Mineral: |
Ferrihydrite |
Reference: |
CZR91 |
SCM Type: |
TL - Triple Layer |
Ligand: |
Ca<2+>
- calcium
|
Site Type: |
»Fe-OH |
Equation: |
»Fe-OH + Ca<2+> ⇔ »Fe-O-Ca<1+> + H<1+> |
LogK: |
-4.87 ± 0.22
LogK2.31 nm−2 (SSD-normalized): -3.93
|
Experiment: |
Batch Sorption Experiments |
Ionic Strength: |
NaNO3
|
Temperature: |
298.15 K |
pH Range: |
4.5-10.5 |
Ligand Concentration Range: |
1E-4 mol/L |
Fit Method: |
FITEQL |
Comment: |
data were modeled assuming the formation of only outer-sphere complexes (=FeO-Ca<+> and =FeO-CaOH); log K depends on initial Ca sorption and ionic strength! -> reflects the heterogeneity of the surface?; given value for 1E-4M Ca and I = 0.5, 0.1 and 0.005 M; fit not so good as with complexes =FeO-CaOH and (=FeO)2-Ca; Fe 0.77-0.87mM = 0.13-0.15 g/L Fe2O3*H2O |
|