Preparation of magnetic core-shell Ce-doped zirconia and its As(III) adsorption properties
(1. Jiangsu Key Laboratory of Resources and Environmental Information Engineering, China University of Mining and Technology, Xuzhou 221116, China;
2. School of Chemical Engineering, The University of Queensland, St Lucia, Queensland 4072, Australia;
3. Nanjing Zhuoze Water Conservancy Technology Co., Ltd., Nanjing 210000, China)
2. School of Chemical Engineering, The University of Queensland, St Lucia, Queensland 4072, Australia;
3. Nanjing Zhuoze Water Conservancy Technology Co., Ltd., Nanjing 210000, China)
Abstract: 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 m2/g) and fast magnetic separation performance (5.37 A·m2/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 and weakened As(III) adsorption, Ca2+ worked oppositely, but the impact of Cl- and 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.
Key words: core-shell structure; magnetism; cerium doping; zirconia; As(III) adsorption