Thesis for the Degree of Doctor of Philosophy - DTU Orbit

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In this work two potential getters were evaluated for their ability to sorb iodide, iodate and organic iodine from freshwater and seawater. These materials include activated charcoal washed with double distilled water and/or ethanol to remove fine carbon particles and DEAE 32 cellulose, an anion exchange resin widely used in protein purification/separation. The adsorption capacity of activated charcoal and DEAE 32 cellulose as a function of iodide and iodate concentrations, different pH, contact time, amount of activated charcoal and amount of DEAE 32 cellulose was investigated. A volume of 200 mL of Whatman 540 filtered water, previously analyzed for total iodine using direct injection ICP-MS, was mixed with 100 Bq of 125 I tracer and 5g wet activated charcoal or DEAE 32 cellulose and stirred at room temperature for 2h. The mixture was then filtered through a Whatman 540 paper filter and the concentration of total iodine in the filtrate was measured by ICP-MS. After adsorption of iodine species the activated charcoal and DEAE 32 cellulose was subjected to alkaline digestion or combustion at 900 0 C. For alkaline digestion the solid sorbent from the batch experiment was mixed with 5mL of 3M NaOH and the mixture was dried at 70–80 0 C, and then burnt and ashed at 350 0 C for 30’ and 650 0 C for 3h, respectively. The iodine was leached (1h) from the ashed samples with double distilled water at 100 0 C. The leached solution was filtered through a Whatman 540 filter and the iodine was separated from the matrix by extraction and back-extraction with CHCl3 and KHSO3 solution. The chemical yield of iodine-125 in the whole procedure was measured using a NaI γ-detector. 2.4 Quantification of total iodine in freshwater by K2S2O8 oxidation of iodine organic matter (unpublished results). An alternative way of being able to include the aquatic organic bound iodine-129 fraction into total iodine concentrations would be to try and remove iodine from the organic material or try to destroy it. Assays were therefore carried out to destroy organic iodine-129 in water samples by oxidation, using K2S2O8 or a mixture of K2S2O8/NaClO. As previously (see 2.3) the 127 I was used in all conducted experiments presented in this section. The experiments were aimed at estimating the total concentration of iodine-129 in freshwater samples by destroying the organic iodine followed by reduction of all iodine species to iodide and precipitation as AgI after adding silver nitrate. The applied procedure is presented in Figure 5. 30
Fig. 5 Quantification of total iodine in freshwater by K2S2O8 oxidation of iodine organic matter The AgI were separated from the sample by centrifugation and the total amount of iodine-127 remaining in the supernatant was measured using ICP-MS. After determining the inorganic 129 I species (iodide and iodate) using anion exchange chromatography (see 2.7), the amount of organic iodine-129 encountered in a studied water sample will be calculated by subtracting the inorganic iodine from total iodine determined after oxidation of iodine organic matter. In the present work the efficiency of different oxidants as a function of the amount of iodine organic matter in the water sample was investigated. The total concentration of iodine in the original studied lake water sample was 9.2 ppb as determined by direct analysis of the water using ICP-MS. A volume of 200 mL of Whatman 540 filtered fresh water was mixed with 0.5g of K2S2O8. Iodine associated to organic matter was supplied to the sample water by adding iodine humic substances extracted from soil (see the extraction procedure in paper IV) or low molecular weight organic iodine extracted from seaweed (Sash et al., 2005). The mixture was stirred for 2h at room temperature. The iodine species was then reduced to iodide by adding 1mL of 1M K2S2O5 at a pH 1-2 with HNO3.The iodide was separated from the matrix by adding 1-2mL of 1M AgNO3 and the solution was stirred at room temperature for 30 minutes. The precipitate is separated by centrifugation at 3000 × g for 30 minutes. 2.5 A method for quantification of total iodine (organic and inorganic species) in freshwater samples by NaClO and NaOH oxidation of iodine organic species (in Paper VI). A simple method for analysis of total, (organic and inorganic species) 129 I in fresh water was developed. The method is based on oxidation of 31
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: 2.3 Quantification of total iodine
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
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Environmental Science & Technology
Page 93 and 94:
prepared using KI and KIO3. No diff
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of their contribution to the Baltic
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Fig. S-1 Sampling sites (the red so
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Fig. S-3 Vertical distribution of I
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Fig. S-5 Marine discharges function
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Fig.S-7 Relationship between I-129
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Table S-1 Results of I-129 and I-12
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S17
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Paper III Hansen,V., Yi, P., Hou, X
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conversion process between iodide a
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Table 1 Analytical results of 129 I
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August April I-129 iodide ( 10 8 at
Page 117 and 118:
References Aldahan A, Kekli A, Poss
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Partition of iodine ( 129 I and 127
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Norway (Table 1). CTD-casts with ox
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5. Discussion 5.1. Separation of hu
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In the present study 40e60% of 129
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Hutta, M., Gora, R., 2003. Novel st
Page 129 and 130:
Analysis of 129 I and 127 I in arch
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et al., 2002). Due to the fact that
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espectively. The iodine was leached
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salinities in the same area. Apart
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North Sea. 129 I/ 127 I ratios in w
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Table 2 Analytical results of 129-I
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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
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water in winter by molecular oxygen
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0.2 M KNO3. The effluent and the wa
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maximum values is at 0.03-0.06×10
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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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