Research Article
Metals Ions Removal by Polymer Membranes of Different Porosity
Table 2
Acidic properties of investigated adsorbents before and after filtration with 15 mg/dm3 copper solution (mmol/g).
| | Membrane | pKa | | | | | | <3 | 3–5 | 5–7 | 7–9 | 9–11 | >11 | Acidic groups | Total content of surface oxides | | A | B | A | B | A | B | A | B | A | B | A | B | A | B | A | B |
| | PES-18 PVP-1 | — | — | 3.86 | 2.11 | 1.32 | — | 0.14 | 0.08 | — | 1.02 | 1.72 | 0.50 | 7.04 | 3.71 | 8.98 | 6.97 | | PES-18 PVP-2 | — | — | 0.55 | 2.01 | — | — | 0.06 | 0.13 | 0.66 | 1.02 | 0.87 | 1.18 | 2.14 | 4.34 | 3.04 | 7.07 | | PES-18 PVP-3 | — | — | 0.58 | 1.85 | 0.98 | — | 0.21 | 0.11 | — | — | 1.54 | 2.01 | 3.31 | 3.97 | 5.19 | 5.65 | | PES-18 PVP-4 | — | — | 2.14 | 1.75 | — | — | 0.09 | 0.08 | 0.81 | 0.87 | 1.30 | 0.22 | 4.34 | 2.92 | 6.40 | 5.80 |
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A: before filtration, B: after filtration.
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