ZnFe2O4@SiO2@Tragacanth gum nanocomposite: synthesis and its application for the removal of methylene blue dye from aqueous solution

چکیده مقاله

In this study, the ZnFe2O4@SiO2@Tragacanth gum magnetic nanocomposite as a novel adsorbent was synthesized and was confirmed by FTIR, XRD, TEM, TGA and VSM methods. Then, the prepared nanocomposite has been tested for the removal of methylene blue dye from aqueous solution for adsorption process, and the effect of various parameters including pH (2–12), adsorbent dosage (0.2–2 g/L), temperature (15–45 °C), initial dye concentration (10–60 mg/L) and contact time (5–120 min), also its isotherms and kinetics has been studied. The results showed that the optimum pH, contact time, initial dye concentration, adsorbent dosage and maximum adsorption capacity were 8, 60 min, 60 mg/L, 0.2 g/L and 109.37 mg/g, respectively. Furthermore, the experimental data determined that the adsorption of methylene blue dye interpreted the Freundlich isotherm (R2 = 0.979) and the pseudo-second-order kinetics model (R2 = 0.998). Also, the thermodynamic parameters of the absorption system, such as changes in enthalpy (ΔH = + 9.36 kJ/mol), entropy (ΔS = + 40.72 J/mol k) and Gibbs free energy (ΔG = − 3.5 kJ/mol), were measured and showed that adsorption process of ZnFe2O4@SiO2@Tragacanth gum magnetic nanocomposite was endothermic and spontaneous process. As a result, due to high adsorption capacity, environment friendly, low cost, rapid extraction and non-toxicity, the ZnFe2O4@SiO2@TG magnetic nanocomposite can be used as an effective adsorbent for methylene blue removal from aqueous solutions.