高选择性纳滤分离技术助力高盐环境中资源提取与回收

HIGHLY SELECTIVE NANOFILTRATION SEPARATION TECHNOLOGY FACILITATES RESOURCE EXTRACTION AND RECOVERY FROM HIGH SALINITY ENVIRONMENTS

在低碳目标和循环经济框架下,资源回收与提取得到广泛关注。高盐废水中蕴藏着丰富的资源,直接排放会造成环境污染和资源浪费。围绕纳滤膜在高盐环境中资源回收与提取的应用前景,梳理了近年来离子选择性纳滤技术的发展趋势。总结了纳滤膜空间位阻效应、道南效应、介电排斥效应和溶质脱水合及溶质-膜材料弱相互作用等对溶质分离的作用机理,论述了纳滤技术的分离因子、纯度、回收率和渗透率等评价指标的意义及其对纳滤膜性能的要求。此外,选取了海水资源提取、工业废水零排放、盐湖提锂和电镀废水处理4种具有代表性的高盐环境,介绍了目前纳滤膜的应用现状和发展方向。最后,从资源回收的角度,以回收率和纯度作为标准,分析了水渗透性和分离选择性的优化方法,为面向高盐环境资源提取的高选择性纳滤膜定制设计提供建议。

Within the ambit of low-carbon objectives and the circular economy paradigm,resource recovery and extraction have received wide attention.High-salinity wastewater,as a trove of untapped resources,poses a dual challenge:the direct emissions of high salinity wastewater lead to environmental pollution,and squander valuable resources.This review delves into the application of nanofiltration(NF)membranes in resource recovery and extraction from high salinity environments,meticulously tracing the recent advancements in ion-selective NF separation technologies.Firstly,we consolidate the solute separation mechanisms of NF membranes,encompassing steric effect,Donnan exclusion,dielectric exclusion effects,and transition state theory.Subsequently,we delve into the evaluation metrics essential for assessing NF membrane performance,including separation factor,purity,recovery rate,and solute permeability.Furthermore,we highlight four exemplary high-salinity scenarios,seawater resource extraction,zero discharge of industrial wastewater,lithium extraction from brines,and electroplating wastewater treatment,where NF membranes have demonstrated promising applications and ongoing developments.These cases illustrate the versatility and potential of NF technologies in addressing diverse resource recovery challenges.Lastly,from a resource recovery perspective,we dissect optimization strategies aiming at enhancing water permeability and separation selectivity.These insights offer valuable guidance for the customization of highly selective NF membranes,tailoring them to meet the unique demands of various high-salinity environments.This review contributes to advancing the frontier of NF membrane technology and fostering sustainable resource management practices.