中空纤维膜的抗臭氧性能研究

Study on anti-ozone properties of hollow fiber membranes

针对臭氧氧化-活性炭吸附-超滤(O3-BAC-UF)集成的水处理工艺中对超滤膜的苛刻的耐臭氧性要求,对五种常用的中空纤维膜如聚偏氟乙烯(PVDF)、聚醚砜(PES)、聚丙烯腈(PAN)、聚丙烯(PP)及聚乙烯(PE)进行臭氧破坏性测试,考察了其对臭氧的耐受性;将五种膜分別在500mg/L,100mg/L,50mg/L的臭氧浓度中处理30d,并测试膜丝的纯水通量、始泡点压力、爆破压力、拉伸强力及断裂伸长率随臭氧处理时间的变化,直至膜丝发生氧化断裂.结果表明,PP、PE均在1d时间内粉化;PES则在15d后发生粉化;PAN没有发生粉化,但其水通量及机械强度下降严重;PVDF的纯水通量增加,但其机械性能几乎没有变化.相关研究可为臭氧氧化-活性炭吸附-超滤集成的水处理技术中膜的优选提供依据.

For the harsh ozone-resisting requirement of the ultrafiltration membranes applied on ozone, activated carbon adsorption and ultrafiltration （O3-BAC-UF） integrated water treatment technology, a destructive test on five typical membranes （Polyvinylidene Fluoride, Polyethersulfone, Polyacrylonitrile, Polypropylene, Polyethylene） was carried out to study their ozone tolerance. At room temperature the five membranes were treated for 30 days with ozone concentration of 50,100 and 500 mg/L respectively. And the water fluxes, bubble point and bursting pressures, tensile strengths and elongations at break were measured over time till the membranes get fractured. The results showed that PP and PE membrane powder in one day, while PES membrane in 15 days. Although no powdering phenomenon happened to PAN membrane, its pure water flux increased and its mechanical performance dropped seriously. The water flux of PVDF membrane increased significantly, but its mechanical properties change little. The study can pro- vide basis for the membrane＇s selection of O3-BAC-UF integrated water treatment technology.