Synthesis and characterization of an adsorptive Schiff base-chitosan nanocomposite for removal of Pb(II) ion from aqueous media.

A new magnetic chitosan-(2-iminothiophenol methyl)benzaldehyde Schiff base-based adsorbent (MCS-ITMB) was synthesized to be effective adsorbent for adsorption of Pb from aqueous solutions. The adsorbent was characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), dynamic light scattering (DLS), vibrating sample magnetometer (VSM) and X-ray Diffraction (XRD). Batch adsorption experiments were done under various conditions, such as adsorbent dose, pH, and contact time. The equilibrium data were fitted to Langmuir and Freundlich isotherm models. The maximum monolayer capacity obtained from the Langmuir isotherm was 134.10 mg/g. The MCS-ITMB was found to be regenerated effectively up to five efficient cycles of adsorption/desorption processes. The mechanism for Pb adsorption onto MCS-ITMB involved the interactions of N, O and S atoms and also aromatic rings with heavy metal followed by their adsorption on the MCS-ITMB.