Adsorption study of eosin yellow and fluorescein dyes from aqueous solution using chitosan schiff base/polyvinyl acetate and its Fe2O3 nanocomposite

Chitosan Schiff base/polyvinyl acetate (CSB/PVAc) and its Fe2O3 (CSB/PVAc@Fe2O3) nanocomposite were fabricated and characterized using different techniques, including FT-IR, XRD, SEM/EDS, BET, TGA, and DSC. They were used as suitable adsorbents for removing eosin yellow (EY), and Fluorescein (FS) dyes from the aqueous solution. The adsorption experiments were optimized by varying the essential parameters: pH solution, adsorbent dose, and contact time. Under optimum conditions (pH = 3 and 0.02 g dose of sorbents), the maximum removal efficiency was 75.65% and 95.53% for EY and 80.51% and 93.46% for FS using CSB/PVAc and CSB/PVAc@Fe2O3, respectively. Kinetic studies used pseudo-first-order, pseudo-second-order, and intra-particle diffusion models. The experimental data obeyed the intra-particle diffusion model. The adsorption data were analyzed using the Langmuir and Freundlich isotherms. According to the results, the experimental data fitted well with the Freundlich model as a heterogenous process. Finally, the removal efficiency of the new adsorbet CSB/PVAc@Fe2O3 become less active (< 7%) towards EY and FS dyes after 5 runs.