【摘要】 采用硅铝比（SiO₂与Al₂O₃的物质的量之比）为31.66和190.73的两种β沸石分子筛,吸附氯化1,3-二甲基咪唑（[DMIM]Cl）、氯化1-丁基-3-甲基咪唑（[BMIM]Cl）及氯化1-辛基-3-甲基咪唑（[OMIM]Cl）等3种不同分子量大小的咪唑类离子液体,研究不同硅铝比的β沸石对分子大小不同的离子液体的吸附差异.实验结果表明,β沸石对离子液体的吸附等温线符合Freundlich吸附模式,[DMIM]Cl、[BMIM]Cl和[OMIM]Cl在β₁沸石上的吸附容量分别为0.62 mmol·g^-1、0.67 mmol·g^-1和0.73 mmol·g^-1,在β₂沸石上的吸附容量分别为0.23 mmol·g^-1、0.38 mmol·g^-1和0.55 mmol·g^-1.β₁沸石的吸附效果比β₂沸石要好,且随着离子液体阳离子上烷基侧链碳原子数目增加,针对同一种吸附质,β₁和β₂沸石吸附容量之间的差异逐渐减小.吸附动力学显示[DMIM]Cl、[OMIM]Cl在β沸石上的吸附符合二级动力学,β₁沸石吸附速率高于β₂沸石,且吸附平衡所需时间更短.[DMIM]Cl和[OMIM]Cl在β₁沸石上的吸附速率常数分别为0.0248 g·mg^-1·min^-1和0.0109 g·mg^-1·min^-1,在β₂沸石上的吸附速率常数分别为0.0171 g·mg^-1·min^-1和0.0033 g·mg^-1·min^-1.β沸石对离子液体[BMIM]Cl及[OMIM]Cl的吸附容量比目前已报道文献中的活性炭的更高,是去除水体中离子液体的一种潜在优质吸附剂.更多还原

【Abstract】 In this work,we used two β zeolites with Si/Al ratios（ mole ratio of SiO₂ to Al₂O₃） of31. 66 and 190. 73 to adsorb three imidazolium-based ionic liquids, including 1, 3-Dimethyllmidazolium Chloride（ [DMIM]Cl）,1-butyl-3-methyl-imidazolium chloride（ [BMIM]Cl）and 1-octyl-3-methylimidazolium chloride（ [OMIM]Cl）,to investigate the adsorption mechanism of ionic liquid onto β zeolites. The results showed that the adsorption isotherms of ionic liquid on βzeolites were well described with the Freundlich model. The adsorption capacity of [DMIM]Cl,[BMIM]Cl and [OMIM]Cl on β₁zeolite was 0. 62 mmol·g^-1,0. 67 mmol·g^-1and 0. 73 mmol·g^-1,respectively,while the adsorption capacity on β₂zeolite was 0. 23 mmol·g^-1,0. 38 mmol·g^-1and 0. 55 mmol·g^-1,respectively. The β₁zeolite was proved to have higher adsorption capacity thanβ₂zeolite,and the difference in the adsorption capacity between β₁and β₂zeolites decreased with thenumber of the carbon atoms of the substituted alkyl chains. The adsorption process of ionic liquid over β zeolites could be well described using the pseudo-second-order kinetics,and β₁zeolite had a shorter adsorption equilibrium time than β₂zeolite. The adsorption rate constants of [DMIM]Cl and[OMIM]Cl onto β₁zeolite were 0. 0248 g·mg^-1·min- 1and 0. 0109 g·mg^-1·min- 1,respectively,and were 0. 017 g·mg^-1·min- 1and 0. 0033 g·mg^-1·min- 1onto β₂zeolite,respectively. The adsorption capacities of [BMIM]Cl and [OMIM]Cl on β zeolite are much higher than those reported on activated carbon,highlighting the potential of zeolite as promising adsorbents for the removal of ionic liquids in water.更多还原