Table 2. Comparison of Adsorption Capacity for Mercury(II) Ions.
| adsorbents | BET (m2/g) | pH | fitting model | Qm (mg/g) | ref |
|---|---|---|---|---|---|
| lignocellulosic | 5 | Freundlich | 20 | (4) | |
| SBA-15-SH | 50.9 | 8 | Freundlich | 195.6 | (14) |
| PEI-AC | 5 | Langmuir | 16.4 | (38) | |
| carbon nanotube | 8 | Langmuir | 100 | (39) | |
| magnetic polypyrrole–GO | 1737.6 | 7 | Langmuir | 400 | (20) |
| thiol-functionalized Fe3O4 | 6 | Langmuir | 344.8 | (40) | |
| thiol-functionalized aluminum oxide hydroxide nanowhiskers | 7 | Langmuir | 114 | (41) | |
| coal-based activated carbon | 900 | 4 | Langmuir | 48.0 | (42) |
| NiFe2O4-PAC-SH | 1241.2 | 7 | Langmuir | 366.3 | this work |