Table 3.

Description of non-linear kinetic models.

Kinetic Models	Non-linear Equations
Pseudo First Order Kinetics (PFO)	$qt=qe(1-(\mathit{exp}-k_{1}t)$
Pseudo Second Order Kinetics (PSO)	$qt=\frac{q{K}_{2}t}{{1+q}_e{k}_{2}t}$
Elovich Model	$q_t=\frac{1}{\beta }\mathit{ln}\left(1+\alpha \beta t\right)$

Where qe (mg/g) is adsorption capacity at equilibrium; qt (mg/g), adsorption capacity or concentration of solute in a solid phase at time t (min); K₁ (min⁻¹), pseudo-first-order rate constant; K₂ (g/mg min), pseudo-second-order rate constant.