Table 9 Thermodynamics parameters of methylene blue and congo red adsorption by activated carbons.

From: Twigs-derived activated carbons via H3PO4/ZnCl2 composite activation for methylene blue and congo red dyes removal

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