First-order kinetic model

Second-order kinetic model

Intraparticle diffusion

metal ion

q_exp

(mg∙g⁻¹)

k₁

(min⁻¹)

q₁

(mg∙g⁻¹)

R²

k₂

(g∙mg⁻¹∙min⁻¹)

q₂

(mg∙g⁻¹)

R²

k_p

(mg∙g⁻¹∙min^−1/2)

R²

Cd(II)

8.11

4.80 × 10⁻²

9.25

0.754

1.45 × 10⁻²

8.53

0.994

3.8885

0.966

Pb(II)

21.21

6.03 × 10⁻²

15.85

0.967

4.30 × 10⁻³

24.10

0.998

0.8385

0.965

Fe(II)

6.71

5.44 × 10⁻²

2.51

0.975

1.75 × 10⁻¹

3.53

0.996

4.0569

0.976