纳米CeO_2吸附剂的制备及对六价铬的吸附性能  

Preparation of Nano-sized CeO_2 Adsorbents and Adsorption Ability for Hexavalent Chromium

作　　者：张金洋[1] 黄敏[1] 李琴 刘敏[1] 付孝锦[1] 雷光东[1] ZHANG Jin-yang;HUANG Min;LI Qin;LIU Min;FU Xiao-jin;LEI Guang-dong(College of Chemistry and Chemical Engineering,Neijiang Normal University,Neijiang 641100,China)

机构地区：[1]内江师范学院化学化工学院,内江641100

出　　处：《人工晶体学报》2018年第8期1662-1669,共8页Journal of Synthetic Crystals

基　　金：四川省教育厅重点项目(15ZA0290);四川省教育厅青年基金项目(11ZB179);国家大学生创新创业项目(X2017037)

摘　　要：吸附法是去除水中重金属离子的重要方法,开发新型吸附剂一直是研究热点。利用浸渍法和水热法制备了片状和无定形的纳米CeO_2吸附剂,探讨其对六价铬的吸附性能,分析pH、吸附时间、六价铬初始浓度等因素对其吸附性能的影响,并通过循环吸附实验考察纳米CeO_2吸附剂的再生能力。结果表明:厚度30 nm、直径大小约为400nm的片状CeO_2吸附剂具有更强的吸附能力和更快的吸附速率,80 min时基本达到吸附平衡;两种吸附剂的最佳吸附pH为3;吸附动力学均符合伪二级动力学方程,Langmuir模型和Freundlich模型均能很好地拟合等温吸附过程,表明纳米CeO_2对六价铬的吸附以单层吸附为主。片状CeO_2四次吸附-解吸实验之后吸附率稍有下降,表明片状CeO_2吸附剂有较好的再生能力,因而,该片状CeO_2吸附剂适用于与酸性Cr(Ⅵ)废水的处理。Adsorption is an important method to remove heavy metals in waste water.Development of new adsorbents is an important subject in research of adsorption technology.Two kinds of nano-sized CeO 2 adsorbents,flaky CeO 2 and amorphous CeO 2,were prepared by impregnation and hydrothermal methods.And their adsorption properties for hexavalent chromium(Cr(VI))were studied.The effects of pH,adsorption time and the concentration of Cr(VI)on the adsorption property were investigated.In addition,the regenerability of adsorbent was studied by cyclic adsorption experiment.The results show that flaky CeO 2 adsorbents with thickness of 30 nm and diameter of about 400 nm have better adsoption.The adsorption equilibrium is basically reached at 80 min.The most optimal pH of the two adsorbents is 3.The adsorption kinetics of both adsorbents were in accord with the pseudo-second-order kinetic equation.And the adsorption isotherms of both adsorbents were in accord with the Langmuir and Freundlich equation.It revealed that the adsorption of Cr(VI)by nano-sized CeO 2 was mainly monolayer adsorption.The adsorption rate of flaky CeO 2 decreases slightly after four times adsorption-desorption circulation,which indicated that CeO 2 adsorbent has good regeneration ability.Therefore,the flaky CeO 2 is suited for the treatment of acid wastewater containing Cr(VI).

关 键 词：片状CeO2 无定型CeO2 六价铬 吸附 

分 类 号：O782.1[理学—晶体学]