Abstract
The development of safe and cost-effective methods for the treatment of dye polluted wastewater has been a great concern among researchers. Herein, N-vinylpyrrolidon/chitosan/Fe3O4 (NVP/CS/Fe3O4) nanocomposite as a magnetic nano-adsorbent has been prepared by the in situ co-precipitation of iron salts in the CS/NVP hydrogel matrix. To study the various physical morphological and structural properties of the magnetic nanocomposites different characterization techniques such as IR, SEM, TEM, and XRD were applied. IR spectra confirmed the formation of magnetic nanoparticles through the appearance of the specific band at the wave number range of 400?500 cm-1. VSM study showed that in spite of embedding of magnetic nanoparticles with in the NVP/CS hydrogel network they are still super paramagnetic compared with the pare Fe3O4 nanoparticles. The NVP/CS/ Fe3O4 nanocomposite was used as sorbent for the removal of methyl orange (MO) as a model dye. Kinetic isotherm and diffusional behavior of the prepared NVP/CS hydrogels and their magnetic nanocomposites were also, studied. By examining the possibility of using the prepared hydrogels and magnetic nanocomposite for adsorption of MO the results showed that the adsorption processes depend on time, initial concentration, and dose of adsorbent. The pseudo-first order, pseudo second order and intra particle diffusion model used to evaluate the kinetics and the mechanism of the adsorption process where it is found that the second order kinetics describing well the adsorption process of MO dye using NVP/CS/Fe3O4 nanocomposite and the adsorption rate was controlled by various diffusion models not only intra particle diffusion.