Table 8. Comparison between the Synthesized MNPs-SiO2-SB-THCA and MNPs-SiO2-SB-THCTA and the Previously Published Sorbents for the Removal of Cr(VI) Ions.
| adsorbents | adsorption conditions |
isotherm model | Qmax (mg/g) | refs | ||||
|---|---|---|---|---|---|---|---|---|
| initial C0 (mg/L) | pH | temp. (K) | contact time (h) | sorbent dosage | ||||
| biochar and activated carbon | 100 | 2 | 298 | 12 | 2.0 g/L | Langmuir | 45.3 | (49) |
| nitrogen-doped carboxylated porous carbon | 200 | 3 | 298 | 1.5 | 1.0 g/L | Langmuir | 104 | (50) |
| 3-MPA-coated SPION | 10 | 1 | 298 | 1 | 0.5 g/mL | Langmuir, Freundlich | 45 | (51) |
| APTES@TEOS@MNP | 100 | 2.5 | 298 | 1 | 0.02 g/L | Langmuir | 35 | (52) |
| nitrogen doping hydrothermal carbon material | 50 | 2 | 298 | 1 | 1.0 g/L | Langmuir | 99 | (53) |
| MNPs@SiO2-SB-THCTA | 50 | 6 | 298 | 1 | 0.01 g/L | Freundlich | 15.5 | current study |
| MNPs@SiO2-SB-THCA | 50 | 6 | 298 | 1 | 0.01 g/L | Freundlich | 14.3 | |