Preparation of magnetic core-shell Ce-doped zirconia and its As(III) adsorption properties

A new magnetic mesoporous As(III) adsorbent of Fe3O4@SiO2@Ce-ZrO2 was prepared by solvothermal and sol-gel method. The core-shell adsorbent presented a high specific surface area (168.2 m(2)/g) and fast magnetic separation performance (5.37 A.m(2)/kg). Compared with Fe3O4@SiO2@ZrO2, the Ce-doped sample exhibited 12%-23% increase in As(III) uptake over pH 3-11, which was mainly attributed to the formation of bimetal M-O-As complexes. The coexisted SO42- and PO43- weakened As(III) adsorption, Ca2+ worked oppositely, but the impact of Cl- and NO3- was negligible. The As(III) maximum adsorption capacity was 24.52 mg/g at 313 K with an initial As(III) concentration of 5 mg/L at pH 7, and its kinetics was well fitted by the pseudo-second-order model. Moreover, the adsorbent exhibited remarkable recyclability. It is suggested that Fe3O4@SiO2@Ce-ZrO2 is a promising adsorbent for the advanced treatment of As(III) contaminated wastewater.