【作者】 郭丹丹；

【导师】 彭书传；

【作者基本信息】 合肥工业大学 ， 环境工程， 2009， 硕士

【摘要】 本文用十六烷基三甲基溴化铵(CTAB)改性凹凸棒石,制备了不同负载量的有机改性凹凸棒石,对比研究了不同负载量的有机改性凹凸棒石对4-氯苯酚吸附能力;通过三种方式研究有机改性凹凸棒石对4-氯苯酚溶液的吸附;通过吸附热力学和动力学实验探讨了有机改性凹凸棒石对4-氯苯酚溶液吸附机理。结果表明:三种不同方式的吸附研究中,第三种方式的吸附效果最好;有机改性凹凸棒石对4-氯苯酚溶液的吸附平衡数据能够较好得符合Freundlich吸附等温方程。对4-氯苯酚的吸附焓变为-11.55kJ/mol,是一个放热过程。对4-氯苯酚吸附自由能为负值,是常温常压下可以自发的过程,是物理和化学吸附并存的过程,并且是熵增过程。有机改性凹凸棒石对4-氯苯酚溶液的吸附能够较好地符合准二级动力学方程;表观活化能为19.24kJ/mol,表明此吸附并不是单一的以化学吸附为速率控制步骤,同时也存在一个以液膜扩散为速率控制步骤,是由液膜扩散和化学吸附共同控制的过程。发现有机改性凹凸棒石对4-氯苯酚溶液的吸附性能与表面活性剂载量呈正相关,有机改性凹凸棒石的吸附性能随着表面活性剂负载的增加而呈现出先增加后减小的变化趋势。更多还原

【Abstract】 The cetyltrimethyl ammonium bromide (CTAB) is used to prepare organic modified palygorskites at different capacities. The contrast of adsorptive capacity of them to 4-chlorophenols has been studied. In three ways, the adsorption experiments by organic modified palygorskite to 4-chlorophenols are carried out. And the adsorption mechanism is studied through the experiments of adsorption thermodynamics and dynamics. The results are presented as follows:In the adsorption study, result of the third way has proved to be better. The adsorption results by organic modified palygorskite to 4-chlorophenol can fit well to the Freundlich adsorption equation through isothermal adsorption data. The adsorption enthalpy is 11.55kJ/mol, so the reation is proved to be an exothermic process. While the adsorption free energy is negative, the adsorption is a spontaneous process under the normal atmospheric pressure and at room temperature. Furthermore, through the thermodynamics and dynamics experiments, the process has been proved to be a coexist reaction, which contains both physical and the chemical adsorptions. It can also be found that the entropy increases in the process. The second order dynamic equation is applied to adsorption of 4- chlorophenol by organic modified palygorskite as well, and then the experimental data are proved to fit well into the form. The apparent adsorption active energy is 19.24kJ/mol. This relatively low apparent adsorption activation energy suggests that the adsorption of organic modified palygorskite may be involved in not only chemical but also physicial adsportion process, which is likely attributed to its combined control of chemical adsorption and film diffusion. Finally it is discovered that the adsorption capacity is related to the loaded capacity of used surfactant. The adsorption capacity increases at first, then reduces when the loaded capacity of surfactant increases.更多还原