纳米零价铁强化高岭石去除水中Cr(Ⅵ)及机制研究  

Removal of Chromate(Ⅵ)from Water Using Kaolinite Enhanced by Nano-Zero-Valent Iron and Its Mechanism

作　　者：刘柳 胡佩伟[1,2] 高润琴 程港莉 姚瑶 LIU Liu;HU Peiwei;GAO Runqin;CHENG Gangli;YAO Yao(College of Resources and Environment Engineering,Wuhan University of Science and Technology,Wuhan 430081,China;Hubei Key Laboratory for Efficient Utilization and Agglomeration of Metallurgic Mineral Resources,Wuhan 430081,China)

机构地区：[1]武汉科技大学资源与环境工程学院,武汉430081 [2]冶金矿产资源高效利用与造块湖北省重点实验室,武汉430081

出　　处：《硅酸盐通报》2021年第5期1529-1535,1544,共8页Bulletin of the Chinese Ceramic Society

基　　金：湖北省教育厅科学技术研究重点项目(D20191106);国家自然科学基金(51304149);国家级大学生创新创业训练计划(201810488021);武汉科技大学大学生创新训练计划(20ZA076)。

摘　　要：纳米零价铁(nZVI)作为一种治理重金属、核素污染物的环保材料而被广泛关注,而黏土矿物作为常见的重金属吸附材料虽成本低廉、来源广泛,但去除性能又普遍有限。通过液相还原法制备nZVI/高岭石复合材料来强化高岭石去除水中Cr(Ⅵ)的性能,利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)技术对其结构进行表征,考察了Cr(Ⅵ)初始浓度、nZVI/高岭石投加量、温度等条件对Cr(Ⅵ)去除率的影响,并探讨了其对水中Cr(Ⅵ)的去除能力及机制。结果表明,nZVI/高岭石中的nZVI结晶度低,粒径在50~100 nm, nZVI/高岭石在60 min时对Cr(Ⅵ)的去除率达91.7%,分别比nZVI和高岭石提高了2.7倍和18.5倍。nZVI/高岭石对Cr(Ⅵ)的去除动力学符合准二级动力学模型,表观反应活化能为27.97 kJ/mol,去除是吸附、还原和共沉淀共同作用的结果。通过nZVI强化可提升高岭土在水处理和环境修复中的应用前景。Nano-zero-valent iron(nZVI)has received widely attention as an environmental protection material for the treatment of heavy metal and nuclide pollutants.Clay mineral,as a common heavy metal adsorption material,has low cost and wide sources,but its removal performance is generally limited.nZVI/Kao(nZVI/kaolinite)was prepared by liquid phase reduction method for the efficient removal of Cr(Ⅵ)from water.XRD,SEM and TEM were used to characterize the phase and structure of the composite.The effects of Cr(Ⅵ)initial concentration,nZVI/Kao dosage and temperature on the removal rate of Cr(Ⅵ)by the composite were studied.Meanwhile,the removal ability and mechanism of Cr(Ⅵ)from water were also discussed.The results show that nZVI has the low crystallinity and its particle size is between 50 nm and 100 nm.The Cr(Ⅵ)removal rate of the nZVI/Kao is 91.7%in 60 min,which is 2.7 times and 18.5 times than that of the single nZVI and kaolinite,respectively.The removal kinetics fits well with the pseudo-second order kinetic model and the apparent activation energy is 27.97 kJ/mol.The removal process is the result of common action of adsorption,reduction and co-precipitation.The application prospect of kaolin in water treatment and environmental remediation can be strengthened by loading nZVI.

关 键 词：高岭石 纳米零价铁 液相还原法 铬 动力学模型 去除率 

分 类 号：TD985[矿业工程—选矿]