Treatment given | Cd | Pb | Fe | Cu | Ni | Cr6+ | Reference |
None |
| 65 |
| 48 |
|
| [47] |
None |
|
|
|
|
| 43a | [48] |
Na2S |
| 81 |
|
|
|
| [49] |
None |
|
|
|
| 10a |
| [50] |
None |
|
|
|
|
| 55b | [51] |
None |
|
|
|
| 18b |
| [52] |
None | 11 |
|
| 9 |
|
| [53] |
Acid washed |
| 79 |
| 27 |
|
| [54] |
None | 14 | 26 | 12 |
|
|
| This work |