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Yi, Peng
Publications (10 of 11) Show all publications
Xing, S., Hou, X., Aldahan, A., Possnert, G., Shi, K., Yi, P. & Zhou, W. (2017). Water Circulation and Marine Environment in the Antarctic Traced by Speciation of I-129 and I-127. Scientific Reports, 7, Article ID 7726.
Open this publication in new window or tab >>Water Circulation and Marine Environment in the Antarctic Traced by Speciation of I-129 and I-127
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2017 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, article id 7726Article in journal (Refereed) Published
Abstract [en]

Emissions of anthropogenic I-129 from human nuclear activities are now detected in the surface water of the Antarctic seas. Surface seawater samples from the Drake Passage, Bellingshausen, Amundsen, and Ross Seas were analyzed for total I-129 and I-127, as well as for iodide and iodate of these two isotopes. The variability of I-127 and I-129 concentrations and their species (I-127(-)/(IO3-)-I-127, I-129(-)/(IO3-)-I-129) suggest limited environmental impact where ((1.15-3.15) x 10(6) atoms/L for I-129 concentration and (0.61-1.98) x 10(-11) for I-129/I-127 atomic ratios are the lowest ones compared to the other oceans. The iodine distribution patterns provide useful information on surface water transport and mixing that are vital for better understanding of the Southern Oceans effects on the global climate change. The results indicate multiple spatial interactions between the Antarctic Circumpolar Current (ACC) and Antarctic Peninsula Coastal Current (APCC). These interactions happen in restricted circulation pathways that may partly relate to glacial melting and icebergs transport. Biological activity during the warm season should be one of the key factors controlling the reduction of iodate in the coastal water in the Antarctic.

Place, publisher, year, edition, pages
Nature Publishing Group, 2017
National Category
Oceanography, Hydrology and Water Resources
Identifiers
urn:nbn:se:uu:diva-334040 (URN)10.1038/s41598-017-07765-w (DOI)000407400100013 ()28798296 (PubMedID)
Available from: 2017-11-22 Created: 2017-11-22 Last updated: 2018-01-13Bibliographically approved
Yi, P. (2013). Assessment of the relationships between iodine isotopes (I-127, I-129) and atmospheric elements in precipitation from Sweden. Journal of Radioanalytical and Nuclear Chemistry, 295(2), 1229-1234
Open this publication in new window or tab >>Assessment of the relationships between iodine isotopes (I-127, I-129) and atmospheric elements in precipitation from Sweden
2013 (English)In: Journal of Radioanalytical and Nuclear Chemistry, ISSN 0236-5731, E-ISSN 1588-2780, Vol. 295, no 2, p. 1229-1234Article in journal (Refereed) Published
Abstract [en]

In order to assess the relationships between iodine isotopes (I-127, I-129) and atmospheric elements, the concentrations of chlorine and bromine were determined using high resolution inductively coupled plasma mass spectrometry with an X SeriesII ICPMS (Thermal Electron Corporation) machine for precipitation samples collected during the period 2000-2006 at three different stations (Abisko, Uppsala and Kvidinge) in Sweden. For concentration of chlorine, Abisko in the north has the lowest average concentration, 0.6 mg/L, Kvidinge showing a little higher, 1.13 mg/L, and Uppsala exhibits as the highest concentration, 2.93 mg/L. As to bromine, the median concentration was 3.07, 3.43 and 4.73 mu g/L for station Abisko, Uppsala and Kvidinge, respectively. Chlorine and bromine show the highest correlation with I-127 in Kvidinge (r < 0.7) than those in Uppsala and Abisko. The different correlations of I-127-Cl and I-129-Cl, or I-127-Br and I-129-Br are attributed to their respective sources to the atmosphere. Furthermore, the results show that iodine isotopes (I-127, I-129) have high correlations with Cl and Br than the other atmospheric elements.

Keywords
Radioactive iodine, Iodine, Precipitation, Chlorine, Bromine
National Category
Natural Sciences
Identifiers
urn:nbn:se:uu:diva-195362 (URN)10.1007/s10967-012-1906-8 (DOI)000313713300061 ()
Available from: 2013-02-25 Created: 2013-02-25 Last updated: 2017-12-06Bibliographically approved
Yi, P., Chen, X. G., Aldahan, A., Possnert, G., Hou, X. L., Yu, Z. B., . . . Wang, B. (2013). Circulation of water masses in the Baltic Proper revealed through iodine isotopes. Applied Geochemistry, 36, 118-124
Open this publication in new window or tab >>Circulation of water masses in the Baltic Proper revealed through iodine isotopes
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2013 (English)In: Applied Geochemistry, ISSN 0883-2927, E-ISSN 1872-9134, Vol. 36, p. 118-124Article in journal (Refereed) Published
Abstract [en]

Tracer technology has been used to understand water circulation in marine systems where the tracer dose is commonly injected into the marine waters through controlled experiments, accidental releases or waste discharges. Anthropogenic discharges of I-129 have been used to trace water circulation in the Arctic and North Atlantic Ocean. Here, I-129, together with I-127, is utilized as a tracer of water pathways and circulation in the Baltic Sea through collection of seawater depth profiles. The results indicate the presence of I-129 signatures which are distinct for each water mass and provide evidence for: (1) inflow water masses through the Drogden Sill that may reach as far as the SW of the Arkona Sea, (2) a portion of North Atlantic water in the bottom of Arkona basin, (3) cyclonic upwelling which breaks through the halocline in a pattern similar to the Baltic haline conveyor belt and (4) more influx of fresher water from the Gulf of Finland and Bothnian Sea in August relative to April. These findings provide advances in labeling and understanding water pathways in the Baltic Sea.

National Category
Natural Sciences
Identifiers
urn:nbn:se:uu:diva-208363 (URN)10.1016/j.apgeochem.2013.05.014 (DOI)000323939600010 ()
Available from: 2013-09-30 Created: 2013-09-30 Last updated: 2017-12-06Bibliographically approved
Yi, P. (2013). Correlation between iodine isotopes (I-129 and I-127) species and marine parameters in the Baltic Sea. Journal of Radioanalytical and Nuclear Chemistry, 295(3), 1689-1692
Open this publication in new window or tab >>Correlation between iodine isotopes (I-129 and I-127) species and marine parameters in the Baltic Sea
2013 (English)In: Journal of Radioanalytical and Nuclear Chemistry, ISSN 0236-5731, E-ISSN 1588-2780, Vol. 295, no 3, p. 1689-1692Article in journal (Refereed) Published
Abstract [en]

Iodine is a bio-intermediate and redox-sensitive element in the oceans and understanding the relationship between transformation of iodine species promotes them as indicators of biochemical cycling in the ecosystems. To gain an insight into the transformation of iodine species, correlations between the iodine species ((IO3)-I-127 (-), I-127(-), I-129(-), (IO3)-I-129 (-)) and marine parameters (temperature, salinity, oxygen, total phosphorus, nitrate and ammonium) are assessed here for the Baltic Sea during different seasons. The datasets used cover the periods of August 2006, April 2007 and November 2009. The results indicate that the correlations between radioactive I-129, stable I-127 species and marine parameters mainly response to their respective sources as well as oceanographic environments. Also, insignificant correlations of iodine species and nutrients data (total phosphorus, nitrate and ammonium) are observed, suggesting that transformation activity of iodine species in the Baltic Sea is not directly linked to biological production.

Keywords
Iodine species, Radioactive I-129, Baltic Sea
National Category
Natural Sciences
Identifiers
urn:nbn:se:uu:diva-197052 (URN)10.1007/s10967-012-1989-2 (DOI)000314895400012 ()
Available from: 2013-03-19 Created: 2013-03-18 Last updated: 2017-12-06Bibliographically approved
Yi, P., Aldahan, A., Possnert, G., Hou, X., He, P. & Biao, W. (2013). Depth profiles of I-129 species in the Bothnian Sea. Journal of Radioanalytical and Nuclear Chemistry, 295(2), 1459-1463
Open this publication in new window or tab >>Depth profiles of I-129 species in the Bothnian Sea
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2013 (English)In: Journal of Radioanalytical and Nuclear Chemistry, ISSN 0236-5731, E-ISSN 1588-2780, Vol. 295, no 2, p. 1459-1463Article in journal (Refereed) Published
Abstract [en]

The Bothnian Sea which is located between Finland and Sweden represents an important source of fresh water to the Baltic Sea. We here present new data on the radioactive isotope I-129 species from water samples collected in December 2009 at different depths in the Bothnian Sea. Concentrations of I-129(-) (iodide) in the Bothnian Sea range from 14 x 10(8) to 32 x 10(8) atoms/L, while (IO3)-I-129 (-) (iodate) concentrations are relatively low and fluctuating at 1 x 10(8) atoms/L. For nutrients data determined in the same samples as I-129, significant correlations could be found between I-129(-) and total P, NO3-N, SiO3-Si, but rather poor with NH4-N. The correlations suggest comparable source pathway of I-129(-) and nutrient parameters, while the source of NH4-N may be different. The small amounts and negligible change of (IO3)-I-129 (-) indicate prevailing extensive reduction of iodate in the Baltic Sea.

Keywords
Radioactive iodine, Bothnian Sea, I-129, AMS, Speciation
National Category
Geochemistry
Identifiers
urn:nbn:se:uu:diva-182356 (URN)10.1007/s10967-012-1923-7 (DOI)000313713300091 ()
Available from: 2012-10-09 Created: 2012-10-09 Last updated: 2017-12-07Bibliographically approved
Yi, P., Possnert, G., Aldahan, A., Hou, X. L., Bryhn, A. C. & He, P. (2013). I-129 in the Baltic Proper and Bothnian Sea: application for estimation of water exchange and environmental impact. Journal of Environmental Radioactivity, 120, 64-72
Open this publication in new window or tab >>I-129 in the Baltic Proper and Bothnian Sea: application for estimation of water exchange and environmental impact
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2013 (English)In: Journal of Environmental Radioactivity, ISSN 0265-931X, E-ISSN 1879-1700, Vol. 120, p. 64-72Article in journal (Refereed) Published
Abstract [en]

We report here new data and a mass balance model for I-129 in the Baltic Proper and the Bothnian Sea covering the period from November-December 2009. The results showed that the general I-129 concentrations in the Bothnian Sea were two-four folds lower than in the Baltic Proper for both surface and deep water. Water exchange between the two basins based on the I-129 mass balance model suggests fluxes from the Baltic Proper to the Bothnian Sea and vice versa at 980 km(3)/y (600-1400 km(3)/y) and 1180 km(3)/y (780-1600 km(3)/y) respectively. Water retention time (residence time) in the Bothnian Sea was estimated at up to 4 years. Applying the I-129 exchange model, an estimate of total phosphorus and nitrogen inflow from the Baltic Proper to the Bothnian Sea indicates values of 20 +/- 7 x 10(3) tons/y and 300 +/- 50 x 10(3) tons/y respectively. The values for the outflow from the Bothnian Sea to the Baltic Proper hold 12 +/- 3 x 10(3) tons/y for total phosphorus and 283 +/- 55 x 10(3) tons/y for total nitrogen. These data and application of I-129 as a tracer of water masses provide information on small scale salinity changes which are vital for accurate understanding of the Baltic Sea ecosystems evolution through time.

Keywords
Radioactive iodine, Bothnian Sea, Water exchange, Baltic Sea, AMS
National Category
Natural Sciences
Identifiers
urn:nbn:se:uu:diva-200033 (URN)10.1016/j.jenvrad.2013.01.009 (DOI)000317445200010 ()
Available from: 2013-05-23 Created: 2013-05-20 Last updated: 2017-12-06Bibliographically approved
Yi, P., Chen, X. G., Bao, D. X., Qian, R. Z., Aldahan, A., Tian, F. Y., . . . Wang, B. (2013). Model simulation of inflow water to the Baltic Sea based on I-129. Applied Radiation and Isotopes, 82, 223-231
Open this publication in new window or tab >>Model simulation of inflow water to the Baltic Sea based on I-129
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2013 (English)In: Applied Radiation and Isotopes, ISSN 0969-8043, E-ISSN 1872-9800, Vol. 82, p. 223-231Article in journal (Refereed) Published
Abstract [en]

The semi-enclosed Baltic Sea represents a vital economic and recreational resource for more than 90 million people inhabiting its coasts. Extensive contamination of this sea by a variety of anthropogenic pollutants has raised the concern of the people in the region. Quantifying seawater inflow is crucial for estimating potential environmental risks as well as to find the best remedial strategy. We present here a model to estimate water inflow from the North Sea to the Baltic Sea by utilizing 1291 as a tracer. The results predicted inflow range of 230-450 km(3)/y with best fit value around 330 km(3)/y from the North Sea to the Baltic Sea during 1980-1999. Despite limited time series data on I-129, the model presented here demonstrates a new management tool for the Baltic Sea to calculate inflow water compared to conventional methods (such as salinity, temperature and hydrographic models). 

Keywords
Radioisotopes, Water flow, Flux, Baltic Sea, Iodine, Mathematical models
National Category
Natural Sciences
Identifiers
urn:nbn:se:uu:diva-216755 (URN)10.1016/j.apradiso.2013.07.034 (DOI)000328804000035 ()
Available from: 2014-01-24 Created: 2014-01-24 Last updated: 2017-12-06Bibliographically approved
Yi, P., Aldahan, A., Possnert, G., Hou, X. L., He, P. & Wang, B. (2013). Seasonal variation of I-129 species in the Baltic Proper. Journal of Radioanalytical and Nuclear Chemistry, 295(3), 1797-1801
Open this publication in new window or tab >>Seasonal variation of I-129 species in the Baltic Proper
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2013 (English)In: Journal of Radioanalytical and Nuclear Chemistry, ISSN 0236-5731, E-ISSN 1588-2780, Vol. 295, no 3, p. 1797-1801Article in journal (Refereed) Published
Abstract [en]

Iodine speciation plays a significant role in iodine volatilizing into atmosphere from the seas, as well as serving as a biological indicator. Despite this importance, the data on iodine species revealed inconclusive evidence of what factors controlling speciation transformation. We here present new data on profiles of I-129 speciation in the Baltic Proper during November 2009. Along with the two earlier investigations (August 2006 and April 2007), an assessment of seasonal variation of I-129 species is presented. The results show that, due to the anoxic nature of Baltic Proper, presence of (IO3)-I-129 (-) in the Baltic Proper does not follow an obvious seasonal cycle, as the case with I-129(-). Concentrations of I-129(-) in the Baltic Proper exhibit higher values in summer than the other two seasons (spring and winter), which might be associated with degrading of organic matter and release from sediment to water column that is more pronounced during summer. I-129(-) in surface water from the three seasons does not reflect the release function from the reprocessing facilities during the period April 2007 to November 2009. Consequently variability of I-129(-) in surface seawater of the Baltic Proper depends, to some extent, on local physical as well as biochemical conditions.

Keywords
Radioactive I-129 species, Baltic Proper, Iodine
National Category
Natural Sciences
Identifiers
urn:nbn:se:uu:diva-197053 (URN)10.1007/s10967-012-2099-x (DOI)000314895400027 ()
Available from: 2013-03-18 Created: 2013-03-18 Last updated: 2017-12-06Bibliographically approved
Yi, P., Aldahan, A., Possnert, G., Hou, X. L., Hansen, V. & Wang, B. (2012). I-127 and I-129 Species and Transformation in the Baltic Proper, Kattegat, and Skagerrak Basins. Environmental Science and Technology, 46(20), 10948-10956
Open this publication in new window or tab >>I-127 and I-129 Species and Transformation in the Baltic Proper, Kattegat, and Skagerrak Basins
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2012 (English)In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 46, no 20, p. 10948-10956Article in journal (Refereed) Published
Abstract [en]

Occurrence of anthropogenic I-129 in seawater has provided invaluable information about water circulation and exchange rates, but results on I-129 species (iodide and iodate) are limited and only available for surface water. We here present the first extensive results on I-129 and I-127 species in samples of seawater depth profiles, which were collected in August 2006 and April 2007 in the Skagerrak, Kattegat, and Baltic Proper. The results expose <= 10% annual reduction of iodate as I-129 is transported from the English Channel along the Dutch coast and German Bight into the Skagerrak and Kattegat. The results also suggest strong variability between surface and bottom seawater with respect to the predominant iodine species. Distribution of iodide and iodate of both I-127 and I-129 in the Kattegat mainly reflects water mixing process rather than speciation transformation. In water of the Baltic Proper, high I-127(-)/(IO3-)-I-127 and I-129-/(IO3-)-I-129 values suggest effective reduction of iodate with a maximum rate of 8 x 10(-7) ((IO3-)-I-127) and 6 x 10(-14) ((IO3-)-I-129) (g/m(3).day). The reduction process of iodate seems to be related to decomposition of organic matter and photochemically induced reactions.

National Category
Natural Sciences
Identifiers
urn:nbn:se:uu:diva-187716 (URN)10.1021/es301979r (DOI)000309805000015 ()
Available from: 2012-12-11 Created: 2012-12-10 Last updated: 2017-12-07Bibliographically approved
Yi, P. (2012). Iodine Isotopes (129I and 127I) in the Baltic Sea  : Tracer applications & environmental impact. (Doctoral dissertation). Uppsala: Acta Universitatis Upsaliensis
Open this publication in new window or tab >>Iodine Isotopes (129I and 127I) in the Baltic Sea  : Tracer applications & environmental impact
2012 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

129I is a radioactive isotope (T1/2= 15.7 million years) produced through natural and anthropogenic pathways, but the anthropogenic production is presently dominating the Earth’s surface environments. Sparse data from previous investigations in the Baltic Sea clearly indicated the occurrence of 129I at levels 3-4 orders higher than natural pre-atomic era (before 1940) without comprehensive evaluation of distribution and inventory. In this thesis extensive data on the distribution and inventory of iodine isotopes, 129I and 127I, and their species in waters of the Baltic Sea, Kattegat and Skagerrak are presented and used for estimation of water masses exchange and impact on the environment.  To fulfill these objectives seawater samples were collected in August 2006 and April 2007 in the Baltic Proper, Kattegat and Skagerrak as well as in December 2009 in the Bothnian Sea. After elaborative chemical separation of total iodine and iodine species, the analysis was performed using ICP-MS for 127I and AMS for 129I. The results reveal considerable differences in 129I concentration in terms of spatial and temporal variability and expose relatively high concentrations in the deep waters. Inventory estimates show higher amounts of 129I in August 2006 (24.2 ±15.4 kg) than in April 2007 (14.4± 8.3 kg) within the southern and central Baltic Proper, whereas almost a constant inventory is found in the Kattegat Basin. Relatively high 127I-/127IO3- and 129I-/129IO3- values in water of the Baltic Proper suggest effective reduction of iodate at a maximum rate of  8×10-7 (127IO3-) and 6×10-14 (129IO3-) (g/m3.day). The combination of 129I and 127I as tracers of water circulation in the Baltic Sea suggest that upwelling deep basinal water occurs into the surface along the Gotland deep and intrusion of North Atlantic water into southern Baltic. Furthermore, 129I-based model inventory reveals inflow of 330 km3/y (230-450 km3/y) water from the Kattegat into the Baltic Proper. Water exchange between the Baltic Proper and the Bothnian Sea and vice versa is estimated at 980 km3/y (600-1400 km3/y) and 1180 km3/y (780-1600 km3/y) respectively. Finally, an environmental assessment of radioactivity associated with 129I burden in the Baltic Sea region is discussed.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2012. p. 58
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 980
Keywords
radioactive 129I, stable 127I, AMS, iodine species, nuclear reprocessing facilities, tracers, Baltic Sea, circulation, water exchange, environmental impact
National Category
Earth and Related Environmental Sciences
Identifiers
urn:nbn:se:uu:diva-182357 (URN)978-91-554-8494-1 (ISBN)
Public defence
2012-11-23, Axel Hambergsalen, Villvägen 16, Uppsala, 10:00 (English)
Opponent
Supervisors
Available from: 2012-10-31 Created: 2012-10-09 Last updated: 2013-01-23Bibliographically approved
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