Table 2.
Parameters of reductive dissolution kinetics
| Label | Wet solids | Dried solids | Ratio dried/wet | |||||
|---|---|---|---|---|---|---|---|---|
| ta50% (h) | tb1/2 (h) | kapp (h−1) | ta50% (h) | tb1/2 (h) | kcapp (h−1) | For t50% (−) | For t1/2 (−) | |
| Ca-00-00 | 5.4 | 5.4 | 0.13 | 7.4 | 7.5 | 0.092 | 1.36 | 1.39 |
| Ca-01-00 | 1.6 | 1.7 | 0.41 | 2.8 | 2.8 | 0.25 | 1.78 | 1.67 |
| Ca-02-00 | 1.5 | 1.5 | 0.47 | 2.3 | 2.5 | 0.28 | 1.55 | 1.70 |
| Ca-05-00 | 2.7 | 2.8 | 0.25 | 4.3 | 4.3 | 0.16 | 1.63 | 1.55 |
| Ca-15-00 | 6.9 | 6.9 | 0.10 | 7.6 | 7.8 | 0.089 | 1.11 | 1.12 |
| Na-15-00 | 7.5 | 7.7 | 0.090 | 7.8 | 8.3 | 0.084 | 1.04 | 1.07 |
| Ca-02-05 | 2.9 | 2.6 | 0.26 | 4.0 | 4.2 | 0.17 | 1.40 | 1.58 |
| Ca-02-10 | 6.2 | 6.2 | 0.11 | 8.0 | 7.9 | 0.088 | 1.12 | 1.22 |
| Ca-00-10 | 35 | 33 | 0.021 | 39 | 40 | 0.017 | 1.30 | 1.26 |
| 2L-Fh | 5.0 | 5.6 | 0.12 | 27 | − | − | 5.33 | − |
aTime required for the dissolution of 50% of the solids; derived from Figs. 1a, b, 2a, b, Additional file 1: Figures S3ab, and S4a by interpolating data points adjacent to 50% Fe reduction or set to time at which 50% Fe reduction was measured
bDissolution half-life time t1/2; calculated from kapp (t1/2 = ln(2)/kapp)
cApparent rate coefficient based on the assumption of pseudo-first-order dissolution kinetics; obtained by linear regression of linearized plots of ln(1 − c(t)/Fetot) versus t for data points up to 63% Fe dissolution (Figs. 1c, d, 2c, d and Additional file 1: Figure S3cd). The relative standard error for kapp ranged from 0.5 to 5.5%