The activated carbons (ACPRs) derived from Polyethylene terephthalate (PET) residues was prepared using wet impregnation of potassium hydroxide. The influence of the impregnation ratio on textural properties were evaluated. The overall porosity was improved with increasing impregnation ratio. For applying adsorption-based wastewater treatment system, the chitosan granules (CB-ACPR) combined with the ACPRs were prepared. In order to estimate the methylene blue (MB) adsorption capability of the CB-ACPR, the adsorption equilibrium isotherm and kinetic studies were evaluated. The adsorption equilibrium isotherm of MB on the CB-ACPR was represented by Sips isotherm model. The pore diffusion model was employed to determine the internal diffusion coefficient and the results was in good agreement with experimental kinetic data. Adsorption equilibrium capacities and diffusion coefficients of the MB increased with initial concentration.