Langmuir model

Freundlich model

adsorbent

adsorbate

q_m (mmol∙g⁻¹)

K_L (L∙mmol⁻¹)

R²

n

K_F (mmol∙L^−1/n∙L^1/n∙g⁻¹)

R²

Sewage sludge

Cd²⁺

0.25

1.17

0.986

3.25

0.35

0.962

Pb²⁺

0.35

3.50

0.982

0.44

2.68

0.936

Ni²⁺

0.20

0.52

0.991

0.21

2.15

0.984

Alkali treated sludge

Cd²⁺

0.76

21.14

0.993

0.80

3.50

0.947

Pb²⁺

1.05

35.09

0.970

1.07

4.69

0.929

Ni²⁺

0.52

3.18

0.992

0.55

2.04

0.990