纳米CeO_(2)辅助改性γ-Al_(2)O_(3)对水中氟离子的吸附研究

Adsorption of fluoride ions in water by nano-CeO_(2) assisted modificationγ-Al_(2)O_(3)

为高效去除水中氟离子(F^(-)),采用化学浸渍法制得载铈活性氧化铝(CA)及水热法研制CeO_(2)纳米材料(CNM),以物理混合法将CNM引入CA(CA@CNM)以辅助CA对F^(-)进行吸附研究。采用BET、SEM、XRD和FTIR对材料进行表征和机理分析。静态试验研究了CA及CA@CNM的除氟性能,结果显示CA@CNM除氟效果较CA更好,吸附过程更稳定,吸附时间更短,最佳吸附条件为:吸附时间1 h,总投加量2 g/L,CA与CNM的质量比3∶1,pH 7。CA@CNM除氟符合准二级动力学方程,Freundlich和D-R吸附等温模型,表明该吸附主要为多层化学吸附和离子交换作用。探讨了共存阴离子对除氟效果的影响,为后期实际应用提供理论和应用基础。

In order to efficiently remove fluoride ions from water,CeO_(2)nanomaterials(CNM)were prepared by chemical impregnation method and hydrothermal method.CNM was introduced into CA(CA@CNM)by physical mixing to assist its adsorption of fluoride ions.The materials were characterized by BET,SEM,XRD and FTIR.Static experiments were carried out to study the fluorine removal performance of CA and CA@CNM.The results showed that the fluorine removal effect of CA@CNM was better than that of CA,the adsorption process was more stable and the adsorption time was shorter.The optimal adsorption conditions were as follows:adsorption time 1 h,total dosage 2 g/L,mass ratio of CA to CNM 3∶1,pH 7.The fluoride removal of CA@CNM conforms to the pseudo-second-order kinetic equation,Freundlich and D-R adsorption isotherm models,indicating that the adsorption is mainly multi-layer chemical adsorption and ion exchange.The influence of coexisting anions on fluorine adsorption was discussed,which provided theoretical and application basis for later application.