臭氧氧化对陶瓷膜超滤工艺降低饮用水中浊度的影响

Effects of ozonation on removal of turbidity in drinking water using ceramic membrane ultrafiltration

利用臭氧陶瓷膜超滤集成工艺,研究了臭氧对陶瓷膜超滤工艺处理不同浊度原水的影响.实验用陶瓷膜平均孔径为100nm.结果表明,与不投加臭氧的情况相比,投加3mg·L-1臭氧可将浊度为14、52、108和510NTU原水的膜通量提高18.2%～104.9%,投加5mg·L-1臭氧可将此值提高至21.7%～116.3%,而投加1～2mg·L-1臭氧对膜通量的改善不明显.投加5mg·L-1臭氧可将CODMn的去除率提高至28.7%～46.9%,投加1～3mg·L-1臭氧对CODMn的去除率无显著影响,膜出水有机物浓度有所升高.臭氧氧化后原水中小分子量有机物增多,降低了膜的有机物污染程度,有利于膜通量改善.集成工艺出水中2～3μm颗粒物数量为10～36个·mL-1.臭氧氧化导致陶瓷膜过滤初期出水中颗粒物数量略微升高.本研究对于水中颗粒物通过陶瓷超滤膜孔的探讨,以及改善膜对颗粒物的去除具有重要的指导意义.

The effect of ozone on the performance of a hybrid ozone-ceramic membrane ultrafiltration was investigated using raw water with different turbidities. Average pore size of ceramic membrane tested was 100 nm. Ozonation with 3 mg·L^-1 ozone increased the membrane fluxes by 18.2%～104.9% with raw water turbidities ranging from 14 to 510 NTU. The percentages increased to 21.7%～116.3% for 5 mg·L^-1 ozone. There was no significant effect on the membrane flux for the ozone dosage of 1 to 2 mg·L^-1. Ozonation with 5 mg·L^-1 dosage removed 28.7%～46.9% organics in terms of CODMn. While 1～3 mg·L^-1 ozone did not remove CODMn significantly, its concentrations increased slightly in membrane effluent. Ozonation converted the organics into smaller molecular weight, which decreased the membrane fouling, and improved the membrane flux. The 2～3 μm particle counts in the effluent of the hybrid process were 10～36 cnt·mL^-1. Ozonation may result in slight increase of particle count in the membrane effluent. Exploration of particulate matter breaking through membrane pore in this paper is of practical importance for the improvement of particle removal in membrane ultrafiltration.