臭氧预氧化对混凝-超滤处理微污染水的影响

Effect of Pre-Ozonation on the Performance of Coagulation-Ultrafiltration Combined Process for Micro-Polluted Water Treatment

针对我国饮用水水源微污染日益严重的现状,从出水水质改善和膜污染控制两方面考察了臭氧预氧化对"混凝-超滤"工艺运行效果的影响,并通过对溶解性天然有机物三维荧光光谱和分子质量分布特征的分析探讨了臭氧氧化对溶解性有机物的降解规律.结果表明,微污染原水中大分子腐殖质类物质对于臭氧预氧化比较敏感,所含的芳环结构会被破坏,生成小分子亲水性有机物.这一转变不仅能够降低"混凝-超滤"出水中有机物质量浓度,而且能够限制有机物在膜表面的累积,减缓膜污染的发展.臭氧质量浓度是臭氧预氧化的关键参数,过高的臭氧浓度会加剧颗粒态有机物向溶解性有机物的转化,这对于膜污染控制有不利影响.

Micro-pollution of surface water threatens drinking water safety, which has become an increasingly serious issue. The effect of pre-ozonation on the performance of coagulation-ultrafiltration combined process was investigated in terms of effluent quality and membrane fouling in this study. The degradation of natural organic matters via pre-ozonation was discussed based on the 3D excitation-emission matrix fluorescence spectrum and molecular weight distribution analysis. Results show that humus with large molecular weight in raw water is sensitive to pre-ozonation. Structure with aromatic rings is decomposed into smaller hydrophilic species. This transition decreases the organic matter concentration in the effluent and alleviates the aggregation on the membrane surface as well as themembrane fouling development. Ozone mass concentration is a key operation parameter. Overhigh mass concentra-tion of ozone intensifies the dissolution of organic particles and worsens membrane fouling.