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研究报告

李国亮,张高生,陈静,任宗明,陈琳琳.纳米结构Fe₃O₄/Y₂O₃磁性颗粒的制备、表征及磷吸附行为研究[J].环境科学学报,2012,32(9):2167-2175

Preparation and characterization of Fe₃O₄/Y₂O₃ magnetic particle with nano-structure and its phosphate adsorption properties

摘要：采用共沉淀法制备了一种新型铁钇氧化物(Fe₃O₄/Y₂O₃)磁性吸附剂, 并对其表面特性及磷吸附行为进行了初步研究. 扫描电镜(SEM)与X-射线衍射仪(XRD)表征结果表明,此吸附剂具有纳米结构,初级粒子平均粒径为15.2 nm. 振动样品磁强计(VSM)测得比饱和磁化强度为38.7 emu·g^-1,磁性较强,可方便地实现固液分离. 吸附剂的等电点为6.8. 磷吸附实验表明, 25 ℃时, Langmuir吸附等温线可较好地拟合Fe₃O₄/Y₂O₃对溶液中磷的吸附(R²=0.989), 最大吸附量(pH=5.0)为60.6 mg·g^-1(以P计); 吸附速率较快, 在120 min内可完成吸附容量的80%以上, 符合准二级动力学模型(R²=0.997); 溶液pH对Fe₃O₄/Y₂O₃吸附磷的影响较为明显, 离子强度则影响不大; 共存阴离子对吸附影响的大小顺序为Cl^- < SO₄^2- < CO₃^2-< SiO₃^2-.

Abstract：Fe₃O₄/Y₂O₃, a novel magnetic adsorbent, was prepared by co-precipitation process and its properties were investigated. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis indicate that this adsorbent is formed with nano-structured fine particles with average primary particle size of 15.2 nm. The specific saturation magnetization is 38.7 emu·g^-1 measured by vibrating sample magnetometer (VSM) and the isoelectric point is 6.8. Batch sorption experiment data is well fitted with Langmuir model (R²=0.989) with maximal phosphate adsorption capacity of 60.6 mg·g^-1 at 25℃ and pH 5.0. The adsorption kinetic data is well described by pseudo-second order model (R²=0.997) and over 80% of the equilibrium adsorption capacity is achieved within 120 min. The phosphate adsorption is dependent on solution pH, while ionic strength poses little effect. The effect of coexisting anions on phosphate adsorption on Fe₃O₄/Y₂O₃ increases in the order of Cl^-＜SO₄^2-＜CO₃^2-＜SiO₃^2-.