硅藻土改性及其在硫酸锌溶液中脱氟性能

Diatomite Modification and Fluoride Removal from Zinc Sulfate Solution

采用浸泡—焙烧负载元素铝的方法对硅藻土进行改性,研究改性硅藻土对硫酸锌溶液中氟的吸附性能,并利用EDX能谱分析、扫描电镜(SEM)及X射线衍射仪(XRD)对硅藻土和改性硅藻土的成分、形貌及微观结构等进行表征。结果表明,硅藻土改性对于提高其在硫酸锌溶液中的脱氟性能效果明显,在改性硅藻土投加量15g/L、吸附时间30min、pH=4、温度45℃的条件下,其吸附效果最佳,溶液中的氟离子浓度由180mg/L降低到78.56mg/L,脱氟率达到了56.36%;EDX、SEM及XRD分析结果表明,改性硅藻土表面有效负载了铝元素且其杂质元素含量明显减少,孔径明显增大,这对于硅藻土脱氟性能的提高十分有利。

The diatomite is modified by the soaking- roasting method loaded by aluminum. The adsorption capability of fluorine in the zinc sulfate solution is studied by the modified diatomite. The component,feature and structure of the modified diatomite are characterized by EDX,SEM and XRD.The results show that the absorption efficiency of fluorine in the zinc sulfate solution can be obviously upgraded by the modification of the diatomite. Under the conditions of 15 g / L modified diatomite dosage,30 min adsorption time,pH value of 4 and 45 ℃,the optimal absorption efficiency is obtained,the fluorion concentration in the solution is reduced from 180 mg / L to 78. 56 mg / L,and the removal ratio of fluorine reaches 56. 36%. It is indicated by the results of the EDX,SEM and XRD that the surface of modified diatomite is loaded by aluminum effectively,the content of impurity is decreased and bore diameter of modified diatomite is increased. So the removal capability of fluorine is improved.