季铵化改性制备荷正电纳滤膜用于锂镁分离  

Preparation of Quaternary Modified Positive Charge Nanofiltration Membrane for Li+/Mg2+Separation

作　　者：王雨[1] 付红燕 陈莹莹[1] 胡丹 冯旭东[1,2] WANG Yu;FU Hongyan;CHEN Yingying;HU Dan;FENG Xudong(School of Light Industry Science and Engineering,,Beijing Technology and Business University,Beijing 100048;Key Laboratory of Cleaner Production and Integrated Resource Utilization of China National Light Industry,Beijing 100048)

机构地区：[1]北京工商大学轻工科学与工程学院,北京100048 [2]中国轻工业清洁生产和资源综合利用重点实验室,北京100048

出　　处：《水处理技术》2025年第1期27-33,共7页Technology of Water Treatment

基　　金：北京市科学技术协会青年人才托举工程(BYESS2023180);中国食品风味与营养健康创新中心(轻工学院子平台)建设(19008023033);第二次全国污染源普查产排污核算135-137(2018-034-w-004)。

摘　　要：Mg^(2+)和Li^(+)的有效分离是从盐湖卤水中提取锂资源的主要挑战。本工作基于接枝改性的方法,先在聚合反应中引入1-(2-吡啶基)哌嗪(PDP),构筑含吡啶基团的聚酰胺复合纳滤膜,再用溴乙胺(BEA)对吡啶基团进行季铵化反应,使吡啶基团转化为季铵盐基团,得到荷正电的季铵盐类纳滤膜(TFC-PDP-BEA膜)。通过考察PDP浓度、BEA浓度、反应温度和反应时间等参数对膜结构和性能的影响,探究最佳的改性制备条件。TFC-PDP-BEA膜在最优条件下MgCl_(2)、LiCl截留率分别达到90.21%、40.78%,分离因子为6.05,水渗透通量为37.27 L/(m^(2)·h)。本工作建立了一种新的聚酰胺复合纳滤膜表面荷正电改性的方法,从而提升膜的锂镁分离性能,为纳滤膜在锂镁离子分离领域提供技术参考。The effective separation of Mg^(2+)and Li^(+)is a major challenge for the extraction of lithium resources from salt-lake brines.In this work,the surface grafting method was applied to fabricate the nanofiltration membrane,which introduced 1-(2-pyridyl)piperazine(PDP)into the interfacial polymerization reaction to construct a polyamide membrane with pyridine groups.Then quaternization reaction of bromethylamine(BEA)with the pyridine group on the membrane surface transformed the pyridine group into a quaternary ammonium group,which produced a positively charged quaternary ammonium salt nanofiltration membrane(TFC-PDP-BEA membrane).The optimal reaction conditions were investigated by examining the effects of PDP concentration,BEA concentration,reaction temperature and reaction time on the membrane structure and performance.The prepared TFC-PDP-BEA membrane showed rejections of 90.21%for MgCl_(2) and 40.78%for LiCl under the optimal conditions,with a separation factor of 6.05 and a water permeation flux of 37.27 L/(m^(2)·h).This work established a method to modify the surface of a polyamide composite nanofiltration membrane with a positive charge,and improved the lithium-magnesium separation performance,which provides a technical reference for the separation of Li+/Mg2+by nanofiltration membrane.

关 键 词：膜分离 季铵盐 盐湖提锂 取代反应 卤代烃 

分 类 号：TQ028.8[化学工程]