纳米结构Fe3O4/Y2O3磁性颗粒的制备、表征及磷吸附行为研究

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15.2nm.振动样品磁强计(VSM)测得比饱和磁化强度为38.7emu·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60.6mg·g-1(以P计);吸附速率较快,在120min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-

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

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-