Key Laboratory of Urban Stormwater System and Water Environment, Ministry of Education, Beijing University of Civil Engineering and Architecture, Beijing, 100044, China.
Beijing Engineering Research Center of Sustainable Urban Sewage System Construction and Risk Control, Beijing University of Civil Engineering and Architecture, Beijing, 100044, China.
Environ Sci Pollut Res Int. 2021 Apr;28(16):20082-20092. doi: 10.1007/s11356-020-12020-3. Epub 2021 Jan 6.
The characteristics of colloids in urban road runoff with different traffic in Beijing, China, such as concentration, particle size, chemical property, and affinity for heavy metals were determined. The concentration of colloids was high, and an evident first flush effect was found in the runoff of road with heavy traffic. A large portion of colloids were distributed in the range of 1-10 μm. Traffic activity, rainfall intensity, and time of sample collection would not change the size distribution of colloids in the road runoff. The chemical property of colloids in the road runoff would be influenced by the soil erosion nearby green space, causing the content of organic colloids was high. The correlation coefficient between the concentration of colloids in colloidal fractions and the concentration of heavy metals (Cu, Zn, Cd, Pb, Fe, and Mn) in the road runoff with different traffic decreased with the same sequence from 0.02-0.2 μm, 0.2-0.45 μm, 0.45-1 μm, to 1-10 μm, suggesting that the heavy metals had stronger affinity for the colloids with small size. The concentration of Cu, Pb, and Zn exhibited significant correlations with the concentration of organic colloids in the road runoff. More aggregated spherical particles were found in the TEM image of the road runoff with heavy traffic. Zeta potentials and RMV data showed that the colloids with smaller size and the colloids in the road runoff with lighter traffic were much more stable.
研究了中国北京不同交通条件下城市道路径流中胶体的特性，如浓度、粒径、化学性质和重金属亲和力等。结果表明，胶体浓度较高，重交通道路径流中存在明显的初期冲刷效应。大部分胶体分布在 1-10μm 的范围内。交通活动、降雨强度和采样时间不会改变道路径流中胶体的粒径分布。附近绿地的土壤侵蚀会影响道路径流中胶体的化学性质，导致有机胶体含量较高。不同交通条件下道路径流中胶体颗粒和重金属（Cu、Zn、Cd、Pb、Fe 和 Mn）浓度之间的相关系数，随着粒径的减小，依次从 0.02-0.2μm、0.2-0.45μm、0.45-1μm 和 1-10μm 减小，表明重金属与小粒径胶体的亲和力更强。Cu、Pb 和 Zn 的浓度与道路径流中有机胶体的浓度呈显著相关。在重交通条件下的道路径流 TEM 图像中发现了更多的团聚球形颗粒。zeta 电位和 RMV 数据表明，粒径较小的胶体和交通流量较轻的道路径流中的胶体稳定性更高。
