有机改性膨润土对某些金属离子吸附的系列研究

【作者】 王永好；

【导师】 陈建中；

【作者基本信息】 福州大学 ， 物理化学， 2004， 硕士

【摘要】 本文介绍了膨润土以及有机膨润土的性质及其在环境保护方面的应用研究进展，重点讨论了有机膨润土对几种重金属离子的吸附，展望了有机膨润土在环境保护方面的应用前景。 本文采用湿法合成了阳离子表面活性剂改性的膨润土和阴－阳离子表面活性剂改性的膨润土，探讨了两种有机膨润土对几种离子的吸附条件，在最佳条件下，膨润土原土对三种离子的去除率的顺序是Pb2+≈Cu2+＞Cr(VI)，对阳离子的去除率达到88％以上，而对六价铬的去除率却只有49.9％；两种有机膨润土对两种阳离子的去除率都到了97％以上，对六价铬就不同了，1827土对六价铬的去除率是94.9％，而SDS土对六价铬的去除率仅为60.3％。离子吸附的动力学研究表明不同的离子对不同的动力学方程具有较显著的拟合水平。根据相关的方程求出活化熵、活化焓以及活化自由能等一系列的假热力学参数。离子间的竞争吸附的研究表明，Cu2+为低浓度时，不论Cr(VI)是高浓度还是低浓度都不会对Cu2+的吸附产生竞争，而当Cu2+为高浓度时，不论Cr(VI)是高浓度还是低浓度都会对Cu2+的吸附产生竞争；对于高浓度和低浓度的Cr(VI)，不论Cu2+是高浓度还是低浓度都对Cr(VI)的吸附产生竞争，不同的是产生竞争时的pH不同。Cu2+和Pb2+的竞争吸附表明，低浓度时，二者在实验的pH范围内都被吸附，竞争不明显；高浓度时，在pH小于6时存在明显的竞争。综合各种实验数据及理论分析，改性膨润土在环境保护，特别是废水处理及环境修复中的应用具有重大意义，用于环境污染治理将有广阔的应用前景。更多还原

【Abstract】 The properties and applications of organobentonites in environmental protection were described. The adsorption of metal ions from water by organobentonites was reviewed. The application of organobentonites in wastewater treatment and remediation of polluted environment were also forecasted.Novel modified bentonites were prepared by liquid-phase reaction by using cationic surfactant and cationic-anionic surfactants as ion exchanger. The conditions of ion adsorption were investigated. The results show that bentonite and organobentonites have great ion-adsorption capacities at pH=2 and pH=5.5-6 respectively. The reaction kinetics of organobentonite for the removal of metal ions from solution has been investigated. Different kinetic equations were used to fit the dynamic process of different ion adsorption. The parameters, i.e. adsorption activation energy, activation entropy, activation enthalpy and activation free energy were calculated by relative kinetic equation.Investigation was conducted to evaluate the competitive adsorption of Cu2+ Pb2+ and Cr(VI) . Results show that the competitive adsorption of Cu2+ and Cr(VI) is complicated, but the competitive adsorption of Cu2+ and Pb2+ is relatively simple. When Cu2+ and Pb2+ coexisted with low concentration, the competition is not obvious at entire range of pH. The competition is remarkable under high concentration at pH＜6.According to all experiment dates and analysis of theory, the modified bentonites play a great role on the wastewater treatment and environment remediation. In a word, the modified bentonites has extensive prospect on the treatment of contaminate environment.更多还原