Synthesis of Kit-6 Magnetite Silica Nanocomposite Functionalized by Amine Group for Removal of Carmoisine Dye from Aqueous Solutions

Objective: In this study, amine-functionalized magnetite Kit-6 silica nanocomposite (Fe3O4@SiO2@ Kit-6-NH2) was synthesized as an adsorbent for removing Carmoisine food dye from aqueous solutions. Methods: The nanocomposite was chemically synthesized and was characterized by X-ray diffraction analysis (XRD), vibrating sample magnetometery (VSM), energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). Taguchi orthogonal array experimental design method was used to optimize the experimental conditions, including adsorbent amount, pH of the solution, amount of salt, the volume of sample and contact time. Pseudo first-order, pseudo second-order, intra-particle diffusion and Elovich kinetic models were investigated to study the kinetic parameters of the sorption process. Results: The kinetic data corresponded to the pseudo second-order kinetic model with R2 = 0.9999. Also, adsorption data were analyzed using Langmuir, Freundlich and Temkin isotherm models. The results indicated that the data were well fitted to the Freundlich isotherm model (R2 = 0.9984, n=1.0786). The reusability tests showed that the proposed nanocomposite could be used for more than 8 cycles with removal efficiency higher than 90%. Conclusion: The applicability study of the proposed nanocomposite proved its ability for efficient removal of Carmoisine dye from real aqueous samples.