Fabrication of Fe3O4@cyclodextrin magnetic composite for the high-efficient removal of Eu(III)

In this study, the Fe3O4@CD MCs were synthesized by using a simple chemical co-precipitation method for the removal of Eu(III) from aqueous solutions. Compared with Fe3O4, the prepared Fe3O4@CD MCs exhibited higher sorption amount toward Eu(III). In addition, Fe3O4@CD MCs could be easily separated from aqueous solutions by using magnetic separation technique at low magnetic field gradients. The sorption properties of Fe3O4@CD MCs toward Eu(III) were investigated by using a batch technique under environmental conditions. The sorption kinetics of Eu(III) on Fe3O4@CD MCs could achieve equilibrium in a time period of 3 h. The pH-dependent and ionic strength-independent Eu(III) sorption on the surface of Fe3O4@CD MCs demonstrated that the sorption mechanism of Eu(III) was inner-sphere surface complexation at low pH, whereas the removal of Eu(III) was achieved by simultaneous precipitation and inner-sphere surface complexation at high pH values. The Langmuir and Freundlich patterns were employed to simulate sorption isotherms of Eu(III) on Fe3O4@CD MCs. Considering the low cost, simple synthesis procedure, high removal efficiency, easy separation and environmental friendliness, it is expected that Fe3O4@CD MCs can be used as a cost-effective material for the purification of Eu(III)-bearing effluents.