Fe_(3)O_(4)/MWCNT改性纳滤膜对Mg^(2+)/Li^(+)的分离性能  

Performance of Fe_(3)O_(4)/MWCNT Modified Nanofiltration Membranes for Separation of Mg^(2+) and Li

作　　者：陈亦洁 王琎 孟晓荣[1,2] CHEN Yi-jie;WANG Jin;MENG Xiao-rong(School of Chemistry and Chemical Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,China;Key Laboratory of Membrane Separation of Shaanxi Province,Shaanxi Membrane Separation Technology Research Institute,Xi’an 710055,China)

机构地区：[1]西安建筑科技大学化学与化工学院,陕西西安710055 [2]陕西省膜技术分离研究院陕西省膜分离重点实验室,陕西西安710055

出　　处：《中国给水排水》2024年第21期81-86,共6页China Water & Wastewater

摘　　要：目前从高镁锂比盐湖卤水提取和分离锂相当困难,为提升Mg^(2+)和Li^(+)的分离效率,将四氧化三铁包覆的多壁碳纳米管(Fe_(3)O_(4)/MWCNT)掺入超滤(UF)基膜中来优化荷正电纳滤(NF)膜的性能,研究了在磁场诱导条件下Fe_(3)O_(4)/MWCNT掺杂对UF膜和NF膜形貌结构和表面性能的影响。磁场诱导Fe_(3)O_(4)/MWCNT纳米粒子迁移到膜表面,最终落于UF基膜与聚酰胺层之间,提升纳滤膜渗透通量的同时提高了膜的荷正电性。当Fe_(3)O_(4)/MWCNT掺杂量为0.5%(质量分数)时,改性NF膜对Mg^(2+)和Li^(+)显示出较高的选择分离性能,分离因子从纯复合NF膜的2.15提升至4.20,水通量提升至49.4 L/(m^(2)·h·MPa)。Currently,it is extremely challenging to extract and separate lithium from salt lake brine with a high Mg^(2+)/Li^(+)ratio.To enhance the separation efficiency of Mg^(2+)and Li^(+),ferroferric oxide coated multi-walled carbon nanotube(Fe_(3)O_(4)/MWCNT)were integrated into the ultrafiltration(UF)based membrane to optimize the performance of the positive electrical nanofiltration(NF)membrane.The influences of Fe_(3)O_(4)/MWCNT doping on the morphology,structure,and surface properties of UF and NF membranes under magnetic field induction were examined.The Fe_(3)O_(4)/MWCNT nanoparticles were induced by magnetic field to migrate towards the surface of the membrane and eventually dropped between the UF membrane and the polyamide layer.As the osmotic flux of the nanofiltration membrane was enhanced,the positive charge of the NF membrane was likewise augmented.When the doping content of Fe_(3)O_(4)/MWCNT was 0.5%(mass fraction),the modified NF membrane demonstrated a higher selective separation performance for Mg^(2+)and Li^(+),with the separation factor increasing from 2.15 to 4.20 and the water flux rising to 49.4 L/(m^(2)·h·MPa).

关 键 词：镁锂分离 荷正电纳滤膜 四氧化三铁 多壁碳纳米管 改性 

分 类 号：TU992[建筑科学—市政工程]