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Table 3 Various isotherm parameters for nutrient adsorption onto biochar pellets in the single and mixed solute solutions

From: Chitosan impregnation of coconut husk biochar pellets improves their nutrient removal from eutrophic surface water

Model

Langmuir

Freundlich

Sips

Dubinin-Radushkevich

BET

Parameter

KL (L mg−1)

qmax (mg g−1)

R2

KF (mg1–1/nf L1/nf g− 1)

1/nf

R2

qmax (mg g− 1)

Ks (Lns mg-ns)

ns

R2

qmax (mg g− 1)

Β (mol2 J− 2)

E (kJ mol− 1)

R2

qBET (mg g− 1)

K1 (L mg− 1)

K2 (L mg− 1)

R2

NH4+

Single

CH

0.024

4.27

0.986

2.1 × 10− 1

0.63

0.984

5.28

2.3 × 10− 2

0.91

0.987

11.89

7.35 × 10−9

8.3

0.986

2.00

6.5 × 10− 2

6.0 × 10−3

0.984

CHC

0.006

3.59

0.923

3.4 × 10− 2

0.82

0.909

5.02

6.0 × 10− 3

0.92

0.924

4.87

8.30 × 10− 9

7.9

0.907

0.65

5.1 × 10− 2

7.0 × 10− 3

0.934

CHEG

0.102

1.38

0.604

5.1 × 10− 1

0.21

0.882

5.66

9.9 × 10−2

0.24

0.873

1.70

1.90 × 10−9

16

0.873

0.74

6.9

8.0 × 10−3

0.973

Mixed

CH

0.076

2.88

0.891

5.2 × 10−1

0.38

0.952

5.03

9.9 × 10− 2

0.54

0.943

5.86

4.29 × 10−9

11

0.940

1.21

9.1 × 10− 1

1.0 × 10− 2

0.931

CHC

0.009

3.41

0.905

1.9 × 10−2

1.04

0.929

4.67

3.0 × 10−3

1.21

0.934

18.25

1.26 × 10−8

6.2

0.935

0.39

1.3 × 10−1

1.3 × 10− 2

0.980

CHEG

0.034

3.43

0.969

2.8 × 10−1

0.52

0.964

5.89

3.2 × 10−2

0.74

0.970

8.82

6.40 × 10−9

8.8

0.970

2.33

5.6 × 10−2

3.0 × 10−3

0.970

NO3−

Single

CH

0.005

4.45

0.845

3.0 × 10−3

1.43

0.949

5.67

1.0 × 10−3

1.28

0.924

6.43

7.58 × 10−9

8.1

0.852

0.37

6.2 × 10−2

9.0 × 10− 3

0.983

CHC

0.044

1.60

0.907

1.8 × 10−1

0.45

0.917

1.52

3.9 × 10−2

1.07

0.928

3.71

3.83 × 10−9

11

0.929

0.97

1.3 × 10−1

4.0 × 10−3

0.938

CHEG

0.125

3.80

0.949

8.4 × 10−1

0.37

0.994

7.70

1.1 × 10−1

0.52

0.990

10.60

3.46 × 10−9

12

0.992

2.29

3.5 × 10−1

8.0 × 10−3

0.999

Mixed

CH

0.081

0.76

0.930

1.4 × 10−1

0.38

0.965

1.27

9.3 × 10−2

0.59

0.967

2.06

3.74 × 10−9

11

0.969

0.42

2.4 × 10−1

7.0 × 10−3

0.955

CHC

0.013

1.28

0.927

3.9 × 10−2

0.65

0.953

1.65

2.5 × 10−2

0.71

0.932

4.21

6.66 × 10−9

8.7

0.946

0.27

2.1 × 10− 1

9.0 × 10−3

0.987

CHEG

0.087

0.91

0.933

2.2 × 10−1

0.30

0.978

1.73

1.3 × 10− 1

0.45

0.988

1.87

2.92 × 10−6

0.4

0.988

0.58

5.1 × 10−1

4.0 × 10−3

0.973

PO43−

Single

CH

NA

NA

NA

5.1 × 10−4

1.96

0.892

5.08

1.6 × 10−6

3.06

0.940

2270.88

2.12 × 10−8

4.8

0.917

41.03

3.2 × 10−4

5.0 × 10−3

0.890

CHC

NA

NA

NA

2.0 × 10−3

1.51

0.896

2.90

5.8 × 10−5

2.32

0.952

299.11

1.60 × 10−8

5.6

0.924

35.80

3.6 × 10− 4

3.0 × 10− 3

0.895

CHEG

NA

NA

NA

1.4 × 10− 4

2.20

0.900

4.99

6.3 × 10−6

2.65

0.929

3503.18

2.32 × 10−8

4.6

0.923

37.28

1.9 × 10−4

6.0 × 10−3

0.824

Mixed

CH

0.001

14.83

0.846

1.1 × 10−2

1.08

0.815

1.89

6.9 × 10−7

3.53

0.940

59.28

1.19 × 10−8

6.5

0.871

3.12

5.0 × 10−3

2.0 × 10− 3

0.805

CHC

0.001

6.91

0.921

1.2 × 10−2

0.87

0.914

1.10

7.7 × 10−4

1.63

0.925

14.21

1.04 × 10−8

6.9

0.922

2.68

3.0 × 10−3

8.1 × 10− 4

0.921

CHEG

0.073

1.50

0.975

3.6 × 10−1

0.30

0.934

1.50

7.4 × 10−2

1.00

0.976

3.32

2.95 × 10−9

13

0.957

1.42

8.2 × 10−2

4.8 × 10−4

0.976

  1. NA means not applicable