离子液体负载型碳纳米管吸附除砷研究

Removal performance of arsenic by carbon nanotube adsorbents loaded with ionic liquid

通过浸渍法制备4种离子液体负载型碳纳米管吸附材料,分别采用静态法和动态法考察其对溶液中As(Ⅲ)和As(Ⅴ)的去除性能。研究结果表明:负载离子液体的碳纳米管对As(Ⅲ)和As(Ⅴ)具有较强的吸附作用,吸附过程属于单分子层的化学吸附,吸附行为符合Langmiur吸附;Im-CNT,tBu-CNT,Nme-CNT和Nmb-CNT这4种吸附材料对As(Ⅲ)的去除效果优于对As(Ⅴ)的去除效果;负载氮氧杂冠醚型离子液体的碳纳米管对砷的去除效果比负载咪唑型离子液体的碳纳米管的去除效果更优,说明冠醚型离子液体的空腔结构对砷具有良好的配合性能,同时,冠醚结构中取代烃基的长度对砷的去除也有一定的影响。

The removal efficiencies of arsenic from solution by ionic liquids loaded carbon nanotubes （ILs/CNT） composite adsorption material was investigated by static and dynamic adsorption experiments respectively. The results show that carbon nanotubes loaded with ionic liquid have a strong adsorption effect on As（III） and As（V）, which belongs to single-layer chemical adsorption and can be described by Langmiur formula. The removal efficiency of As（III） with four adsorbents i.e., Im-CNT, tBu-CNT, Nme-CNT and Nmb-CNT, is better than that of As（V）. The arsenic removal efficiency of carbon nanotubes loaded with monoazacrown ether type ionic liquids is superior to that carbon nanotubes loaded with imidazole type ionic liquids, which shows that the crown ether structure has a good coalescent performance with arsenic, meanwhile the length of alkyl in monoazacrown ether ionic liquids has a certain impact on arsenic removal.