低浓度NaClO和NaOH对聚偏氟乙烯超滤膜老化的影响

发布时间：2018-02-24 08:27

本文关键词： 超滤膜老化化学清洗剂膜孔径机械性能　出处：《中国环境科学》2017年02期 　论文类型：期刊论文

【摘要】：利用质量分数分别为0.2%的NaClO和0.1%的NaOH溶液老化聚偏氟乙烯(PVDF)超滤膜,研究低浓度化学清洗剂对PVDF超滤膜老化的影响.通过纯水通量、膜孔径分布、扫描电镜、拉伸性能、接触角、红外光谱和有机物截留效果,对老化后超滤膜的特征和性能进行评估.结果表明,经过NaClO和NaOH处理后,超滤膜孔径增大,对总有机碳(TOC)的截留率u636.0%分别降低至16.2%~32.4%和13.9%~24.4%.老化使PVDF膜表面发生了脱氟化氢反应,生成了C=C和C=O等新基团,改变了膜的化学组成和结构,增强了膜的疏水性.老化后膜的机械性能变差,拉断力和断裂伸长率均随老化时间的延长而降低.NaOH对PVDF膜机械性能的影响高于NaClO.
[Abstract]:The effects of low concentration chemical cleaning agent on the aging of NaClO ultrafiltration membrane were studied by using NaClO (mass fraction) of 0.2% and NaOH solution of 0.1% (0.1%), respectively. The effects of water flux, pore size distribution, scanning electron microscope, tensile properties of PVDF ultrafiltration membrane on the aging of PVDF ultrafiltration membrane were studied by means of pure water flux, pore size distribution, scanning electron microscope and tensile properties. The contact angle, infrared spectrum and organic retention effect were evaluated. The results showed that the pore size of the ultrafiltration membrane increased after NaClO and NaOH treatment. The rejection rate u636.0% of total organic carbon (TOC) was reduced to 16.2% and 13.9%, respectively. The surface of PVDF films was defluorinated by aging, resulting in the formation of new groups, such as C C and C O, which changed the chemical composition and structure of the membranes. After aging, the mechanical properties of the membrane become worse, and the tensile force and elongation at break decrease with the aging time. The effect of NaOH on the mechanical properties of PVDF membrane is higher than that of NaOH.
【作者单位】：湖南大学土木工程学院;深圳市水务(集团)有限公司;哈尔滨工业大学市政环境工程学院;
【基金】：国家水专项深圳市配套(2009ZX07423-003) 中国博士后科学基金资助项目(2016M592541)
【分类号】：TQ051.893;TU991.2

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