再生水中色度物质的识别及其臭氧去除特性

针对我国再生水普遍存在的色度问题,以天津市某污水厂二级出水为研究对象,采用三维荧光光谱和GC/MS技术对其进行组成分析,结果表明:再生水中主要带色物质为富里酸与腐殖酸类物质,同时还存在偶氮二甲酸二乙酯、N,N-二甲基乙醇胺、苄醚、1,4-二甲基吡啶氯化物等导致再生水色度的带色有机物。在再生水的臭氧降解实验中,臭氧可有效降解再生水中的富里酸与腐植酸类物质,去除率分别达到96.5%、97.3%。臭氧对再生水的色度与CDOM(有色溶解有机物)的降解也表现出了良好的效果,2 min内去除率可分别达到93.1%、86.2%。并且在色度物质的臭氧降解过程中,臭氧的直接反应占据主导地位,而并非与·OH的间接反应。该结果对再生水臭氧氧化工艺的设计应用有现实的指导意义。

THE RECOGNITION OF COLOR MATERIALS IN THE RECLAIMED WATER AND ITS REMOVAL CHARACTERISTIC BY OZONE DEGRADATION

For the widespread problem on color of the reclaimed water in China,the three-dimensional excitation-emission matrix fluorescence spectrum and GC/MS technique were used to analysis the composition of the color materials in the secondary effluent of wastewater treatment plants in Tianjin.The results indicated that the main color materials in the reclaimed water were fulvic acid and humic acid.Meanwhile,diethyl azodicarboxylate N,N-dimethylaminoethanol benzyl ether and 1,4-dimethyl-pyridinium chloride also contributed to color degree of the reclaimed water.The results of ozone degradation experiment showed that the fulvic acid and humic acid substance in the reclaimed water could be degraded by ozone effectively,with the removal rate of 96.5％ and 97.3％,respectively.The color of the reclaimed water and the concentration of CDOM (chromophoric dissolved organic matter) were also removed by ozone effectively,in the first two minutes,the removal rate could reach 93.1％ and 86.2％,respectively.Furthermore,the direct reaction of the ozone degradation process played the most important role in the degradation process of color materials,rather than the reaction of hydroxyl free radical (· OH).This conclusion could be of guiding significance to the application of ozonation process for reclaimed water decoloration.