空气隙膜蒸馏膜污染控制实验研究

EXPERIMENTAL RESEARCH ON MEMBRANE FOULING CONTROL OF AIR GAP MEMBRANE DISTILLATION

采用空气隙膜蒸馏组件,采用美国进口膜,以自来水、伞盖3号原水和苦咸水为工质,实验分析了膜污染情况,结果显示:料液无旋转时,自来水间歇累计运行32 h后出现污染;质量分数分别为20%和50%的盐水8 h后传质通量降低到最初通量32%和12%;3号原水瞬时产生污染,经砂滤处理后为苦咸水,传质通量比原水提高4倍～5倍,运行8h后通量下降到初始通量的6%。削弱膜污染方法采用最优参数的三向旋转入流组件(α=70°、δ=2 mm、β=45°),自来水进入污染期由32 h推迟到65 h,传质通量比无旋转增大近20%;采用具有分水盘的并接式空气隙膜组件,开槽2 mm膜污染较严重,开槽3 mm的膜通量比无旋转入流传质通量平均增大60%,两种组件设计形式均可提高膜通量,一定程度缓解了膜污染的产生。

Using air gap membrane distillation components,whose membrane was imported from the United States and taking tap water,raw water of No.3 canopy and brackish water as the working medium,the membrane fouling situation was analyzed by tasts.The results showed that when the working medium had no rotation,tap water appeared fouling after intermittently running for 32 h totally;the concentration of 20% and 50% of salt water mass transfer flux depressed to 32% and 12% of initial flux after 8 h;fouling appeared in the raw water of No.3 canopy instantly.After sand filter processing became brackish water,its＇ mass transfer flux raised by 4~5 times than raw water and the flux depressed to 6% of the initial flux.Reducing the membrane fouling method was the optimal three-direction revolving inflow module（α=70°,δ=2 mm,β=45°）,fouling period of tap water membrane distillation was postponed from 32 h to 65 h and the mass transfer flux was increased by 20%.Using parallel connection air gap membrane module with shunt plate,it was concluded that it was more serious fouling of 2 mm slot and the mass transfer flux of 3 mm slot was increased by 60% equally than the mass transfer flux of non-revolving membrane module.