1
|
Abe M, Seko N, Hoshina H, Wada S, Yamasaki S, Sueki K, Sakaguchi A. Simple and convenient preconcentration procedure for the isotopic analysis of uranium in seawater. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2024; 16:2478-2488. [PMID: 38606568 DOI: 10.1039/d3ay01381b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/13/2024]
Abstract
The demand for monitoring anthropogenic U isotopes, 236U and 233U, in seawater will continue to increase due to radioecological issues and the need for tools for environmental dynamics research. In response to this growing demand, herein, a novel and simple method was developed for the collection of U isotopes in seawater, both in the laboratory and field, using a fabric-like amidoxime adsorbent. The results from the adsorption studies showed that the optimum conditions for processing seawater in a glass beaker were as follows: seawater pH 4, amidoxime adsorbent 0.20 mmol per 500 g seawater and an adsorption time of 9 hours. Alternatively, when using a closed polyethylene container in experiments on-board a ship and using the same ratio of adsorbent to seawater as in the beaker experiment in the laboratory, the optimum conditions were as follows: seawater pH 8 and an adsorption time of 24 hours. Under the above-mentioned conditions, more than 95% of the U underwent adsorption in both the beaker and the polyethylene container experiments. In the case of analyte desorption, more than 80% of U in seawater was recovered using 2-3 mol dm-3 HCl or HNO3 as the eluent. Thus, it was concluded that the amidoxime adsorbent can serve as a simple and effective pre-concentration method for the ultra-trace monitoring of U isotopes in seawater.
Collapse
Affiliation(s)
- Minami Abe
- Institute of Life and Environmental Science, University of Tsukuba, Japan.
| | - Noriaki Seko
- Takasaki Institute for Advanced Quantum Science, National Institutes for Quantum Science and Technology, Japan
| | - Hiroyuki Hoshina
- Takasaki Institute for Advanced Quantum Science, National Institutes for Quantum Science and Technology, Japan
| | - Shigeki Wada
- Institute of Life and Environmental Science, University of Tsukuba, Japan.
- Shimoda Marine Research Center, University of Tsukuba, Japan
| | - Shinya Yamasaki
- Institute of Pure and Applied Sciences, University of Tsukuba, Japan
| | - Keisuke Sueki
- Institute of Life and Environmental Science, University of Tsukuba, Japan.
- Institute of Pure and Applied Sciences, University of Tsukuba, Japan
| | - Aya Sakaguchi
- Institute of Life and Environmental Science, University of Tsukuba, Japan.
- Institute of Pure and Applied Sciences, University of Tsukuba, Japan
| |
Collapse
|
2
|
Qiao J, Cao Y, Varttic VP, Steier P. Stratigraphic records and inventories of anthropogenic 233U and 236U in Baltic Sea sediments. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 901:166402. [PMID: 37598960 DOI: 10.1016/j.scitotenv.2023.166402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 08/16/2023] [Accepted: 08/16/2023] [Indexed: 08/22/2023]
Affiliation(s)
- Jixin Qiao
- Department of Environmental and Resource Engineering, Technical University of Denmark, DTU Risø Campus, DK-4000 Roskilde, Denmark.
| | - Yiyao Cao
- Zhejiang Provincial Center for Disease Control and Prevention, 310051 Hangzhou, China
| | - Vesa-Pekka Varttic
- Measurements and Environmental Monitoring, Radiation and Nuclear Safety Authority, Finland
| | - Peter Steier
- VERA Laboratory, Faculty of Physics - Isotope Research, University of Vienna, Währinger Straße 17, A-1090 Vienna, Austria
| |
Collapse
|
3
|
Takahashi H, Sakaguchi A, Hain K, Wiederin A, Kuwae M, Steier P, Takaku Y, Yamasaki S, Sueki K. Reconstructing the chronology of the natural and anthropogenic uranium isotopic signals in a marin sediment core from beppu bay, Japan. Heliyon 2023; 9:e14153. [PMID: 37025796 PMCID: PMC10070371 DOI: 10.1016/j.heliyon.2023.e14153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 02/20/2023] [Accepted: 02/22/2023] [Indexed: 03/07/2023] Open
Abstract
The long-lived U isotopes, 233U and 236U, have been used increasingly in recent years as marine circulation tracers and for identifying sources of uranium contamination in the environment. The sedimentation histories of these two U isotopes in combination with natural 238U were reconstructed for an anoxic sediment core collected from Beppu Bay, Japan, in the western North Pacific Ocean showing good time resolution (less than 2.6 y/sample). The 233U/236U atom ratio showed a prominent peak of (3.20 ± 0.30) × 10-2 around 1957 which can be attributed to the input from atmospheric nuclear weapons tests including thermonuclear tests conducting in the Equatorial Pacific. The integrated 233U/236U ratio of (1.64 ± 0.08) × 10-2 for the sediment was found to be in relatively good agreement with the representative ratio published for global fallout (∼1.4 × 10-2). A prominent increase in the authigenic ratio of 233U/238Ua,s in the leached fraction (1.39 ± 0.11 × 10-11) and the bulk digestion (1.36 ± 0.10 × 10-11) was also observed around 1957. This reflects the input supply of 233U to the seawater which is known to have a relatively constant 238U content. The authigenic 236U/238Ua,s ratio (0.18 ± 0.02 × 10-9) obtained for 1921 increased from the early 1950's to a maximum of (6.59 ± 0.60) × 10-9 around 1962. The variation in this ratio represents well the introduction history of U into the surface environment without site-specific U contamination and the time profile is also consistent with the 137Cs signature. This work thus provides a benchmark for the long-term use of the isotopic U composition as an input parameter for seawater circulation tracers and as a chronological marker for anoxic sediments and sedimentary rocks. Especially the 233U/236U ratio may serve as a key-marker for the new geological age Anthropocene.
Collapse
|
4
|
Lin G, Qiao J, Steier P, Danielsen M, Guðnason K, Joensen HP, Stedmon CA. Tracing Atlantic water transit time in the subarctic and Arctic Atlantic using 99Tc- 233U- 236U. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 851:158276. [PMID: 36029821 DOI: 10.1016/j.scitotenv.2022.158276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 08/18/2022] [Accepted: 08/21/2022] [Indexed: 06/15/2023]
Abstract
The pathway and transport time of Atlantic water passing northern Europe can be traced via anthropogenic radioisotopes released from reprocessing of spent nuclear fuels at Sellafield (SF) and La Hague (LH). These reprocessing derived radioisotopes, with extremely low natural background, are source specific and unique fingerprints for Atlantic water. This study explores a new approach using 99Tc-233U-236U tracer to estimate the transit time of Atlantic water in the coast of Greenland. We isolate the reprocessing plants (RP) signal of 236U (236URP) by incorporating 233U measurements and combine this with 99Tc which solely originates from RP, to estimate the transit time of Atlantic water circulating from Sellafield to the coast of Greenland-Iceland-Faroe Islands. Both being conservative radioisotopes, the temporal variation of 99Tc/236URP ratio in Atlantic water is only influenced by their historic discharges from RP, thus 99Tc/236URP can potentially be a robust tracer to track the transport of Atlantic water in the North Atlantic-Arctic region. Based on our observation data of 99Tc-233U-236U in seawater and the proposed 99Tc/236URP tracer approach, Atlantic water transit times were estimated to be 16-22, 25 and 25 years in the coast of Greenland, Iceland and Faroe Island, respectively. Our estimates from northeast Greenland coastal waters agree with earlier results (17-22 years). Therefore, this work provides an independent approach to estimate Atlantic water transit time with which to compare estimates from ocean modelling and other radiotracer approaches.
Collapse
Affiliation(s)
- Gang Lin
- Department of Environmental and Resource Engineering, Technical University of Denmark, DK-4000 Roskilde, Denmark
| | - Jixin Qiao
- Department of Environmental and Resource Engineering, Technical University of Denmark, DK-4000 Roskilde, Denmark.
| | - Peter Steier
- VERA Laboratory, Faculty of Physics, Isotope Physics, University of Vienna, Währinger Straße 17, A-1090 Vienna, Austria
| | | | | | | | - Colin A Stedmon
- National Institute of Aquatic Resources, Technical University of Denmark, Kemitorvet, 2800 Kgs. Lyngby, Denmark
| |
Collapse
|
5
|
Qiao J, Heldal HE, Steier P. Understanding source terms of anthropogenic uranium in the Arctic Ocean - First 236U and 233U dataset in Barents Sea sediments. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 847:157503. [PMID: 35872206 DOI: 10.1016/j.scitotenv.2022.157503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 07/15/2022] [Accepted: 07/15/2022] [Indexed: 06/15/2023]
Abstract
This work reports the first dataset of 236U and 233U in sediment cores taken from the Barents Sea, with the aim to better understand the source terms of anthropogenic uranium in the Arctic region. Concentrations of 236U and 233U along with 137Cs, and 233U/236U atomic ratio were measured in six sediment profiles. The cumulative areal inventories of 236U and 233U obtained in this work are (3.50-12.7) × 1011 atom/m2 and (4.92-21.2) × 109 atom/m2, with averages values of (8.08 ± 2.93) × 1011 atom/m2 and (1.08 ± 0.56) × 1010 atom/m2, respectively. The total quantities of 236U and 233U deposited in the Barents Sea bottom sediments were estimated to be 507 ± 184 g and 7 ± 3 g, respectively, which are negligible compared to the total direct deposition of 236U (6000 g) and 233U (40-90 g) from global fallout in the Barents Sea. The integrated atomic ratios of 233U/236U ranging in (0.98-1.57) × 10-2 reflect the predominant global fallout signal of 236U in the Barents Sea sediments and the highest reactor-236U contribution accounts for 30 ± 14 % among the six sediment cores. The reactor-236U input in the Barents Sea sediments is most likely transported from the European reprocessing plants rather than related to any local radioactive contamination. These results provide better understanding on the source term of anthropogenic 236U in the Barents Sea, prompt the oceanic tracer application of 236U for studying the dynamics of the Atlantic-Arctic Ocean and associated climate changes. The 236U-233U benchmarked age-depth profiles seem to match reasonably well with the reported input function history of radioactive contamination in the Barents Sea, indicating the high potential of anthropogenic 236U-233U pair as a useful tool for sediment dating.
Collapse
Affiliation(s)
- Jixin Qiao
- Department of Environmental and Resource Engineering, Technical University of Denmark, DTU Risø Campus, DK-4000 Roskilde, Denmark.
| | - Hilde Elise Heldal
- Department of Contaminants and Biohazards, Institute of Marine Research, P.O.Box 1870 Nordnes, NO-5817 Bergen, Norway
| | - Peter Steier
- VERA Laboratory, Faculty of Physics - Isotope Research, University of Vienna, Währinger Straße 17, A-1090 Vienna, Austria
| |
Collapse
|
6
|
Morereau A, Jaegler H, Hain K, Steier P, Golser R, Beaumais A, Lepage H, Eyrolle F, Grosbois C, Cazala C, Gourgiotis A. Deciphering sources of U contamination using isotope ratio signatures in the Loire River sediments: Exploring the relevance of 233U/ 236U and stable Pb isotope ratios. CHEMOSPHERE 2022; 307:135658. [PMID: 35835235 DOI: 10.1016/j.chemosphere.2022.135658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 06/15/2022] [Accepted: 07/06/2022] [Indexed: 06/15/2023]
Abstract
A broad range of contaminants has been recorded in sediments of the Loire River over the last century. Among a variety of anthropogenic activities of this nuclearized watershed, extraction of uranium and associated activities during more than 50 years as well as operation of several nuclear power plants led to industrial discharges, which could persist for decades in sedimentary archives of the Loire River. Highlighting and identifying the origin of radionuclides that transited during the last decades and were recorded in the sediments is challenging due to i) the low concentrations which are often close or below the detection limits of routine environmental surveys and ii) the mixing of different sources. The determination of the sources of anthropogenic radioactivity was performed using multi-isotopic fingerprints (236U/238U, 206Pb/207Pb and 208Pb/207Pb) and the newly developed 233U/236U tracer. For the first time 233U/236U data in a well-dated river sediment core in the French river Loire are reported here. Results highlight potential sources of contamination among which a clear signature of anthropogenic inputs related to two accidents of a former NUGG NPP that occurred in 1969 and 1980. The 233U and 236U isotopes were measured by recent high performance analytical methods due to their ultra-trace levels in the samples and show a negligible radiological impact on health and on the environment. The determination of mining activities by the use of stable Pb isotopes is still challenging probably owing to the limited dissemination of the Pb-bearing material marked by the U-ore signature downstream to the former U mines.
Collapse
Affiliation(s)
- Amandine Morereau
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSE-ENV/SRTE/LRTA, SEDRE/LELI, BP 3, 13115, Saint-Paul-Lez-Durance, France
| | - Hugo Jaegler
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSE-ENV/SRTE/LRTA, SEDRE/LELI, BP 3, 13115, Saint-Paul-Lez-Durance, France
| | - Karin Hain
- Faculty of Physics, Isotope Physics, University of Vienna, Währinger Str. 17, 1090, Vienna, Austria
| | - Peter Steier
- Faculty of Physics, Isotope Physics, University of Vienna, Währinger Str. 17, 1090, Vienna, Austria
| | - Robin Golser
- Faculty of Physics, Isotope Physics, University of Vienna, Währinger Str. 17, 1090, Vienna, Austria
| | - Aurélien Beaumais
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSE-ENV/SRTE/LRTA, SEDRE/LELI, BP 3, 13115, Saint-Paul-Lez-Durance, France
| | - Hugo Lepage
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSE-ENV/SRTE/LRTA, SEDRE/LELI, BP 3, 13115, Saint-Paul-Lez-Durance, France
| | - Frédérique Eyrolle
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSE-ENV/SRTE/LRTA, SEDRE/LELI, BP 3, 13115, Saint-Paul-Lez-Durance, France
| | - Cécile Grosbois
- Université de Tours, EA 6293 Géohydrosystèmes Continentaux (GéHCO), Parc de Grandmont, 37200, Tours, Cedex, France
| | - Charlotte Cazala
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSE-ENV/SRTE/LRTA, SEDRE/LELI, BP 3, 13115, Saint-Paul-Lez-Durance, France
| | - Alkiviadis Gourgiotis
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSE-ENV/SRTE/LRTA, SEDRE/LELI, BP 3, 13115, Saint-Paul-Lez-Durance, France.
| |
Collapse
|