2.7. Adsorption kinetics model

The adsorption rate, reaction mechanism and equilibrium time are fundamental in determining the effectiveness and efficiency of the adsorbent material as well as the mass transfer which explains the rate-limiting steps [40]. The pseudo-first-order, pseudo-second-order and intraparticle diffusion model were used to ascertain the best fitting for the experimental data.

Lagergren pseudo-first-order model

Pseudo-second-order model

Intraparticle diffusion model

where q_t and q_e are the amounts of MCPA adsorbed at certain equilibrium and time t (mg g⁻¹), K₁ (min⁻¹) is the pseudo-first-order rate constant, K₂ (g mg⁻¹ min⁻¹) is the equilibrium rate constant of the pseudo-second-order, and the intraparticle diffusion rate constant is represented as K_p (mg g⁻¹ min⁻¹).