Iodine-129 and Caesium-137 in Chernobyl contaminated soil and their chemical fractionation

Biogeochemical Considerations Related To The Remediation Of I-129 Plumes

“…In the coastal and estuarine area of Sellafield, most of the 129 I was associated with the oxides (53 to 66%) and organic (23-43%) fractions, whereas <7.5% was found in the other fractions. A similar result was also obtained from soil samples collected from near the Chernobyl accident: 30 to 40% of the 129 I was associated with the oxides, 40 to 48% with the organics, and only 6 to 13% with the water soluble fraction (Hou et al, 2003). …”

“…This technique involves adding extractants designed to remove iodine associated with a given phase (e.g., water soluble, carbonate, Fe-(oxy)hydroxide, organic matter, residual) or sorbed by a specific process (e.g., exchangeable). Sequential extractions have been carried out to investigate iodine speciation in sediments (Hou et al, 2003;Schmitz and Aumann, 1995;Stutz et al, 1999;Yuita, 1992). These are operationally defined parameters and as such do not carry mechanistic interpretations.…”

A review on speciation of iodine-129 in the environmental and biological samples

“…Empirical data have shown different ratios of 129 I/ 127 I for the different chemical species in water, soil, sediment [20][21][22][23], implying that the speciation of anthropogenic 129 I in the environment is different compared to the speciation of stable iodine. The concentration of 129 I in the environmental samples is normally 4-12 orders of magnitude lower than that of stable iodine, for this reason the analytical methods, including the species separation and analytical techniques for the stable iodine ( 127 I) can not be directly used for 129 I.…”

Natural iodine in a clay formation: Implications for iodine fate in geological disposals

“…This latter is inspired by Tessier (1979). Even if this protocol was developed for cation, Hou et al (2003) have shown that it is possible to apply it to iodine* chemical fractionation in…”

“…This could be linked to sample heterogeneity but also to the sequential extraction procedure itself. Indeed, some authors have suggested that the H 2 O 2 -HNO 3 mixture step used in the Tessier procedure can lead to loss of iodine* in the leaching process (Hou et al, 2003). This could also explain the lesser extent of iodine* recovery with HNO 3 digestion than with RNAA.…”