论文部分内容阅读
探讨了Mg/Al=3的水滑石焙烧产物(MgAl-LDO)对染料酸性湖蓝7(AB7)的吸附性能及其机理.考察了不同因素对MgAl-LDO吸附AB7性能的影响,并研究了吸附过程的热力学机理.实验结果表明:MgAl-LDO对AB7具有优异的吸附性能,在288 K,pH=6.74条件下,0.33 g·L-1 MgAl-LDO对150 mg·L-1AB7溶液的吸附容量和去除率分别达到446.9 mg·g-1和99.31%.热力学研究表明:MgAl-LDO对AB7的吸附过程同时符合Langmuir和Freundlich等温吸附方程,并且是个放热、自发的过程.计算所得的吉布斯自由能绝对值在8～10 kJ·mol-1,这主要是由染料分子与水滑石层板的氢键作用产生,结合Materials Studio 5.5软件模拟AB7染料分子在MgAl-LDHs上的排列分布,推测MgAl-LDO对AB7的吸附机理是表面吸附作用.同时,经4次回收,LDO对AB7的去除率仍达到85%以上.
The adsorption properties and mechanism of MgAl-LDO on the dye acid lake blue 7 (AB7) were discussed. The effects of different factors on the adsorption of ABA on MgAl-LDO were investigated. The experimental results show that MgAl-LDO has excellent adsorption capacity for AB7. The adsorption of 150 mg · L -1 AB7 solution by 0.33 g · L-1 MgAl-LDO at 288 K, pH = 6.74 The results show that the adsorption of AB7 by MgAl-LDO conforms to the Langmuir and Freundlich isothermal adsorption equations and is an exothermic and spontaneous process. The calculated results show that the adsorption capacity of ABA is up to 446.9 mg · g-1 and 99.31% The absolute value of Booth’s free energy is 8-10 kJ · mol-1, which is mainly caused by the hydrogen bonding between dye molecule and hydrotalcite laminate. Materials Studio 5.5 software is used to simulate the arrangement of AB7 dye molecules on MgAl-LDHs It is speculated that the adsorption mechanism of AB7 by MgAl-LDO is surface adsorption, meanwhile, the removal rate of AB7 by LDO still reaches over 85% after 4 times of recovery.