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采用一步溶剂热法合成了磁性壳聚糖微球(Fe3O4@CS),并对所制备的样品进行了表征。结果表明:Fe3O4@CS微球尺寸为220~250 nm,比饱和磁化强度>38.5 A.m2/kg,且随着壳聚糖含量的增加,样品的饱和磁化强度与单分散性降低。考察了Fe3O4@CS对Hg2+的吸附性能,结果显示,Fe3O4@CS对Hg2+的最大吸附量为0.83 mmol/g,其对Hg2+的吸附能力归因于样品表面暴露的官能团的数量及单分散性的共同影响:样品壳聚糖含量的增加,会增加表面的氨基和羟基的数量,有助于对Hg2+的吸附;反之样品壳聚糖含量增加,表面官能团电荷增多易团聚,又会降低对Hg2+的吸附。在动力学吸附实验中,样品在10 min内即可达到吸附平衡,表明该吸附剂具有快速的吸附能力;同时可通过外加磁场对吸附剂进行分离,被吸附的Hg2+用乙二胺四乙酸二钠(EDTA-2Na)很容易被洗脱,因此该吸附剂具有良好的循环利用能力。
Magnetic chitosan microspheres (Fe3O4 @ CS) were synthesized by one-step solvothermal method and the prepared samples were characterized. The results show that the Fe3O4 @ CS microspheres have a size of 220-250 nm and a specific saturation magnetization> 38.5 A.m2 / kg. The saturation magnetization and monodispersity decrease with the increase of the content of chitosan. The adsorption capacity of Hg2 + by Fe3O4 @ CS was investigated. The results showed that the maximum adsorption capacity of Hg2 + by Fe3O4 @ CS was 0.83 mmol / g. The adsorption capacity of Hg2 + was attributed to the number of functional groups exposed on the surface of the sample and the monodispersity Together, the increase of sample chitosan content will increase the number of amino groups and hydroxyl groups on the surface and help to adsorb Hg2 +. On the contrary, when the content of chitosan in sample increases and the surface functional group charge increases and agglomeration easily occurs, the Hg2 + Adsorption. In the kinetic adsorption experiment, the sample can reach the equilibrium of adsorption within 10 min, indicating that the adsorbent has a fast adsorption capacity; at the same time, the adsorbent can be separated by an applied magnetic field; the adsorbed Hg2 + Sodium (EDTA-2Na) is easily eluted, so the adsorbent has good recycling ability.