Aubert et al.(2004)による〔『Distribution and origin of major and trace elements (particularly REE, U and Th) into labile and residual phases in an acid soil profiles (Vosges Mountains, France)』（899p）から〕

『酸性土壌断面（フランスのVosges山脈）における不安定の残留相への主要および微量元素（とくにREE、U、およびTh）の分布と起源』

『Abstract
　A 7 step sequential extraction procedure has been conducted on a podzolic soil profile from the Vosges Mountains in order to determine the ability of several elements to be released to the environment. Very little Si, K and Al were extractable (＜10％ of the total soil concentration) but larger proportions (＞10％ of the total soil concentration) of Ca, P, metals (Fe, Pb), REE and actinides (Th, U) could be leached. For each element, preferential binding sites can be recognized. High recovery of P and Ca in the acid soluble fraction (AS) suggests that phosphate minerals are highly involved in this step of the extraction. Organic matter appears to control the adsorption of Ca, Fe, Th, U and REE, even at depths in the soil profile where organic matter content is particularly low (0.5％). Weak acid leaching experiments (with HCl and acetic acid 0.001 N) were also performed in order to characterize the origin of the insoluble material in this soil profile. The leachable REE distributions indicate that a large part of the labile REE in the surface horizon has an atmospheric origin whereas at greater depth phosphate mineral (apatite) alteration is the main factor controlling REE release in the leachate. The study further suggests that adsorbed material holding actinides and REE are not strictly the same. So, caution should be taken when using REE as analogues for actinides in soils systems.』

1. Introduction
2. Material and methods
　2.1. Site description
　2.2. Soil properties
　2.3. Sampling procedure
　2.4. Analytical methods
3. Results
　3.1. Mineralogical and chemical compositions of the soil samples
　3.2. Distribution of the elements on soil chemical phases: sequential extraction procedure
　　3.2.1. Slightly extracted elements (＜10％ of the original soil sample)
　　3.2.2. Strongly extracted elements (＞10％ of the original soil sample)
　3.3. Leaching experiments using dilute acetic acid and HCl
4. Discussion
　4.1. General comments
　4.2. Rare Earth Elements
　4.3. Analogy between Rare Earth Elements and actinides
5. Conclusions
Acknowledgements
References

戻る