Efficient removal of phosphate from aqueous solution using novel magnetic nanocomposites with Fe3O4@SiO2 core and mesoporous CeO2 shell
来源期刊：JOURNAL OF RARE EARTHS2017年第10期
论文作者：丁鸿 赵燕凌 段倩林 王俊文 张侃 丁光月 谢鲜梅 丁传敏
文章页码：984 - 994
摘 要：Fe3O4@SiO2 magnetic nanoparticles functionalized with mesoporous cerium oxide（Fe3O4@SiO2@mCeO2） was fabricated as a novel adsorbent to remove phosphate from water. The prepared adsorbent was characterized by X-ray diffractometry（XRD）, transmission electron microscopy（TEM）, nitrogen adsorption-desorption and vibrating sample magnetometry（VSM）, and its phosphate removal performance was investigated through the batch adsorption studies. Characterization results confirmed that mesoporous cerium oxide was successfully assembled on the surface of Fe3O4@SiO2 nanoparticles, and the synthesized adsorbent possessed a typical core-shell structure with a BET surface area of 195 m2/g, accessible mesopores of 2.6 nm, and the saturation magnetization of 21.11 emu/g. The newly developed adsorbent had an excellent performance in adsorbing phosphate, and its maximum adsorption capacity calculated from the Langmuir model was 64.07 mg/g. The adsorption was fast, and the kinetic data could be best fitted with the pseudo-second-order kinetic model. The phosphate removal decreased with the increase of solution pH（2 to 10）, while the higher ionic strength slightly promoted the phosphate adsorption. The presence of Cl– and SO2–4 could enhance the adsorption of phosphate whereas HCO– 3 had interfering effect on the phosphate adsorption. The adsorption mechanism was studied by analyzing Zeta potential and FTIR spectroscopy, and the results indicated that the replacement of the surface hydroxyl groups by phosphate ions with the formation of inner-sphere complex played a key role in the phosphate adsorption. The spent adsorbent could be quickly separated from aqueous solution with the assistance of the external magnetic field, and the adsorbed phosphate could be effectively desorbed using a 1 mol/L NaOH solution.
丁鸿1，赵燕凌1,2，段倩林1，王俊文1，张侃3，丁光月1，谢鲜梅1，丁传敏1
1. College of Chemistry and Chemical Engineering, Taiyuan University of Technology2. Department of Medical Imaging, Shanxi Medical University3. State Key Laboratory of Coal Conversion, Institute of Coal Chemistry of CAS
摘 要：Fe3O4@SiO2 magnetic nanoparticles functionalized with mesoporous cerium oxide（Fe3O4@SiO2@mCeO2） was fabricated as a novel adsorbent to remove phosphate from water. The prepared adsorbent was characterized by X-ray diffractometry（XRD）, transmission electron microscopy（TEM）, nitrogen adsorption-desorption and vibrating sample magnetometry（VSM）, and its phosphate removal performance was investigated through the batch adsorption studies. Characterization results confirmed that mesoporous cerium oxide was successfully assembled on the surface of Fe3O4@SiO2 nanoparticles, and the synthesized adsorbent possessed a typical core-shell structure with a BET surface area of 195 m2/g, accessible mesopores of 2.6 nm, and the saturation magnetization of 21.11 emu/g. The newly developed adsorbent had an excellent performance in adsorbing phosphate, and its maximum adsorption capacity calculated from the Langmuir model was 64.07 mg/g. The adsorption was fast, and the kinetic data could be best fitted with the pseudo-second-order kinetic model. The phosphate removal decreased with the increase of solution pH（2 to 10）, while the higher ionic strength slightly promoted the phosphate adsorption. The presence of Cl– and SO2–4 could enhance the adsorption of phosphate whereas HCO– 3 had interfering effect on the phosphate adsorption. The adsorption mechanism was studied by analyzing Zeta potential and FTIR spectroscopy, and the results indicated that the replacement of the surface hydroxyl groups by phosphate ions with the formation of inner-sphere complex played a key role in the phosphate adsorption. The spent adsorbent could be quickly separated from aqueous solution with the assistance of the external magnetic field, and the adsorbed phosphate could be effectively desorbed using a 1 mol/L NaOH solution.
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