Table 3.
Estimates of the surface scavenging rate constants (k≡S) using Eq. (13) (S.1) for silica, alumina, and montmorillonite in Fe-AHP and UV-AHP treatment systems.
| [mineral] (g/L) | kRhB a (1/s) | [•OH]SS a (mol/L) | k≡S a (1/m2 × s) |
|---|---|---|---|
| Fe-AHP b | |||
| silica | |||
| 0 (n = 3) | 8.37 × 10−4 | 3.35 × 10−14 | – |
| 1 (n = 2) | 6.18 × 10−4 | 2.48 × 10−14 | 6.61 × 106 |
| 5 (n = 2) | 5.93 × 10−4 | 2.38 × 10−14 | 1.53 × 106 |
| 10 (n = 2) | 4.15 × 10−4 | 1.66 × 10−14 | 1.88 × 106 |
| 20 (n = 2) | 3.08 × 10−4 | 1.24 × 10−14 | 1.58 × 106 |
| 30 (n = 2) | 1.57 × 10−4 | 6.27 × 10−15 | 2.66 × 106 |
| Avg. 2.85 × 106 | |||
| alumina | |||
| 0 (n = 3) | 8.37 × 10−4 | 3.35 × 10−14 | – |
| 1 (n = 3) | 7.31 × 10−4 | 2.92 × 10−14 | 4.15 × 106 |
| 10 (n = 2) | 4.32 × 10−4 | 1.73 × 10−14 | 2.64 × 106 |
| 50 (n = 2) | 8.83 × 10−5 | 3.54 × 10−15 | 4.86 × 106 |
| Avg. 3.92 × 106 | |||
| UV-AHP c | |||
| silica | |||
| 0 (n = 3) | 4.09 × 10−4 | 1.64 × 10−14 | – |
| 1 (n = 1) | 3.28 × 10−4 | 1.31 × 10−14 | 4.50 × 106 |
| 10 (n = 1) | 1.19 × 10−4 | 4.74 × 10−15 | 4.50 × 106 |
| Avg. 4.50 × 106 | |||
| alumina | |||
| 0 (n = 3) | 4.09 × 10−4 | 1.64 × 10−14 | – |
| 1 (n = 3) | 2.99 × 10−4 | 1.20 × 10−14 | 1.10 × 107 |
| 5 (n = 2) | 1.55 × 10−4 | 6.20 × 10−15 | 9.17 × 106 |
| 10 (n = 3) | 1.18 × 10−4 | 4.73 × 10−15 | 7.02 × 106 |
| 50 (n = 3) | 6.17 × 10−5 | 2.47 × 10−15 | 3.21 × 106 |
| Avg. 7.45 × 106 | |||
| montmorillonite | |||
| 0 (n = 3) | 4.09 × 10−4 | 1.64 × 10−14 | – |
| 1 (n = 2) | 1.38 × 10−4 | 5.50 × 10−15 | ≤1.01 × 106 |
| 5 (n = 2) | 8.67 × 10−5 | 3.47 × 10−15 | ≤3.82 × 105 |
| 10 (n = 2) | 7.25 × 10−5 | 2.90 × 10−15 | ≤2.38 × 105 |
| 50 (n = 2) | 5.83 × 10−5 | 2.33 × 10−15 | ≤6.17 × 104 |
| Avg. ≤4.22 × 105 | |||
Average kRhB and [•OH]SS for mineral phase concentrations 0–50 g/L; kRhB in the Fe-AHP system 0.93 ≤r2 ≤ 0.99; kRhB in the UV-AHP system 0.94 ≤ r2 ≤ 0.99.
Fe-AHP system: Average k≡S (n = 10) using 1–30 g/L silica (95% C.I. = 1.29 × 106–4.42 × 106 1/m2 × s); average k≡S (n = 7) using 1–50 g/L alumina (95% C.I. = 2.44 × 106–5.41 × 106 1/m2 × s).
UV-AHP system: Average k≡S (n = 2) using 1–10 g/L silica (95% C.I. = 4.47 × 106–4.53 × 106 1/m2 × s; average k≡S (n = 11) using 1–50 g/L alumina (95% C.I. = 7.29 × 106–7.61 × 106 1/m2 × s); average k≡S (n = 8) using 1–50 g/L montmorillonite (≥1.02 × 105–7.42 × 105 1/m2 × s).