ISSN:
1573-2932
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Energietechnik
Notizen:
Abstract The association of Cd with different soil components and the rate of exchange between 109Cd and stable Cd in the soils were studied by using a sequential extraction technique. The experiments were performed after different contact times between 109Cd and the soils (5 min-221 days). According to the short term batch experiments, based on a loam soil (ås, Eastern-Norway), no significant differences in the distribution of 109Cd were observed after a contact time of about 1 hour. On average, the relative distribution of 109Cd among exchangeable, easily reducible, oxidizable and acid-digestable fractions was about 25, 60, 10, and 2%, respectively. In the pot experiment, a loam soil (ås) and a loamy sand (Birkenes, Southern-Norway) were adjusted to pH 5.5 and 6.5 and spiked with 109Cd before storing them in pots at room temperature and at about 15% moisture content. 109Cd was rapidly distributed, and the two soils showed only minor differences with respect to the distribution of 109Cd among soil fractions with time (2–221 days). The amounts of 109Cd in the more easily available fractions; NH4-acetate fraction (F1) and NH2OH · HCl fraction (F2), however, were higher in the soil from Birkenes (pH 5.0) which was originally more acidic than the soil from As (pH 6.1). The 109Cd/stable Cd ratio, calculated from the relative distribution of radioactive and stable Cd in the different fractions, did not vary significantly from 2 days to 221 days, but the ratios were higher in the more easily available fractions; i.e. NH4-acetate fraction (F1) and NH2OH · HCl fraction (F2). The fixation of Cd in soils appears to be a slow process as the relative distribution (%) of 109Cd/ stable Cd in the strongly bound fraction; extracted with 7 M HNO3 at 80
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00477993
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