Abstract

Raphanus sativus press cake, a solid residue from biodiesel production, was evaluated as precursor material for the production of adsorbents. A comparative evaluation of acid and basic activating agents is presented, as well as conventional and microwave carbonization. The treatment that provided best adsorption performance was microwave activation employing KOH. Characterization results pointed to a homogeneous and porous adsorbent surface, and results from both kinetics and equilibrium essays indicated that methylene blue adsorption was probably taking place at the surface. Adsorption kinetics and equilibrium were satisfactorily described by the pseudo second-order and Langmuir models, respectively. Adsorption tests showed that the prepared adsorbents presented higher adsorption capacity than activated carbons produced from other agricultural residues, confirming that this type of waste material is a suitable candidate for use in the production of adsorbents.