Thesis for the Degree of Doctor of Philosophy - DTU Orbit

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The concentrations of 129 I and 127 I and ratios of 129 I/ 127 I in the samples are listed in Tables 1-3. The concentrations of stable iodine ( 127 I, Tables 1-3) vary from 95 ug/g dry weight to 180 ug/g dry weight with a mean of 140 ug/g dry weight for samples collected from Bornholm in the Baltic Sea, 96 ug/g dry weight to 740 ug/g dry weight with a mean of 402 ug/g dry weight for samples collected from Klint in the southern Kattegat and 210 ug/g dry weight to 1100 ug/g dry weight with a mean of 505 ug/g dry weight for samples collected from Rømø in the North Sea. The monthly results at Rømø and Klint indicate that an increase of 127 I in Fucus occur mostly during autumn – winther (Figures 5 and 6). The data reveal that concentrations of I-129 in samples from Rømø are approximately one order of magnitude (Table 1) higher relative to samples from Bornholm (Table 3) during the period 2004 – 2010. The iodine - 129 concentrations in seaweed collected from Rømø from 2004 to 2010 vary between 1.8×10 -10 to 1 ×10 -9 while at Klint from 2002 to 2010 concentrations vary between 8.5×10 -12 to 2.5 ×10 - 10 dry weight and at Bornholm from 2002 to 2010 vary from 9.9×10 -12 to 1.7×10 -11 . The results of the 129 I/ 127 I ratios for all samples are shown in Figures 2-4. The 129 I/ 127 I ratio ranged between 6.9 ×10 -7 - 1.9 ×10 -6 for seaweed from Rømø, 6.3 ×10 -8 - 7.1 ×10 -7 for seaweed collected from Klint and 6.0 ×10 -8 - 1.2 ×10 -7 for seaweed collected from Bornholm. 4 Discussion Despite the limited number of sampling sites used here the concentrations of stable iodine ( 127 I) vary significantly (Tables 1-3 and Figures 2-4) with the lowest values founded at Bornholm in the Baltic Sea were 140 ± 40 ug/g (1 std, n=5) dry weight was obtained. At Romø and Klint the I-127 concentrations (505 ± 230µg/g and 402 ± 190µg/g) were more or less the same. Large seasonal variations of stable iodine in seaweed samples have been reported before (Hou & Yan, 1998, Hou et al., 2000; Sash et al., 2005; Keogh et al., 2007) and are viewed as a result of variable uptake over the various physical parts of the plant, seasonal variations as well as due to slightly different sampling locations with different 6
salinities in the same area. Apart from these variables it may also be anticipated that the relative proportions of the two iodine seawater species, iodide and iodate, may influence the uptake in Fucus. We have earlier shown (Hou et al., 2007; Hansen et al., 2011, Yi et al., 2012 in work) that the dominating iodate species gradually is reduced to iodide while moving from the North Sea into the Baltic Sea. Alternatively other biochemical factors such as differences in the amount of dissolved organic carbon or seawater composition (eg. salinity) between the locations may be responsible for the observed changes. It is well known (Hansen et al., 2011b) that iodine sticks to dissolved organic matter and may thus be less prone to accumulate in seaweed. Concentrations of DOC in the southern Baltic Sea are typically 1-2 orders of magnitude higher than in Kattegat and North Sea. In contrast to stable iodine the concentrations of anthropogenic iodine (Iodine-129) are orders of magnitude higher in samples collected from Rømø in the North Sea compared with samples collected from Baltic Sea and southern Kattegat. Our results are in agreement with previously published data (Hou et al, 2000) supporting a clearly decreasing trend of iodine - 129 in Fucus from Klint to Bornholm. These results are expected given the proximity of Rømø to the La Hague reprocessing plant and previous observations on coastal currents in the south part of the North Sea. Dahlgaard et al (1995) estimated that roughly 10% of the La Hague (English Chanel) and 2% of the Sellafield (Irish Sea) releases are transported into Kattegat. The relative decrease of seawater iodine-129 moving from the North Sea, Skagerrak towards the south parts of the Baltic Sea indicated by Hou et al., (2007) and Yi et al., (2011) seems to be partly confirmed by the iodine-129 level in Fucus (Tables 1-3). Due to the large variations of 129 I concentrations, the 129 I/ 127 I ratio is a more reliable index of the level of 129 I enrichment in seaweed (Hou et al., 2000; Keogh et al., 2007). It is important to mention that the ratios of 7
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Chemical Speciation Analysis and En
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Thesis for the Degree of Doctor of
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Abstract This thesis deals with che
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environment since they reflect the
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organiske jodformer. Adsorption af
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None of this would have been possib
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Abbreviations and acronyms b+ - pos
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3.1 Analytical Development………
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Table 1 Some properties of iodine P
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In soils/sediments iodine occurs as
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Table 2 Nuclear properties of iodin
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Liquid scintillation counting (LSC)
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The bioavailability of radioactive
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data (Englund et al., 2010; Hou et
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2. Analytical procedures used in th
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2.3 Quantification of total iodine
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Fig. 5 Quantification of total iodi
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iodate were measured by counting 12
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Fig. 6 Sequential extraction proced
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a Fig. 8 Calibration curve for (a)
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experiment was subjected to combust
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Table 7 Adsorption of iodine specie
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numbers 11-14), which is about the
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marine environment from nuclear fue
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127 I - (ppb) 127 IO3 - (ppb) a b 1
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Although the oxygen concentration d
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129 I TBq 2,00E+00 1,80E+00 1,60E+0
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• Adsorption of iodine species on
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Reference Aldahan A, Kekli A, Possn
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Fuge R& Johnson C. 1986. The geoche
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Lo´pez-Gutie´rrez JM, Garcı ´a-
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Shinohara K. 2004. Measurement and
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http://www.irsn.fr/EN/news/Document
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Review Analytica Chimica Acta 632 (
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Table 1 Nuclear properties and prod
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Fig. 2. Liquid discharges of 129 I
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Fig. 5. Schematic diagram and pictu
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129 I in iodide and iodate is then
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Fig. 8. Diagram of air sampler for
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Fig. 10. Iodine L3-edge (a) and K-e
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analysis of 129 I in water sample a
Page 83 and 84: Yi P, Aldahan A, Hansen V, Possnert
Page 85 and 86: FIGURE 1. Sampling sites (the red s
Page 87 and 88: FIGURE 3. Horizontal distribution o
Page 89 and 90: FIGURE 5. Time series data of 129 I
Page 91 and 92: Environmental Science & Technology
Page 93 and 94: prepared using KI and KIO3. No diff
Page 95 and 96: of their contribution to the Baltic
Page 97 and 98: Fig. S-1 Sampling sites (the red so
Page 99 and 100: Fig. S-3 Vertical distribution of I
Page 101 and 102: Fig. S-5 Marine discharges function
Page 103 and 104: Fig.S-7 Relationship between I-129
Page 105 and 106: Table S-1 Results of I-129 and I-12
Page 107 and 108: S17
Page 109 and 110: Paper III Hansen,V., Yi, P., Hou, X
Page 111 and 112: conversion process between iodide a
Page 113 and 114: Table 1 Analytical results of 129 I
Page 115 and 116: August April I-129 iodide ( 10 8 at
Page 117 and 118: References Aldahan A, Kekli A, Poss
Page 119 and 120: Partition of iodine ( 129 I and 127
Page 121 and 122: Norway (Table 1). CTD-casts with ox
Page 123 and 124: 5. Discussion 5.1. Separation of hu
Page 125 and 126: In the present study 40e60% of 129
Page 127 and 128: Hutta, M., Gora, R., 2003. Novel st
Page 129 and 130: Analysis of 129 I and 127 I in arch
Page 131 and 132: et al., 2002). Due to the fact that
Page 133: espectively. The iodine was leached
Page 137 and 138: North Sea. 129 I/ 127 I ratios in w
Page 139 and 140: Table 2 Analytical results of 129-I
Page 141 and 142: 129 I/ 127 I 1,40E-07 1,20E-07 1,00
Page 143 and 144: References Aldahan A, Englund E, Po
Page 145 and 146: O’Dowd, C.; Jimenez, J. L.; Bahre
Page 147 and 148: Iodine ( 129 I and 127 I) speciatio
Page 149 and 150: water in winter by molecular oxygen
Page 151 and 152: 0.2 M KNO3. The effluent and the wa
Page 153 and 154: maximum values is at 0.03-0.06×10
Page 155 and 156: into the English Channel from the L
Page 157 and 158: References Aldahan A, Kekli A, Poss
Page 160 and 161: Risø-PhD-81(EN)
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Thesis for the Degree of Doctor of Philosophy - DTU Orbit

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