Synthesis and kinetic adsorption characteristics of Zeolite/CeO2 nanocomposite

Abstract

Adsorption is an effective method for treating polluted water bodies. In this study, Zeolite/Cerium oxide nanocomposite (Z/CeO2NC) was hydrothermally synthesize and its adsorption capacity on methylene blue organic dye (MB) studied. The as-synthesized nanocomposite (Z/CeO2–NC) were characterized using X-Ray Diffraction (XRD), Fourier Transform Infra-Red (FT-IR), Energy Dispersive X-Ray Spectroscopy (EDX) and Scanning Electron Microscopy (SEM). Kinetic models and sorption isotherms were used to predict the adsorption rate constants and process mechanisms. The synthesized Z/CeO2NC showed an excellent adsorption kinetics of methylene blue and the characteristics of adsorption best fitted a pseudo-second-order model. The rate parameters of other models were evaluated and compared to establish the adsorption mechanisms. The Langmuir isotherm model best fitted the adsorption process indicating a homogeneous monolayer of the dye on the surface of the adsorbent. The thermodynamic Gibbs free energy (ΔG) parameter was determined to be negative, indicating a spontaneous adsorption process. The synthesized Z/CeO2NCs showed strong adsorption for methylene blue dye with increasing amount of CeO2. The maximum adsorption efficiency was calculated as 93.9% and the maximum regeneration efficiency of the adsorbent was found to be 78.8% higher after it had been washed by alkaline solution of pH 13. The results reflect the feasibility of the nanocomposite as an adsorbent with a potential application in wastewater treatment technologies. Keywords: Kaolin, SEM, Zeolite A, Cerium oxide adsorbent, Methylene blue, Kinetics