Endre søk
Begrens søket
1 - 5 of 5
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Treff pr side
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
Merk
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 1. He, Peng
    et al.
    Aldahan, Ala
    Possnert, Goran
    Hou, Xiaolin
    Temporal Variation of Iodine Isotopes in the North Sea2014Inngår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 48, nr 3, s. 1419-1425Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Monitoring temporal variability of I-129 in the North Sea, a relatively large reservoir of radioactive discharges from the nuclear fuel reprocessing facilities, is vital for the environmental situation in the region. New information on concentration levels and distribution of I-129 and I-127 and their species forms (iodide and iodate) are gained here through sampling of surface water in 2010. The results show generally large spatial and temporal (compared to data from 2005) fluctuations of total I-129 and I-127, and iodide and iodate. In samples south of 53 degrees N, the level of I-127(-) in 2010 was generally comparable or higher than in 2005. The results also show total I-129 concentrations comparable in the south, but 2-8 times lower in the north, to the analyses made in 2005. Different from total I-129, the I-129(-)/(IO3-)-I-129 values in the northern part were 2 times higher in 2010 than values observed in 2005. These variations in total I-129 and I-127 and their species are related to coastal water offshore propagation and surface currents that are linked to long-term and seasonal climatic changes over the North Atlantic and North Sea. Inventory estimation shows that >90% of I-129 resides in the Southern and German Bights, which also suggests negligible contribution from the Sellafield facility discharges when compared with that from the La Hague. Variability in discharge rate from La Hague may also affect the distribution patterns of I-129 in the North Sea on the monthly scale.

  • 2. He, Peng
    et al.
    Hou, Xiaolin
    Aldahan, Ala
    Possnert, Goran
    Radioactive I-129 in surface water of the Celtic Sea2014Inngår i: Journal of Radioanalytical and Nuclear Chemistry, ISSN 0236-5731, E-ISSN 1588-2780, Vol. 299, nr 1, s. 249-253Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Relatively large amounts of radioactive iodine I-129 (T (1/2) = 15.7 Ma) have been documented in seawater such as the English Channel, the Irish Sea and the North Sea. Data on the concentration of the iodine isotopes in waters of the Celtic Sea are missing. Aiming to provide first I-129 data in the Celtic Sea and compare them with levels in the other close-by seawater bodies, surface seawater samples were analyzed for the determination of I-127 and I-129 concentrations. The results revealed a high level of I-129 in these waters and suggest strong influence by liquid discharges from La Hague and Sellafield reprocessing facilities. I-127 concentrations are rather constant while the I-129/I-127 ratio reaches up to 2.8 x 10(-8) (ranging from 10(-10) to 10(-8)), which is 2-4 orders of magnitude higher than pre-nuclear era natural level. Transport of I-129 to the Celtic Sea is difficult to depict accurately since available data are sparse. Most likely, however, that discharges originated from La Hague may have more influence on the Celtic Sea I-129 concentrations than the Sellafield. Comprehensive surface water and depth profiles I-129 data will be needed in the future for assessment of environmental impact in the region.

  • 3. He, Peng
    et al.
    Hou, Xiaolin
    Aldahan, Ala
    Possnert, Goran
    Yi, Peng
    Iodine isotopes species fingerprinting environmental conditions in surface water along the northeastern Atlantic Ocean2013Inngår i: Scientific Reports, E-ISSN 2045-2322, Vol. 3, artikkel-id 2685Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Concentrations and species of iodine isotopes (I-127 and I-129) provide vital information about iodine geochemistry, environmental conditions and water masses exchange in oceans. Despite extensive investigations of anthropogenic I-129 in the Arctic Ocean and the Nordic Seas, concentrations of the isotope in the Atlantic Ocean are, however, still unknown. We here present first data on I-129 and I-127, and their species (iodide and iodate) in surface water transect along the northeastern Atlantic between 30 degrees and 50 degrees N. The results show iodate as the predominant species in the analyzed marine waters for both I-127 and I-129. Despite the rather constant ratios of I-127(-)/(IO3-)-I-127, the I-129(-)/(IO3-)-I-129 values reveal variations that apparently response to sources, environmental conditions and residence time. These findings provide a new tracer approach that will strongly enhance the application of anthropogenic I-129 in ocean environments and impact on climate at the ocean boundary layer.

  • 4.
    He, Peng
    et al.
    Chengdu Univ Technol, Sch Ecol & Environm, Chengdu 610059, Peoples R China.;Chengdu Univ Technol, State Key Lab Geohazard Prevent & Geoenvironm Pro, Chengdu 610059, Peoples R China..
    Pang, Hongying
    Chengdu Univ Technol, Sch Ecol & Environm, Chengdu 610059, Peoples R China..
    Yang, Zheng
    Chengdu Univ Technol, Sch Ecol & Environm, Chengdu 610059, Peoples R China..
    Li, Sihong
    Chengdu Univ Technol, Sch Ecol & Environm, Chengdu 610059, Peoples R China..
    Huang, Yi
    Chengdu Univ Technol, Sch Ecol & Environm, Chengdu 610059, Peoples R China.;Chengdu Univ Technol, State Key Lab Geohazard Prevent & Geoenvironm Pro, Chengdu 610059, Peoples R China..
    Hou, Xiaolin
    Tech Univ Denmark, Dept Environm & Resource Engn, Ris Campus, DK-4000 Roskilde, Denmark.;Chinese Acad Sci, Xian AMS Ctr, Inst Earth Environm, State Key Lab Loess & Quaternary Geol, Xian 710061, Peoples R China..
    Possnert, Göran
    Uppsala universitet, Tandemlaboratoriet.
    Zheng, Xuefeng
    Sichuan Jinmei Environm Protect Co Ltd, Chengdu, Peoples R China..
    Pei, Xiangjun
    Chengdu Univ Technol, Sch Ecol & Environm, Chengdu 610059, Peoples R China.;Chengdu Univ Technol, State Key Lab Geohazard Prevent & Geoenvironm Pro, Chengdu 610059, Peoples R China..
    Aldahan, Ala
    United Arab Emirates Univ, Dept Geosci, POB 15551, Al Ain, U Arab Emirates..
    127I and 129I species in the English Channel and its adjacent areas: uncovering impact on the isotopes marine pathways2022Inngår i: Water Research, ISSN 0043-1354, E-ISSN 1879-2448, Vol. 225, artikkel-id 119178Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Radioactive iodine-129 has been released from the La Hague nuclear fuel reprocessing facility (NRF) into the English Channel, but the distribution and transformation of the isotope species, and environmental consequences have not been fully characterized in the Channel. Here we present data on iodine isotopes (129I and 127I) species in surface water of the English Channel and the southern Celtic Sea. Compared to 127I species, the concentrations of 129I- and 129IO3- show more variations, but iodate is the major species for both 129I and 127I. Our data provide new information regarding iodide-iodate inter-conversion showing that water dilution and mixing are the main factors affecting the 127I and 129I species distribution in the Channel. Some reduction of iodate occurs within the English Channel and mainly in the west part because of biotic processes. The 129I species transformation is overall insignificant, especially in the eastern Channel, where a constant value of 129IO3- /129I is observed, which might characterize the La Hague wastewater signal. In the Celtic Sea, oxidation of iodide can be traced by 127I and 129I species. On a larger scale,129I generally experienced an oxidation process in the Atlantic Ocean, while in the coast of shallow shelf seas, new produced 129I- can be identified, especially in the German Bight and the Baltic Sea. The data of 129I species in the English Channel can provide estimate of redox rates in a much broader marine areas if the transit time of 129I from La Hague is well-defined. Furthermore, estimate of inventories for 129I and its species in the Channel, and fluxes of 129I species from the English Channel to the North Sea add important information to the geochemical cycle of 129I.

  • 5. Xing, Shan
    et al.
    Hou, Xiaolin
    Aldahan, Ala
    Possnert, Goran
    Shi, Keliang
    Yi, Peng
    Zhou, Weijian
    Iodine-129 in Snow and Seawater in the Antarctic: Level and Source2015Inngår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 49, nr 11, s. 6691-6700Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Anthropogenic I-129 has been released to the environment in different ways and chemical species by human nuclear activities since the 1940s. These sources provide ideal tools to trace the dispersion of volatile pollutants in the atmosphere. Snow and seawater samples collected in Bellingshausen, Amundsen, and Ross Seas in Antarctica in 2011 were analyzed for I-129 and I-127, including organic forms; it was observed that I-129/I-127 atomic ratios in the Antarctic surface seawater ((6.1-13) x 10(-12)) are about 2 orders of magnitude lower than those in the Antarctic snow ((6.8-9.5) x 10(-1)0), but 4-6 times higher than the prenuclear level (1.5 x 10(-12)), indicating a predominantly anthropogenic source of I-129 in the Antarctic environment. The I-129 level in snow in Antarctica is 24 orders of magnitude lower than that in the Northern Hemisphere, but is not significantly higher than that observed in other sites in the Southern Hemisphere. This feature indicates that I-129 in Antarctic snow mainly originates from atmospheric nuclear weapons testing from 1945 to 1980; resuspension and re-emission of the fallout I-129 in the Southern Hemisphere maintains the I-129 level in the Antarctic atmosphere. I-129 directly released to the atmosphere and re-emitted marine discharged I-129 from reprocessing plants in Europe might not significantly disperse to Antarctica.

1 - 5 of 5
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf