Oxidizable fraction
Cesium is known to be relatively mobile in organic soils, particularly when organic matter content is in the order of several tens of percent (Staunton et al., 2002 and Wang et al., 2000). The relationship between the sorption of cesium and organic matter is complex, since the presence of a small amount of clay in soil is sufficient to make the sorption governed mainly by clay specific sites (Rigol et al., 2002). The results of extracted cesium for this fraction are shown in Table 3 and Fig. 3. They indicate, on the one hand, that about half of the cesium content in soils is retained only by the organic phase. On the other hand, the classification of soils according to the decreasing order of Cs extracted quantities (Table 3) (“Khachem” 1.752 ± 0.126 mg/g > “Hade” 1.411 ± 0.113 mg/g > “Birine” 1.288 ± 0.040 mg/g) is in agreement with their organic matter content (Table 2) (“Khachem” 2.14% > “Birine” 1.61% > “Hade” 1.56%) excepting the “Site” soil where the extract was 1.819 ± 0.200 mg/g while the OM value was 0.62%.