Removal of Pb(II) ions and ethidium bromide from aqueous solution using novel magnetic chitosan-based Schiff base...

Schiff bases compounds can be used for the removal of heavy metal ions from water due to their chelating properties. In this work, magnetic chitosan-(2-imino-3-hydroxypiridine methyl benzaldehyde (MCS-IHPMB) was synthesized and applied in an aqueous solution to remove Pb(II) ions and ethidium bromide (EBr). MCS-IHPMB structural characteristics were studied by spectroscopic analysis including FT-IR, VSM, XRD, SEM, EDX, DLS, and TGA. Batch adsorption experiments were done under various conditions including initial concentrations of dye and metal ion, contact time, pH, and adsorbent dose. Equilibrium data were fitted to kinetic and isotherm models while theoretical calculations were performed to gain insight into adsorption mechanism. The pseudo-second order model well represented the kinetic data. Both for EBr and for Pb(II), the adsorbent performance was in good agreement with the Langmuir isotherm. The adsorption capacity exhibited by the MCS-IHPMB towards Pb(II) and EBr were 200.11 and 147.78 mg/g, respectively. The results obtained were also confirmed by simulation calculations. The adsorption/desorption experiments were done, and the results showed that the MCS-IHPMB still had an adequate absorption efficiency after several times (five times) consecutive applications. All of these features, including fast and easy synthesis, low cost, and reusability, make the MCS-IHPMB practical application promising.