Table 9 Thermodynamics parameters of methylene blue and congo red adsorption by activated carbons.
Activated carbon | Co (mg/L) | T (K) | Kd | ln Kd | ΔG° (kJ/mol) | ΔH° (kJ/mol) | ΔS° (J/mol K) |
---|---|---|---|---|---|---|---|
Methylene blue | |||||||
TAC2 | 20 | 303 | 129.9 | 4.87 | – 12.3 | 88.2 | 333.4 |
313 | 699.0 | 6.55 | – 17.0 | ||||
323 | 1542 | 7.34 | – 19.7 | ||||
333 | 3,257 | 8.09 | – 22.4 | ||||
100 | 303 | 9.02 | 2.20 | – 5.54 | 68.7 | 245.2 | |
313 | 20.2 | 3.01 | – 7.82 | ||||
323 | 62.9 | 4.14 | – 11.1 | ||||
333 | 94.1 | 4.54 | – 12.6 | ||||
TAC3 | 20 | 303 | 13.7 | 2.62 | – 6.60 | 27.3 | 112.3 |
313 | 18.7 | 2.93 | – 7.62 | ||||
323 | 38.6 | 3.65 | – 9.81 | ||||
333 | 31.6 | 3.45 | – 9.56 | ||||
100 | 303 | 10.2 | 2.33 | – 5.86 | 39.6 | 150.3 | |
313 | 21.0 | 3.05 | – 7.93 | ||||
323 | 23.2 | 3.14 | – 8.44 | ||||
333 | 47.9 | 3.87 | – 10.7 | ||||
Congo red | |||||||
TAC5 | 20 | 303 | 5.55 | 1.71 | – 4.32 | 51.2 | 182.8 |
313 | 10.3 | 2.34 | – 6.08 | ||||
323 | 16.4 | 2.80 | – 7.51 | ||||
333 | 36.5 | 3.60 | – 9.96 | ||||
100 | 303 | 2.46 | 0.90 | – 2.27 | 17.7 | 66.3 | |
313 | 3.50 | 1.25 | – 3.26 | ||||
323 | 3.59 | 1.28 | – 3.43 | ||||
333 | 4.94 | 1.60 | – 4.42 | ||||
TAC6 | 20 | 303 | 6.94 | 1.94 | – 4.88 | 138 | 470 |
313 | 20.2 | 3.01 | – 7.82 | ||||
323 | 231 | 5.44 | – 14.6 | ||||
333 | 749 | 6.62 | – 18.3 | ||||
100 | 303 | 1.64 | 0.50 | – 1.25 | 18.9 | 66.9 | |
313 | 2.38 | 0.87 | – 2.25 | ||||
323 | 2.77 | 1.02 | – 2.74 | ||||
333 | 3.29 | 1.19 | – 3.30 |