Mineral: |
amorphous Silica |
Reference: |
SVV03 |
SCM Type: |
CC - Constant Capacitance |
Ligand: |
UO2<2+>
- uranyl(VI)
|
Site Type: |
»Si-OH |
Equation: |
»SiOH + 2 UO2<2+> + 2 OH<1-> ⇔ »SiO-(UO2)2(OH)2<1+> + H<1+> |
LogK: |
9.14 LogK°I=0 (Conversion to I = 0): 9.54
|
Experiment: |
Batch Sorption Experiments |
Ionic Strength: |
0.01 mol/L
NaNO3
|
Temperature: |
301.0 K |
Solid/Liquid Ratio: |
5.0 g/L |
pH Range: |
2-9 |
Ligand Concentration Range: |
8.4E-5 mol/L |
Fit Method: |
Comment: |
fit by Newton-Raphson's multidimensional non-linear regression method, using a computer code developed by Stamberg et al.; sigma of K=2.62E4 based on reaction XO- + (UO2)2(OH)22+ = XO(UO2)2(OH)2+; value of logK eliminated from modeling; logK = -13.22 for the reaction »Si-OH + (UO2)2(OH)2<2+> = »Si-O-(UO2)2(OH)2<+> + H<1+>; formation constant in aqueous solution: 2UO2<2+> + 2OH<1-> = (UO2)2(OH)2<2+> with logK = 22.36 |
|