水电能源科学

当前，城市雨季溢流污染已成为制约城市水环境质量提升的关键因素之一。开展溢流污染溯源研究，对于揭示污染物输出规律及实现溢流污染的精准控制具有重要意义。为此，以北京市清河沿岸某典型合流制排水分区为例，针对2024年7月单次降雨过程中溢流口的溢流污水及附近区域地表径流进行了水质采样与系统监测，并采用三维荧光光谱(3D-EEM)结合平行因子分析(PARAFAC)方法，对溢流污水中溶解性有机质(DOM)的来源进行了溯源分析。结果表明，降雨初期地表径流中的污染物浓度高于溢流污水，但随着降雨的持续，地表径流污染物浓度逐渐降低并最终低于溢流污水。溢流污水中检测出三种荧光组分，分别为类富里酸组分C1、氨基酸和类腐殖质混合物混合组分C2及类酪氨酸组分C3,其占总荧光组分的比例分别为37.20%、49.29%和13.51%。溯源分析进一步表明，管道沉积物对溢流污水中DOM的贡献率最大，是其主要来源。

Currently, urban wet weather overflow pollution has become one of the key factors restricting the improvement of urban water environment quality. Conducting research on the traceability of overflow pollution is of great significance for revealing the output patterns of pollutants and achieving precise control of overflow pollution. This study systematically monitored the overflow sewage at an overflow outlet of the Qinghe River in Beijing and the surface runoff in the nearby area in July 2024. Three-dimensional excitation-emission matrix fluorescence spectroscopy(3D-EEM) combined with parallel factor analysis(PARAFAC) was employed to trace the sources of dissolved organic matter(DOM) in the overflow sewage. The results indicate that the pollutant concentration in surface runoff is higher than that in overflow sewage at the initial stage of rainfall. However, as the rainfall continues, the pollutant concentration in surface runoff gradually decreases and eventually becomes lower than that in overflow sewage. Three fluorescent components are detected in the overflow sewage, namely, the fulvic acid-like component C1, the mixed component C2 of aromatic protein-like substances and humic acid-like substances, and the tyrosine-like component C3, accounting for 37.20%, 49.29%, and 13.51% of the total fluorescent components, respectively. The traceability analysis further reveals that pipeline sediments contribute the most to the DOM in overflow sewage, representing its primary source.