不同氧化剂降低膜污染效果的研究

采用不同的氧化剂预处理黄浦江原水后进行微滤膜(MF)膜过滤试验,考察预氧化对有机物的去除作用,及其对MF膜过滤特性的影响.结果表明,3种不同氧化剂对有机物的去除效果存在较大差别.臭氧投量在0.5~3.0mg/L范围内,臭氧对DOC和UV254的去除率最高分别为10%和71%;而氯和高锰酸钾对有机物的去除效果则较差.臭氧可将大分子有机物转变成小分子有机物,将大部分疏水性有机物氧化成亲水性有机物.这种有机物组成结构的改变对膜过滤特性产生影响,明显降低了膜污染,膜污染下降率最高可达到22.7%.氯和高锰酸钾的氧化性相对较弱,仅能去除少部分疏水性有机物,对膜污染有较小减缓作用,膜污染下降率最高分别为9%和8.5%.

Comparison of different oxidants reducing membrane fouling

In order to investigate the effect of different preoxidation processes on organic matter and microfiltration (MF) membrane filtration, oxidized surface water from Huangpu River was filtrated by MF membrane. There was a significant difference among organic matter degradation by ozone, chlorine and potassium permanganate. Highest removal of DOC and UV254 of 10% and 71% were observed in ozone oxidation process with dosage in range of 0.5~3.0mg/L. Compared with ozone, removal of organic matter by chlorine and potassium permanganate were poor. Ozone could degrade high molecular matters to low molecules, and transfered hydrophobic organic to hydrophilic ones. Chemical structure alternation of organic matters greatly affected membrane filtration with membrane fouling reduced obviously, and highest value of membrane fouling reduction reached 22.7%. Chlorine and potassium permanganate only removed hydrophobic fraction slightly due to their low oxidation, thereby subdued little membrane fouling, highest value of membrane fouling reduction were 9% and 8.5%, respectively.