| pH (medium) | Adsorption, % | ||||
| Zn(II) | Pb(II) | Cd(II) | Cu(II) | Co(II) | |
| 1.0 (hyrochloric acid) | 30 | 0 | 0 | 0 | 0 |
| 1.7 (oxalate buffer) | 69 | 0 | 0 | 50 | 39 |
| 4.0 (phthalate buffer) | 84 | 18 | 10 | 10 | 0 |
| 6.9 (phosphate buffer) | 99 | - | 50 | 70 | 30 |
| (distilled water) | 100 | 93 | 97 | 100 | 95 |
| 8.0 (ammonium-acetate buffer) | 100 | 86 | 75 | 99 | 66 |