State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, People's Republic of China.
Key Laboratory of Urban Stormwater System and Water Environment, Beijing University of Civil Engineering and Architecture, Beijing, 100044, People's Republic of China.
Environ Sci Pollut Res Int. 2016 Feb;23(3):2693-704. doi: 10.1007/s11356-015-5512-5. Epub 2015 Oct 6.
The deposition of pollutants on impervious surfaces is a serious problem associated with rapid urbanization, which results in non-point-source pollution. Characterizing the build-up and wash-off processes of pollutants in urban catchments is essential for urban planners. In this paper, the spatial variation and particle-size distributions of five heavy metals and two nutrients in surface dust were analyzed, and the runoff water first-flush effect (FF30) and event-mean concentrations (EMCs) of 10 common constituents were characterized. The relationships between runoff variables and stormwater characteristics were examined from three typical urban impervious surfaces in Beijing, China. Dust on road surfaces with smaller grain sizes had higher pollutant concentrations, whereas concentrations of Mn, Zn, Fe, and TP in roof surface dust increased with grain size. Particles with grain sizes of 38-74 and 125-300 μm contributed most to the total pollutant load in roads, while particles with the smallest grain sizes (<38 μm) contributed most on roofs (23.46-41.71 %). Event-mean concentrations (EMCs) and FF30 values for most runoff pollutants tended to be higher on roofs than on roads. The maximum intensity (I max) and the antecedent dry days (ADD) were critical parameters for EMCs in roads, while ADD was the only dominant parameter for EMCs on our studied roof. The rainfall intensity (RI) and maximum intensity (I max) were found to be the parameters with the strongest correlation to the first-flush effect on both roads and roofs. Significant correlations of total suspended solids (TSS) concentration in runoff with grain-size fractions of surface dust indicated that coarser particles (74-300 μm) are most likely to contribute to the solid-phase pollutants, and finer particles (<38 μm) are likely the main source of dissolved pollutants.
不透水面上的污染物沉积是与快速城市化相关的一个严重问题，这会导致非点源污染。描述城市集水区中污染物的积累和冲刷过程对于城市规划者至关重要。本文分析了表面灰尘中 5 种重金属和 2 种养分的空间变化和粒度分布，并对 10 种常见成分的径流水初次冲刷效应（FF30）和事件平均浓度（EMCs）进行了特征描述。从中国北京的 3 种典型城市不透水面，研究了径流水变量与雨水特征之间的关系。粒径较小的路面灰尘中污染物浓度更高，而屋顶表面灰尘中的 Mn、Zn、Fe 和 TP 浓度则随粒径增大而增加。粒径为 38-74μm 和 125-300μm 的颗粒对道路总污染物负荷的贡献最大，而粒径最小的颗粒（<38μm）对屋顶的贡献最大（23.46-41.71%）。大多数径流水污染物的事件平均浓度（EMCs）和 FF30 值在屋顶上均高于在道路上。对于道路，最大强度（I max）和前期干燥天数（ADD）是 EMCs 的关键参数，而对于研究的屋顶，ADD 是唯一的主导参数。发现降雨强度（RI）和最大强度（I max）是道路和屋顶初次冲刷效应的最强相关参数。径流水中总悬浮固体（TSS）浓度与表面灰尘粒度分数的显著相关性表明，较粗颗粒（74-300μm）最有可能导致固相污染物，而较细颗粒（<38μm）则可能是溶解态污染物的主要来源。
