氧化铁改性蛭石的制备、表征及吸附氟的特性（英文）  

Preparation,Characterization and Fluoride Adsorption Characteristics of Iron-Oxide-Modified Vermiculite

作　　者：魏世勇[1] 王锐[1] 牛鹏举 方敦[1] 杨小洪[1] 但悠梦[1] 

机构地区：[1]湖北民族学院化学与环境工程学院生物资源保护与利用湖北省重点实验室,恩施445000

出　　处：《无机化学学报》2016年第9期1619-1628,共10页Chinese Journal of Inorganic Chemistry

基　　金：国家自然科学基金(No.41261060,41561053);生物资源保护与利用湖北省重点实验室开放基金(No.PKLHB1315)资助项目

摘　　要：采用共沉淀法制备了3种不同含铁量的氧化铁改性蛭石（Verm-Fex,x=5,10,20）,研究了纯蛭石（Verm）和Verm-Fex的表面性质及吸附氟的特性。与样品Verm比较,3种Verm-Fex中Verm的d（002）层间距略有升高;Verm-Fex的孔体积、表面积、表面分形度均随含铁量的增加而升高,其中微孔体积和外表面积的增加幅度更明显。4种样品的等电点（IEP）也随含铁量的增加而明显升高;初始p H=5.0时,它们的表面ζ电位分别为-16.4,-6.1,10.5和28.4 m V。4种样品对氟的等温吸附数据用单吸附位Langmuir模型拟合（R2=0.973～0.995）时,Verm的R2最高;双吸附位Langmuir模型可很好地描述3种Verm-Fex样品的等温吸附过程（R2=0.991～0.998）;Freundlich模型对4种样品吸附数据的拟合度较差（R2=0.835～0.937）,但R2随样品含铁量的增加而略微升高。初始p H=5.0时,Verm和Verm-Fex（x=5,10,20）对氟的最大吸附容量（qmax）分别为3.18,6.76,9.27和12.43 mg·g-1。可见,Verm-Fex（尤其含铁量较高的产物）对表生环境中氟的吸附固定性能明显高于Verm。Iron-oxide-modified vermiculite（Verm-Fex,x=5,10,20） was prepared by a co-precipitation procedure.The surface properties and fluoride adsorption of pure vermiculite（Verm） and Verm-Fexwere investigated.Compared to Verm,the d（002）spacing of Verm in Verm-Fexincreases slightly,and the pore volumes,different surface areas and surface fractal dimension of Verm-Fexincrease with increasing the Fe contents.The increased magnitude of the micropore volume and external surface area of Verm-Fexis more significant.The isoelectric point（IEP） of the samples increases in the order of Verm 〈Verm-Fe5 〈Verm-Fe10〈 Verm-Fe20,and the ζpotential at p H 5.0 of the four samples is-16.4,-6.1,10.5,and 28.4 m V,respectively.One-site Langmuir model was used to describe the fluoride adsorption by the samples（R2=0.973～0.995）,and the determination coefficient（R2） for Verm is the highest.The R2 fitted from two-site model for Verm-Fex（x=5,10,20） is higher than that from one-site model,indicating that the adsorption data of Verm-Fexcan be fitted by two-site model well.The R2 fitted from Freundlich model of the samples is lying in the range of 0.835～0.937 and follows the sequence of Verm Verm-Fe5〈 Verm-Fe10〈 Verm-Fe20.This indicates that Verm-Fexpossesses the heterogeneous surfaces with different reactive sites.When p H=5.0,the adsorption capacities（qmax） of Verm,Verm-Fe5,Verm-Fe10 and Verm-Fe20 are 3.18,6.76,9.27 and 12.43 mg·g-1,respectively.Compared to Verm,Verm-Fexwith a high Fe content has a higher adsorption capacity for fluoride in solutions.

关 键 词：蛭石 氧化铁改性蛭石 表面性质 吸附 氟 

分 类 号：O614.81[理学—无机化学] S153.6[理学—化学]