ZHANG Huizhi (1994-), female, Master candidate. E-mail: zhz15717030682@126.com
Zeolite chabazite (CHA) membranes with a higher Si/Al mole ratio in the zeolite framework were prepared to improve their stability and separation performance. Pure zeolite CHA membranes were synthesized with imidazolium-based ionic liquids (ILs) as a structure-directing agent, which could improve the Si/Al ratio in the framework. ILs could be used repetitively at least 3 times for the synthesis of high-crystallinity zeolites. Under the optimized synthetic conditions, a continued zeolite CHA membrane obtained from an initial gel containing 1-buthyl-3-methylimidazolium bromide ([Bmim]Br) on the mullite tubular supports has a high water flux of 6.3 kg/(m2·h) with a high ion rejection (100%) for pervaporation (PV) separation of 3.5% (in mass fraction) NaCl aqueous solution at 75 ℃. The effects of temperature and feed concentration on the desalination performance of ILs-CHA membranes were also investigated. The water flux increases to 10.3 kg/(m2·h), and their salt rejections are 100% when the operating PV temperature increases at 90 ℃. Zeolite CHA membranes prepared have the superior separation performance even for desalination of 10% NaCl aqueous solution. Furthermore, the ILs-CHA zeolite membrane has a stable separation performance with a stable water flux as well as a high salt rejection in 3.5% NaCl aqueous solution at 75 ℃ for 3.5 d.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |