مشخصات پژوهش

In this study multiwall carbon nanotubes (MWCNTs) was decorated on calcined eggshell(CES) to obtain a novel and low cost nano-sorbent for removal purposes. The MWCNTs/CESwas prepared by a simple hydrothermal method and was characterized by X-ray pow-der diffraction, scanning electron microscopy and zeta potential measurements. Removalefficiency of the nano-sorbent was evaluated using anionic Congo red dye as a samplepollutant. The experiments were carried out in a batch system to optimize operation vari-ables such as adsorbent dosage, Congo red concentration, solution pH and contact time.Langmuir, Freundlich, Tempkin and Dubinin–Raduskovich adsorption isotherm modelswere studied and the experimental results were addressed by Langmuir isotherm model.The maximum adsorption capacity was 136.99 mg g−1, indicating high potential of MWC-NTs/CES in the adsorption of Congo red. The adsorption kinetics was studied with thepseudo-first-order, pseudo-second-order, Elovich and intraparticle diffusion models. Thethermodynamic parameters indicated that the adsorption of Congo red on the MWCNTs/CESwas an exothermic and spontaneous process. Based on experimental results, MWCNTs/CESexhibit improved adsorption performance in comparison with non-treated eggshell (NES)and CES.