径流污染对城市污水处理过程的DOM荧光特性影响研究

结合污水处理流程，分别采集重庆市某污水厂晴天和雨天的污水，用三维荧光光谱分析了污水中的溶解性有机物(dissolved organic matter，DOM)的荧光特性。结合DOM的DOC ( dissolved organic carbon, DOC)、COD(chemical oxygen demand, COD)、荧光指数(f_450/500)和紫外区富里酸和可见区富里酸的荧光强度比值r(A, C)的变化特征，分析了雨天径流污染对污水DOM 的影响。实验表明：该污水厂DOM的荧光指纹与典型城市生活污水有较大差异，主要成分为低激发波长类色氨酸(Peak S), 长激发波长类色氨酸(Peak T)次之;A2/O工艺对雨天和晴天的类蛋白物质的去除效果相当，但是雨天的类富里酸以及DOC和COD的去除率较晴天高, 经过生化处理后的荧光峰均发生细微的红移;晴天和雨天污水的DOM 荧光指纹差异明显，雨天紫外富里酸(Peak A)荧光中心由晴天的240～248/390～440 nm蓝移到240～250/370～400 nm。虽然晴天和雨天的DOM种类相同，但是雨水径流使富里酸的来源复杂，组分比例发生了较大变化，雨天色氨酸(Peak S)的比例下降了10%，紫外富里酸(Peak A)的比例上升7%。

The Influence of Runoff Pollution to DOM Features in an Urban Wastewater Treatment Plant

Combined with wastewater treatment process, the sewage in sunny and rainy day was collected from a wastewater treatment plant in Chongqing. Three-dimensional fluorescence spectra was used to investigate the characteristic fluorescence of dissolved organic matter (DOM). DOM dissolved organic carbon (DOC), chemical oxygen demand (COD), fluorescence index (f_450/500) and fluorescence intensity ratio r(A, C) of fulvic acid in ultraviolet and visible region wereused to analyze the impact of rain runoff pollution on sewage DOM. According tothe experimental data，the DOM fluorescence fingerprints of this wastewater treatment plant were quite different from typical municipal sewage, and the main component was tryptophan with low excitation wavelength (Peak S), then the tryptophan with long wavelength excitation (Peak T) followed. A2/O process had an approximative degradation of the protein-like both in sunny day and rainy day, but had a better degradation of fulvic-like, DOC and COD in rainy day thanthat in sunny day. Morever, the fluorescence peaks got red-shifted after the biological treatment. The differences of DOM fluorescence fingerprint between sunny and rainy day were significant, the fluorescence center of UV fulvic (Peak A) in rainy day getting blue-shifted obviously, shifting from 240～248/390～440 to 240～250/370～400 nm. Although the DOM types in sunny and rainy day were the same, the source of fulvic got more complex by runoff and the component ratioof DOM also changed. Compared with the sunny day, the proportion of Peak S in DOM dereased by 10%, and the proportion of Peak A increased by 7% in rainy day.