Design and synthesis of core-shell Fe3O4@PTMT composite magnetic microspheres for adsorption of heavy metals from high salinity wastewater.

In this study, a novel magnetic nanoparticles (MNP) modified by an organodisulfide polymer (PTMT) was designed for adsorption of heavy metals (Hg(II), Pb(II) and Cd(II)) from simulated coal chemical high salinity wastewater. The MNP-PTMT nano-composite was synthesize and characterized by SEM, TEM, FTIR, BET, VSM, TGA and XRD. The results indicate that the wanted MNP-PTMT magnetic nanoparticles were successfully obtained by modification. Adsorption experiments were systematically carried out to evaluate the performance of the obtained nanoparticles and to build up the adsorption models. The results demonstrate that the adsorption kinetic and isotherms thermodynamic followed the pseudo-second-order model and the Freundlich equation, respectively. In the presence of the inorganic salt in high salinity wastewater, the adsorption efficiency of MNP-PTMT for heavy metals was still excellent. The magnetic adsorbent could be recovered from aqueous solution by an external magnetic field in 20s and the subsequent regeneration of Hg(II)/Pb(II) loaded MNP-PTMT can be efficiently achieved by using EDTA-2Na solution as desorbent. The novel MNP-PTMT nanoparticles could be used reproductively for five times without apparent decrease in sorption capacity.