Table 7 Pseudo-first-order and pseudo-second-order kinetics constants.

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

Activated carbon

Co (mg/L)

Qe,exp (mg/g)

Pseudo-first-order

Pseudo-second-order

Qe (mg/g)

k1 (min−1)

SSE

R2

Qe (mg/g)

k2 (g/mg min)

SSE

R2

Methylene blue

TAC2

20

19.9

19.4

0.434

33.1

0.9193

19.9

0.039

13.1

0.9680

100

95.6

90.0

0.147

1,339

0.8639

93.3

0.003

431

0.9555

TAC3

20

19.8

18.8

0.405

53.3

0.8693

19.4

0.032

23.7

0.9418

100

89.9

81.6

0.189

1607

0.8052

85.1

0.003

718

0.9128

TAC4

20

15.6

14.1

0.209

29.2

0.8903

14.6

0.022

11.7

0.9558

TAC5

20

18.4

16.9

0.088

68.7

0.8695

17.66

0.009

21.1

0.9557

TAC6

20

19.8

18.2

0.150

65.2

0.8676

18.9

0.013

18.5

0.9614

Congo red

TAC2

20

17.0

15.7

0.009

38.5

0.9528

17.7

0.0007

17.2

0.9728

TAC3

20

17.8

15.3

0.019

89.9

0.8460

16.9

0.0015

47.3

0.9070

TAC4

20

14.9

14.2

0.006

15.2

0.9808

16.5

0.0004

6.86

0.9887

TAC5

20

19.6

17.3

0.027

88.0

0.8628

18.9

0.002

39.0

0.9335

100

76.1

66.9

0.048

1,024

0.8637

71.7

0.001

380

0.9461

TAC6

20

18.5

17.2

0.011

38.1

0.9613

19.3

0.0007

16.5

0.9787

100

66.8

59.5

0.016

705

0.9245

66.2

0.0003

276

0.9674