Mg-Al水滑石的制备及对水中氟离子的吸附效果研究  

Preparation of Mg-Al hydrotalcite and its adsorption effect onfluoride ions in water

作　　者：邹志鑫 李敏 任晓影 刘佳惠 焦桂萍 赵瀛 ZOU Zhixin;LI Min;REN Xiaoying;LIU Jiahui;JIAO Guiping;ZHAO Ying(The 718th Research Institute of CSSC,Handan 056000,China)

机构地区：[1]中国船舶集团有限公司第七一八研究所,河北邯郸056000

出　　处：《功能材料》2024年第4期4179-4184,4200,共7页Journal of Functional Materials

基　　金：国家自然科学基金项目(52015012);河北省军民融合科技创新项目(JMRH-JHSB-2021-01)。

摘　　要：通过共沉淀法制备了Mg-Al水滑石,研究了镁铝摩尔比对Mg-Al水滑石的晶格结构、微观形貌、光谱性能的影响。以NaF溶液为模拟含氟废水,测试了Mg-Al水滑石对水中氟离子的吸附量和去除率,通过吸附模型研究了相应的吸附过程和机理。结果表明,Mg-Al水滑石外观为片层状结构,片层之间相互交叉堆积,镁铝比增大时,Mg-Al水滑石的层间距增大。水滑石对氟离子的饱和吸附量和去除率随着镁铝比的增大表现出先增大后减小的趋势,在吸附80 min时吸附量接近饱和,3Mg-Al水滑石的饱和吸附量达到最大值43.16 mg/g,去除率在120 min时达到最大值90.5%,经过5次吸附再生循环使用后,3Mg-Al水滑石对氟离子的去除率降至69.4%,保持率达到76.69%,具有良好的可重复利用性能。通过对Mg-Al水滑石吸附氟离子的数据进行拟合,发现Mg-Al水滑石吸附氟离子的过程更符合准二级动力学模型,主要以化学吸附作用为主。This article prepared Mg-Al hydrotalcite through coprecipitation method,and studied the effect of magnesium aluminum molar ratio on the lattice structure,microstructure and spectral properties of Mg-Al hydrotalcite.Using NaF solution as a simulated fluorine-containing wastewater,the adsorption capacity and removal rate of Mg-Al hydrotalcite on fluoride ions in water were tested.The corresponding adsorption process and mechanism were studied through adsorption models.The research results indicate that the appearance of Mg-Al hydrotalcite is a layered structure,with interlaminar stacking between layers.As the magnesium aluminum ratio increases,the interlayer spacing of Mg-Al hydrotalcite increases.The saturated adsorption capacity and removal rate of fluoride ions by hydrotalcite show a trend of first increasing and then decreasing with the increase of magnesium aluminum ratio.The adsorption capacity approaches saturation at 80 minutes,and the saturated adsorption capacity of 3Mg-Al hydrotalcite reaches the maximum value of 43.16 mg/g.The removal rate reaches the maximum value of 90.5%at 120 min.After 5 cycles of adsorption regeneration,the removal rate of fluoride ions by 3Mg-Al LDH decreased to 69.4%,and the retention rate reached 76.69%,demonstrating good reusability.By fitting the adsorption data of fluoride ions by hydrotalcite,it is shown that the adsorption process of fluoride ions by Mg-Al hydrotalcite is more consistent with the quasi-second-order kinetic model,which is mainly based on chemisorption.

关 键 词：MG-AL 水滑石 共沉淀法 氟离子 再生循环 吸附动力学 

分 类 号：X703[环境科学与工程—环境工程]