Efficient removal of Cd(II) by core-shell Fe3O4@polydopamine microspheres from aqueous solution

In this study, the functional core-shell structure Fe3O4@PDA microspheres with strong saturation magnetism was successfully prepared by in-situ polymerization method. The microstructures, morphologies and chemical components of obtained samples were systematically analyzed. The maximum removal capacity of Fe3O4@PDA microspheres towards Cd(II) was 296.4 mg·g−1 at 298 K. The removal process of Cd(II) conformed pseudo-second-order kinetic model well. In addition, the significant effects of pH and ionic strength on the adsorption performance were also researched by batch adsorption experiment. Furthermore, the adsorption capacity of Fe3O4@PDA remained at a relatively high level after five cycles, which implied that it possessed high reusability as an adsorbent. Therefore, the prepared Fe3O4@PDA microspheres could be recognized as excellent adsorbents for Cd(II) removal from polluted water.