Thesis for the Degree of Doctor of Philosophy - DTU Orbit

More documents

Recommendations

Info

Methods Chemical separation and measurement All water samples used for iodine isotopes analyses, were passed through a 0.45µm membrane filter and stored in cold and dark room until analysis. The extraction of iodine from seawater was based on the method by (1-2). 20 ml seawater was taken to a separation funnel and 0.2 ml of 200 Bq/ml 125 I - (NaI) as chemical yield tracer and 2.0 mg of stable iodine (Woodward Iodine Company, USA) as a carrier were added. After addition of 0.2 mL of 2.0 M NaHSO3, 3 M HNO3 was added to adjust pH1-2 to convert all inorganic iodine to iodide. 10 ml CCl4 and NaNO2 were added to oxidize iodide to iodine, which was extracted to CCl4 phase by shaking. The CCl4 phase was separated and transferred to another separation funnel, 10 ml water and 0.1 ml of 0.1 M NaHSO3 were added to back-extract iodine to water phase, and the extraction procedure was repeated. Finally, iodine (iodide) was precipitated as AgI by adding AgNO3. Blank samples were prepared in the same way as described above for the seawater samples. After drying, AgI precipitate was ground and mixed with niobium, which was then pressed into copper holder for 129 I measurement. 129 I was measured by AMS system (the Pelletron NEC machine) in Tandem Laboratory at Uppsala University using NIST SRM 4949C 129 I as a standard. The processing blanks 129 I/ 127 I values were 1.5 ± 0.5 × 10 -13 , which is more than 2 orders of magnitude lower than the value in the samples . . Total analytical uncertainty for 129 I/ 127 I ratio is normally less than 10 %. For the determination of 127 I from seawater, the samples were diluted for 20 times using 0.015 M NH4OH and Cs + as (CsCl) was added as an internal standard to the concentration of 2.0 ng/ml. The concentration of iodine was measured using an X Series II ICP-MS (Thermal Electron Corporation), under hot plasma conditions, with the Xt interface. Iodine standard solutions were S2
prepared using KI and KIO3. No difference of signal intensity between Iodide and iodate was observed. The detection limit, calculated as 3SD, of blanks was 0.27 nM. Data plotting The depth distribution of 129 I was plotted using ODV (Ocean Data View) software, which is specific for graphical display of gridded data. VG Gridding algorithm was implemented to construct the rectangular grid and the same value 100 per mile was set for grid-spacing along X and Y directions. Concentrations of 129 I, 127 I, oxygen, salinity and 129 I/ 127 I for every grid point were calculated by a weighted-averaging scheme. This procedure allowed resolving dense data coverage area and at the same time provides acceptable representation for regions with sparse data. Model description The simple model used consists of four compartments, seawater inflow and outflow, freshwater tributary and sedimentation (Figure S-8). It is achieved on a yearly basis and performs from 1968 to 2006 as liquid emission from Sellafield nuclear reprocessing facility was insignificant during the period of 1952 to 1965. The natural inventory of 3.2× 10 -4 kg for the Baltic Sea (3) was adapted into the model as initial value and 10% analyzes error for iodine concentration is considered in the final results. The detail descriptions for each of dynamic process are illustrated in the following text. Seawater inflow 129 I carried by seawater inflowing to the Baltic Sea has been estimated by using available historical concentrations in surface water of site 14 (Figure S-1) in the Kattegat as a function of accumulated mass of discharges from Sellafield and La Hague (Figure S-7). This relationship S3
Page 1 and 2:
Chemical Speciation Analysis and En
Page 3 and 4:
Thesis for the Degree of Doctor of
Page 5 and 6:
Abstract This thesis deals with che
Page 7 and 8:
environment since they reflect the
Page 9 and 10:
organiske jodformer. Adsorption af
Page 11 and 12:
None of this would have been possib
Page 13 and 14:
Abbreviations and acronyms b+ - pos
Page 15 and 16:
3.1 Analytical Development………
Page 17 and 18:
Table 1 Some properties of iodine P
Page 19 and 20:
In soils/sediments iodine occurs as
Page 21 and 22:
Table 2 Nuclear properties of iodin
Page 23 and 24:
Liquid scintillation counting (LSC)
Page 25 and 26:
The bioavailability of radioactive
Page 27 and 28:
data (Englund et al., 2010; Hou et
Page 29 and 30:
2. Analytical procedures used in th
Page 31 and 32:
2.3 Quantification of total iodine
Page 33 and 34:
Fig. 5 Quantification of total iodi
Page 35 and 36:
iodate were measured by counting 12
Page 37 and 38:
Fig. 6 Sequential extraction proced
Page 39 and 40:
a Fig. 8 Calibration curve for (a)
Page 41 and 42: experiment was subjected to combust
Page 43 and 44: Table 7 Adsorption of iodine specie
Page 45 and 46: numbers 11-14), which is about the
Page 47 and 48: marine environment from nuclear fue
Page 49 and 50: 127 I - (ppb) 127 IO3 - (ppb) a b 1
Page 51 and 52: Although the oxygen concentration d
Page 53 and 54: 129 I TBq 2,00E+00 1,80E+00 1,60E+0
Page 55 and 56: • Adsorption of iodine species on
Page 57 and 58: Reference Aldahan A, Kekli A, Possn
Page 59 and 60: Fuge R& Johnson C. 1986. The geoche
Page 61 and 62: Lo´pez-Gutie´rrez JM, Garcı ´a-
Page 63 and 64: Shinohara K. 2004. Measurement and
Page 65 and 66: http://www.irsn.fr/EN/news/Document
Page 67 and 68: Review Analytica Chimica Acta 632 (
Page 69 and 70: Table 1 Nuclear properties and prod
Page 71 and 72: Fig. 2. Liquid discharges of 129 I
Page 73 and 74: Fig. 5. Schematic diagram and pictu
Page 75 and 76: 129 I in iodide and iodate is then
Page 77 and 78: Fig. 8. Diagram of air sampler for
Page 79 and 80: Fig. 10. Iodine L3-edge (a) and K-e
Page 81 and 82: 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: Environmental Science & Technology
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 and 134: espectively. The iodine was leached
Page 135 and 136: salinities in the same area. Apart
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)
show all

Thesis for the Degree of Doctor of Philosophy - DTU Orbit

Create successful ePaper yourself

Delete template?

Save as template?