and also followed the intraparticle diffusion model up to 60 min, whereas diffusion is not only the rate controlling step. The Langmuir, Freundlich
and Dubinin–Radushkevich (D–R) adsorption models were applied to describe the equilibrium isotherms and the isotherm constants were also determined. The Langmuir, Freundlich and D–R models agree with experimental data well.