Name

Form

Meaning of Parameter

Applicability

Reference

Langmuir

$q_e=\frac{q_m{C}_e}{K_L+C_e}$

q_e: the adsorption capacity at adsorption equilibrium (mg/g - resin)

q_m: the theoretical maximum adsorption capacity (mg/g-resin)

K_L: the Langmuir constant

C_e: the equilibrium concentration in liquid phase

Monolayer adsorption on uniform surface

[18]

Freundlich

$q_e=K_F{C}_e^{1/n}$

K_F: the Freundlich constant

1/n: an empirical constant

Monolayer adsorption on a heterogeneous surface

[39]

Henry

$q_e=K_H{C}_e$

K_H: the Henry constant

The amount of adsorption accounts for less than 10% of the amount of adsorption forming the monolayer

[68]

Redlich–Peterson

$q_e=\frac{K_R{C}_e}{1+a_R{C}_e^g}$

K_R: the Redlich-Peterson constant

a_R: an empirical constant

g: an empirical constant that is between 0 and 1

Monolayer adsorption

[69]