Radioactivity 74 1-3 199 210
institution Open Polar
collection Unknown
op_collection_id fttriple
language English
topic Scavenging
Disequilibrium
Thorium
Uranium
Residence times
Colloids
Ultrafiltration
envir
droit
spellingShingle Scavenging
Disequilibrium
Thorium
Uranium
Residence times
Colloids
Ultrafiltration
envir
droit
Smith, K. J.
León Vintró, L.
Mitchell, P. I.
Bally du Bois, P.
Boust, D.
Uranium-thorium disequilibrium in north-east Atlantic waters
topic_facet Scavenging
Disequilibrium
Thorium
Uranium
Residence times
Colloids
Ultrafiltration
envir
droit
description International audience In this paper we report and compare the concentrations of 234 Th and 238 U measured in surface and subsurface waters collected in the course of a sampling campaign in the north east Atlantic in June-July 1998. Dissolved 234 Th concentrations in surface waters ranged from 5 to 20 Bq m-3 , showing a large deficiency relative to 238 U concentrations (typically 42 Bq m-3). This disequilibrium is indicative of active 234 Th scavenging from surface waters. Observed 234 Th/ 238 U activity ratios, together with corresponding 234 Th particulate concentrations , were used to calculate mean residence times for 234 Th with respect to scavenging onto particles (s diss) and subsequent removal from surface waters (s part). Residence times in the range 5-30 days were determined for s diss and 4-18 days for s part (n ¼ 14). In addition, ultrafiltration experiments at six stations in the course of the same expedition revealed that in northeast Atlantic surface waters a significant fraction (46 AE 17%; n ¼ 6) of the thorium in the (operationally-defined) dissolved phase (0.45 lm) phase. Thus, the time (s c) for fully dissolved 234 Th to appear in the filter-retained fraction is dependent on the rate of colloidal aggregation. Here, we determined s c values in the range 3-17 days. #
author2 University College Dublin Dublin (UCD)
Laboratoire de Radioécologie de Cherbourg-Octeville (LRC)
Institut de Radioprotection et de Sûreté Nucléaire (IRSN)
format Article in Journal/Newspaper
author Smith, K. J.
León Vintró, L.
Mitchell, P. I.
Bally du Bois, P.
Boust, D.
author_facet Smith, K. J.
León Vintró, L.
Mitchell, P. I.
Bally du Bois, P.
Boust, D.
author_sort Smith, K. J.
title Uranium-thorium disequilibrium in north-east Atlantic waters
title_short Uranium-thorium disequilibrium in north-east Atlantic waters
title_full Uranium-thorium disequilibrium in north-east Atlantic waters
title_fullStr Uranium-thorium disequilibrium in north-east Atlantic waters
title_full_unstemmed Uranium-thorium disequilibrium in north-east Atlantic waters
title_sort uranium-thorium disequilibrium in north-east atlantic waters
publisher HAL CCSD
publishDate 2004
url https://doi.org/10.1016/j.jenvrad.2004.01.006
https://hal-normandie-univ.archives-ouvertes.fr/hal-02433546
genre North East Atlantic
Northeast Atlantic
genre_facet North East Atlantic
Northeast Atlantic
op_source Hyper Article en Ligne - Sciences de l'Homme et de la Société
ISSN: 0265-931X
EISSN: 1879-1700
Journal of Environmental Radioactivity
Journal of Environmental Radioactivity, Elsevier, 2004, 74 (1-3), pp.199 - 210. ⟨10.1016/j.jenvrad.2004.01.006⟩
op_relation hal-02433546
doi:10.1016/j.jenvrad.2004.01.006
10670/1.oixxaz
https://hal-normandie-univ.archives-ouvertes.fr/hal-02433546
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op_doi https://doi.org/10.1016/j.jenvrad.2004.01.006
container_title Journal of Environmental Radioactivity
container_volume 74
container_issue 1-3
container_start_page 199
op_container_end_page 210
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