纳滤膜技术在地下水除砷应用中的研究进展

Investigation progress of arsenic removal from groundwater by nanofiltration membrane technology

砷污染突发事件的频发严重威胁着地下水饮用水水源的水质安全,加之饮用水控制标准的提高,就对饮用水除砷技术提出了更高的要求,而纳滤(NF)膜分离技术为饮用水除砷提供了新的思路。首先概述了地下水中砷的存在形态、化学性质以及我国高砷地下水地区分布,然后分析了NF膜特点、除砷机理与性能,系统地阐述了各种因素包括膜操作因素(操作压力、膜回收率、膜排布方式等)和原水水质因素(pH、水温、共存离子、共存有机物及砷浓度与砷价态等),对NF膜除砷性能的影响。此外,对NF除砷的关键问题,如原水预处理、膜浓水处理、膜污染及其清洗等,也作了探讨。最后,总结了目前NF除砷应用中所面临的问题,探索性提出了NF膜技术在除砷应用中的研究方向。

The frequent emergencies of arsenic pollution seriously threatening the water quality and safety of underground drinking water sources,coupling with the improvement of controlling standards for drinking water,have put forward higher requirements for the arsenic removal from drinking water.However,nanofiltration（NF） membrane separation technology provides a new method for arsenic removal.Firstly,the arsenic existing conformation in groundwater,its chemical properties and distributions in groundwater of China were overviewed.Then,NF membrane characteristics and its performances of arsenic removal mechanism were analyzed.The influences by the various factors,including membrane operating factors（operating pressure,recovery rate,the membrane arrangement,etc.） and raw water quality factors（pH,temperature,coexisting ions,organic compounds,arsenic concentration and the valence states of arsenic,etc.）,on NF membrane performance,were systematically exposited.In addition,some key issues for arsenic removal by NF,such as raw water pretreatment,membrane concentrated water disposal,and membrane fouling/cleaning,were also discussed.Finally,the current problems of NF application for arsenic removal were summarized,and application research aspects of NF membrane technology for arsenic removal were tentatively proposed.