Table 2.
Sorption isotherm models and best-fit parameters for Sb(V) sorption data.
| Biochar | qexp (mg/g) | Langmuir model parameters | Freundlich model parameters | Temkin model parameters | Dubinin–Radushkevich model parameters | pH | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| qcal (mg/g) | qm (mg/g) | KL (L mg−1) | RL | R2 | qcal (mg/g) | KF (g mg−1 h−1) | 1/n | R2 | b (J/mol) | A (L/g) | R2 | qm (mg/g) | E (kJ mol−1) | β | R2 | |||
| BSBC | 12.71 | 12.07 | 17.54 | 0.041 | 0.18–0.69 | 0.95 | 12.90 | 1.27 | 0.584 | 0.99 | 731.6 | 0.56 | 0.93 | 80.23 | 9.80 | 5.2 × 10−3 | 0.99 | 2 |
| ZrBSBC6.5 | 35.31 | 34.10 | 46.95 | 0.039 | 0.11–0.71 | 0.98 | 39.92 | 2.719 | 0.636 | 0.99 | 261 | 0.46 | 0.96 | 253.26 | 9.36 | 5.7 × 10−3 | 0.99 | 2 |
| ZrBSBC12.5 | 51.68 | 49.45 | 66.67 | 0.123 | 0.03–0.44 | 0.97 | 57.83 | 8.039 | 0.627 | 0.98 | 177.45 | 1.23 | 0.98 | 508.96 | 9.90 | 5.1 × 10−3 | 0.99 | 2 |
| Zr–FeBSBC (1:20) | 47.12 | 41.60 | − 31.8 | − 0.033 | 1.52–0.16 | 0.54 | 33.89 | 0.910 | 1.271 | 0.92 | 153.94 | 0.39 | 0.63 | 4395 | 6.93 | 1.0 × 10−2 | 0.90 | 2 |
| 48.81 | 47.07 | − 60.61 | − 0.037 | 4.0–0.14 | 0.67 | 42.58 | 1.986 | 1.248 | 0.97 | 116.26 | 0.49 | 0.81 | 3202 | 7.58 | 8.7 × 10−3 | 0.96 | 3 | |
| 48.04 | 48.84 | 98.04 | 0.055 | 0.077–0.63 | 0.96 | 56.56 | 5.41 | 0.8128 | 0.98 | 162.64 | 1.01 | 0.96 | 1120 | 9.77 | 6.5 × 10−3 | 0.99 | 4 | |
| Zr–FeCl3BSBC (1:5) | 38.80 | 36.40 | 70.42 | 0.011 | 0.89–0.29 | 0.96 | 31.43 | 1.633 | 0.796 | 0.99 | 251.55 | 0.42 | 0.89 | 456 | 8.45 | 7.0 × 10−3 | 0.99 | 2 |
| 44.16 | 37.64 | 125 | 0.014 | 0.87–0.25 | 0.49 | 39.20 | 1.929 | 0.883 | 0.99 | 173.58 | 0.37 | 0.86 | 644 | 8.45 | 7.0 × 10−3 | 0.98 | 3 | |
| 44.49 | 44.47 | 85.47 | 0.029 | 0.13–0.76 | 0.97 | 50.08 | 3.12 | 0.772 | 0.99 | 185.73 | 0.54 | 0.93 | 727 | 9.57 | 6.8 × 10−3 | 0.99 | 4 | |
| 47.36 | 35.44 | 112.36 | 0.017 | 0.85–0.21 | 0.20 | 35.81 | 2.139 | 0.857 | 0.94 | 229.9 | 0.51 | 0.82 | 274 | 9.62 | 5.4 × 10−3 | 0.93 | 5 | |
| FeBSBC | 39.80 | 32.91 | 120.48 | 0.006 | 0.93–0.41 | 0.35 | 32.16 | 1.13 | 0.833 | 0.99 | 260.03 | 0.32 | 0.76 | 325 | 8.45 | 7.0 × 10−3 | 0.98 | 2 |
| 28.98 | 26.51 | 39.68 | 0.02 | 0.18–0.83 | 0.95 | 30.29 | 1.36 | 0.6739 | 0.99 | 365.14 | 0.35 | 0.91 | 181 | 8.98 | 6.2 × 10−3 | 0.99 | 3 | |
| 41.26 | 36.53 | 49.26 | 0.071 | 0.006–0.57 | 0.91 | 43.39 | 4.684 | 0.603 | 0.88 | 238.79 | 0.86 | 0.93 | 444 | 9.21 | 5.9 × 10−3 | 0.93 | 4 | |
| FeCl3BSBC | 41.76 | 34.67 | 270.27 | 0.003 | 0.96–0.57 | 0.21 | 35.16 | 1.0139 | 0.9447 | 0.99 | 216.26 | 0.31 | 0.80 | 799 | 7.71 | 8.4 × 10−3 | 0.99 | 2 |
| 24.60 | 22.66 | 31.54 | 0.022 | 0.17–0.81 | 0.95 | 26.08 | 1.313 | 0.6279 | 0.98 | 432.41 | 0.34 | 0.92 | 135 | 9.20 | 5.9 × 10−3 | 0.99 | 3 | |