Agriculture Reference
In-Depth Information
0.28
Olivier
0.24
Webster
0.20
Windsor
0.16
Initial Cd = 0.025 mM
0.12
0.0
0.2
0.4
0.6
0.8
8
7
Webster
6
5
Olivier
4
Windsor
3
Initial Cd = 0.766 mM
2
0.0
0.2
0.4
0.6
0.8
Initial Ni Concentration (mM )
FIGURE 7.15
Competitive sorption of Cd in the presence of Ni for Windsor, Olivier, and Webster soils. Initial
Cd concentrations were 0.025 mM (top) and 0.766 mM (bottom).
top) and 0.766 mM
(Figure 7.14, bottom). These results indicate that Ni sorp-
tion decreased as the competing Cd concentration increased. In Figure 7.15,
results are shown for Cd sorption in the presence of a range of Ni con-
centrations for all three soils. Here Cd adsorption decreased with increas-
ing Ni concentrations. Moreover, the extent of the decrease in Ni or Cd
sorption in this competitive systems was dissimilar among the three soils.
For the two acidic soils (Windsor and Olivier), Ni adsorption decreased
substantially with increasing Cd concentration in comparison to Webster,
the neutral soil. This finding was consistent for both initial Ni concentra-
tions (0.025 and 0.766 mM—see Figure 7.14). The amount of Ni sorbed in the
presence of 0.766 mM
Cd was reduced by 0.5%, 18%, and 45% for Webster,
Olivier, and Windsor soil, respectively. When 0.766 mM
Ni was present,
sorbed Cd was reduced by 20%, 7.6%, and 15% for Windsor, Olivier, and
Webster soil, respectively.
Search WWH ::
Custom Search