TABLE 1.
Equilibrium metal speciation in M2M and NMS media at different total copper concentrationsa
| Medium | Metal speciation | Result obtained with total copper (μM)
|
||||
|---|---|---|---|---|---|---|
| 0.02 | 0.11 | 5 | 10 | 20 | ||
| M2M | Chelated Cu (%) | 100 | 100 | 99 | 96 | 94 |
| Precipitated Cu (%) | 0 | 0 | 0.5 | 3.6 | 5.6 | |
| Free Cu (%) | 0.089 | 0.048 | 0.013 | 0.014 | 0.015 | |
| pCub | 10.7 | 10.3 | 9.2 | 8.8 | 8.5 | |
| Soluble Fe (%) | 16 | 9 | 14 | 11 | 11 | |
| Precipitated Fe (%) | 84 | 91 | 86 | 89 | 89 | |
| NMS | Chelated Cu (%) | 100 | 94 | 93 | 70 | 59 |
| Precipitated Cu (%) | 0 | 5.9 | 7.2 | 30 | 38 | |
| Free Cu (%) | 0.16 | 0.14 | 0.08 | 0.21 | 2.8 | |
| pCu | 10.3 | 9.8 | 8.4 | 7.7 | 6.3 | |
| Soluble Fe (%) | 99 | 99 | 68 | 28 | 0 | |
| Precipitated Fe (%) | 1 | 1 | 32 | 62 | 100 | |
a
M2M and NMS have total iron concentrations of 0.9 and 9 μM, respectively.
b
Free copper concentrations at equilibrium, reported as the negative log of [Cu2+].