Cd(Ⅱ)、Zn(Ⅱ)、Cu(Ⅱ)和Cr(Ⅲ)在钛酸纳米管上的吸附行为  

Adsorption of Cd( Ⅱ),Zn( Ⅱ),Cu( Ⅱ) and Cr( Ⅲ) onto titanate nanotubes

作　　者：韩云飞[1] 刘文[1,2] 王婷[2] 许楠[2] 

机构地区：[1]北京大学环境工程系,水沙科学教育部重点实验室,北京100871 [2]北京大学深圳研究生院环境与能源学院,深圳市重金属污染控制与资源化重点实验室,深圳518005

出　　处：《环境化学》2013年第11期2007-2015,共9页Environmental Chemistry

基　　金：国家水体污染控制与治理重大专项(2009ZX07212-001)资助

摘　　要：通过水热法以TiO2为原料合成了钛酸纳米管(TNTs),研究了Cd(Ⅱ)、Zn(Ⅱ)、Cu(Ⅱ)和Cr(Ⅲ)4种重金属在TNTs上的吸附行为,以及TNTs中钠含量对重金属吸附容量的影响.实验结果表明,制备的TNTs呈均一的管状结构,XRD分析证实TNTs为钛酸钠单斜型晶体且结晶较好.吸附实验表明,pH能显著影响重金属在TNTs上的吸附,最佳初始pH值为5—6;4种金属离子的吸附动力学过程符合准二级动力学模型,且30 min内即可达到平衡;等温吸附数据符合Langmuir方程(R2>0.9995),TNTs对4种重金属有很强的吸附能力,且吸附容量大小顺序为Q Cd(216.0 mg·g-1)>Q Zn(119.3 mg·g-1)≈Q Cu(114.8 mg·g-1)>Q Cr(75.3 mg·g-1).各种重金属的吸附量与TNTs中钠含量都呈较好的线性关系,相关系数(r)达0.913以上,说明钠离子在TNTs吸附重金属过程中起到了重要的作用.Titanate nanotubes （TNTs） were prepared via hydrothermal reaction with Ti02 as raw materials. Adsorption of Cd（Ⅱ）、Zn（Ⅱ）、Cu（Ⅱ） and Cr（-Ⅲ） onto TNTs was thoroughly studied, and the relation between adsorption capacity and sodium contents of TNTs was also investigated. The results showed that TNTs exhibited uniform tubular structure, and XRD analysis determined they were monoclinic phase. Bath adsorption results suggested that solution pH significantly affected adsorption capacities of Cd（Ⅱ）、Zn（Ⅱ）、Cu（Ⅱ） and Cr（-Ⅲ）, with an optimum pH range of 5--6. The pseudo-second-order model could well describe adsorption kinetics, and adsorption reached equilibrium within Langmuir isotherm model. Large adsorption capacities of the four heavy 30 min. The data were fit well by metals were found on TNTs, which ranked asQcd（216.0mg.g-1） 〉Qzn（ll9.3 mg.g-1） ~Qcu（ll4.8 mg-g-1） 〉Qcr（75.3 mg.g-1）. More importantly, adsorption capacity of the metals onto TNTs showed a good linear relationship with sodium contents of TNTs, with the correlation coefficient （r） up to 0. 913, which demonstrated that sodium ions played an important role in the adsorption process.

关 键 词：钛酸纳米管 吸附 重金属 钠含量 吸附容量 

分 类 号：X13[环境科学与工程—环境科学]