陶瓷膜污染过程分析与膜清洗方法优化

Analysis on ceramic membrane fouling procedure and optimization of membrane flushing method

采用膜孔径为50 nm的陶瓷膜错流过滤方式,对碱性高浓度有机洗涤废水进行9个周期的膜通量衰减及反向脉冲清洗再生实验研究。通过设计膜污染阻力构成实验,测算膜污染总阻力及其构成比例。实验结果表明,膜固有阻力比例较低,浓差极化污染较弱,Rt和Rc+Rirf污染阻力稳定性较高,膜堵塞形式兼有孔内堵塞和滤饼过滤;选择质量分数0.1%的稀盐酸和0.2%的草酸溶液膜清洗效果均较好,清洗时间为3 min,脉冲时间和频率为3 s/5 s。

The alkaline organic washing wastewater of high concentrations was treated by cross-flow filtra- tion of ceramic membrane with a pore size of 50 nm. The decline regularity of membrane flux was studied and re- generating the fouled membrane with reverse pulse flushing was carried out in 9 running cycles. Then the total resistance of the membrane fouling and its composition were calculated. The results showed that the proportions of membrane intrinsic resistance and concentration polarization pollution were lower compared to others. The membrane fouling resistances of Rt, Re plus Rirf were higher and remained stable during every cycle. Moreover, the membrane was both blocked in the forms of pore blocking and cake layer filtration. Finally, the cleaning of membrane fouling was conducted with the pulse duration and frequency of 3 s/5 s for 3 rain by 0.1% of HCl or 0.2% of oxalic acid. The membrane fouling could be removed effectively.