氧化锆-磁性壳聚糖对F^-的吸附性能研究

ADSORPTION OF FLUORIDE ION BY ZrO_2-MAGNETIC CHITOSAN

以氯化铁、壳聚糖、氧氯化锆等为原料,采用高温水热法制备了氧化锆负载的磁性壳聚糖纳米材料,并研究其对F^-的吸附行为。通过XRD对改性前后的磁性壳聚糖进行表征,发现氧化锆纳米颗粒成功包覆在磁性壳聚糖材料上且不影响磁性壳聚糖的晶型和骨架结构。吸附实验结果表明:氧化锆负载是提高F^-吸附量的关键因素,吸附机理包括离子交换和静电作用力;等温线可用Freundlich方程拟合;吸附动力学可用拟二级动力学模型拟合。适当升高温度有利于吸附的进行,吸附量随pH值的升高而降低,共存离子Cl^-、NO_3^-和SO_4^(2-)对吸附几乎没有影响。经过5次脱附再生后吸附剂仍有70.33%的吸附量,表明在实验范围内,该吸附剂再生性好,可循环使用。

Magnetic chitosan nanomaterials loaded by ZrO_2 were prepared by high temperature hydrothermal method with ferric chloride,chitosan,zirconium oxychloride and other raw materials. The adsorption behavior of magnetic chitosan on F-was investigated. The adsorbent was characterized by XRD. The results showed that the loading of zirconia did not affect the crystalline phase and skeleton of magnetic chitosan. Adsorption experiment indicated that MCS-Zr had high removal efficiency for F-because of ion exchange and electrostatic interaction. The adsorption isotherm could be well described by the Freundlich adsorption model and the adsorption kinetic on MCS-Zr followed Pseudo-second-order kinetics. The proper increase of temperature was beneficial to the adsorption. The adsorption capacity decreased with the increase of solution pH. The coexisting ions Cl^-、NO_3^- and SO_4^（2-） had no effect on adsorption. After five-time desorption regeneration,the adsorbent still had 70. 33% of the original adsorption capacity,indicating that the adsorbent had good reproducibility and could be recycled in the experimental range.