A novel magnetic Preyssler acid grafted chitosan nano adsorbent: Synthesis, characterization and adsorption activity

BACKGROUND: This study concerns the application of magnetic heteropolyacids composite for the adsorption of organic compounds from aqueous solutions. A novel magnetic Preyssler/chitosan/Fe₃O₄ nanoparticles composite (PCNF) adsorbent was designed using a one-pot synthesis method and characterized by multiple techniques including X-ray powder diffraction (XRD), infrared spectroscopy (FT-IR), N₂ adsorption-desorption isotherms and scanning electron microscopy (SEM). RESULTS: The adsorption activity of PCNF was evaluated by the removal of methyl orange (as an anionic azo dye model, MO) from aqueous solution and all the factors influencing the removal efficiency, such as adsorbent dosage, initial dye concentration, and initial pH have been studied. Results show that the Langmuir adsorption and pseudo-first-order rate equations can well describe the adsorption of MO onto the PCNF surface. The maximum MO adsorption capacity for the PCNF was estimated to be 88.5 mg g^-1 at 45°C. CONCLUSIONS: The adsorption kinetic data of MO on PCNF are generally well described by the pseudo-first-order model, and it is shown that pore diffusion seems to be the limiting factor for the adsorption kinetics. The MO adsorption capacity obtained was higher than capacities found in the literature for various other adsorbents.