Table 2 The data from the first-order kinetic models of δ-MnO2 and acid birnessite with varying temperature, pH, and As(III) concentration
From: The influence of environmental conditions on kinetics of arsenite oxidation by manganese-oxides
Experimental conditions | Time scale (min) | kobserved (s−1) | r2 |
|---|---|---|---|
δ-MnO2 | |||
10 °C | 5–90 | 0.0026 | 0.8574 |
25 °C | 5–90 | 0.0027 | 0.9409 |
40 °C | 5–90 | 0.0037 | 0.9414 |
100 μM As(III) | 0–5 | 1.3684 | 1.0000 |
1 mM As(III) | 5–90 | 0.00234 | 0.9271 |
10 mM As(III) | 5–60 | 0.0011 | 0.8422 |
Acid birnessite | |||
pH 4.2 | 0–15 | 0.4326 | 0.9342 |
pH 7.2 | 0–15 | 0.1326 | 0.9829 |
pH 9.0 | 0–30 | 0.2456 | 0.9196 |
10 °C | 0–90 | 0.0043 | 0.8972 |
25 °C | 0–30 | 0.0131 | 0.8688 |
40 °C | 0–10 | 0.0441 | 0.8532 |
100 μM As(III) | 0–15 | 0.1326 | 0.9829 |
1 mM As(III) | 0–30 | 0.0131 | 0.8688 |
10 mM As(III) | 0–30 | 0.0143 | 0.8507 |