Simultaneous removal of Pb(II) and Cr(III) by magnetite nanoparticles using various synthesis conditions

This study concerns the removal of Pb(II) and Cr(III) using magnetite nanoparticles synthesized by coprecipitation methods with (NCM) or without (CM) nitrogen gas passing through. Removal of Pb(II) significantly decreased from 80.56 to 41.41% when Cr(III) was co-presented, while decrease of Cr(III) was negligible when Pb(II) was present, falling from 42.37 to 38.48%. The characterizations indicated that the removal mechanism occurred through adsorption rather than chemical redox reaction. A co-adsorption mechanism is based on Pb(II) involved surface complexation, while Cr(III) was firstly adsorbed onto magnetite, followed by a partially substitution of Cr(III) for Fe(III) in Cr-Fe3O4 through ion exchanges. Refereed/Peer-reviewed