Table 3 Parameters of the Freundlich, Langmuir and Radke-Prausnitz isotherms for the fluoride adsorption on BC and BCMs from aqueous solution at different pH and temperature
Material | pH | T (°C) | Freundlich | Langmuir | Radke-Prausnitz | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
k (L1/n mg1−1/n g−1) | n | %D | K (L mg−1) | qm (mg g−1) | %D | a (L g−1) | b (L1−\({}^{{\upbeta}_{\text{RP}}}\) mg \({}^{{\upbeta}_{\text{RP}}}\)−1) | βRP | %D | |||
BC | 7 | 25 | 1.27 | 2.42 | 11 | 0.46 | 4.07 | 2.6 | 1.52 | 0.24 | -0.17 | 3.0 |
BCM1 | 3.28 | 3.56 | 16 | 1.37 | 7.07 | 9.2 | 9.58 | 1.35 | 0.00 | 9.2 | ||
BCM3 | 2.58 | 2.59 | 17 | 0.40 | 8.36 | 12 | 7.81 | 1.91 | 0.76 | 12 | ||
BCM4 | 0.75 | 2.27 | 12 | 0.10 | 4.36 | 28 | 2.88 | 3.12 | 0.39 | 12 | ||
BCM2 | 5 | 25 | 4.39 | 2.18 | 13 | 0.49 | 14.4 | 7.6 | 9.45 | 0.97 | 0.16 | 4.4 |
7 | 15 | 2.98 | 3.00 | 10 | 0.63 | 7.94 | 23 | 13.8 | 3.17 | 0.20 | 13 | |
25 | 4.17 | 2.90 | 27 | 0.95 | 10.2 | 17 | 8.91 | 0.75 | -0.06 | 21 | ||
35 | 4.81 | 2.99 | 16 | 1.14 | 11.2 | 9.7 | 16.7 | 1.87 | 0.09 | 4.8 | ||
9 | 25 | 0.73 | 2.21 | 14 | 0.13 | 4.05 | 7.8 | 0.61 | 0.21 | 0.09 | 9.5 | |