透水路面-生物滞留池组合道路的城市面源污染控制效果评估

Evaluation of Effect of Urban Non-point Source Pollution Control on Porous Asphalt-Bio-retention Combined Roads

不同低影响开发（LID）技术组合对于控制城市面源污染具有重要应用价值,但是其对城市面源污染形成过程（污染物累积-冲刷-输送）的影响及污染负荷削减效果的评估鲜见报道.本研究以深圳市国际低碳城为例,分析了6场降雨事件下透水路面-生物滞留池组合对城市面源晴天污染物累积量、降雨径流冲刷量、不同LID设施的削减量、溢流的负荷量的影响.结果表明,研究区地表颗粒物平均累积量为（15.80±3.79）g·m^-2,粒径〉250μm的颗粒物质量占比约为65.14%;6场不同强度降雨对地表颗粒物的平均冲刷率为17.15%,粒径〈105μm的颗粒物冲刷率为62.71%-74.94%;降雨冲刷地表径流污染物SS、TN、TP的平均污染负荷分别为2.02、0.025、0.001 3 g·m^-2;透水路面下渗、过滤作用对污染物SS、TN、TP的去除率分别为70.26%、46.29%、19.27%;生物滞留池对径流二次净化去除率分别为85.25%、20.22%、70.27%;入河径流污染物SS、TN、TP的平均污染负荷分别为0.08、0.011、0.000 3 g·m^-2,是地表冲刷污染负荷的4.05%、43.47%、24.39%.透水路面-生物滞留池组合应用对道路径流中污染物的净化效果显著.通过定量化表征透水路面-生物滞留池组合应用道路的城市面源污染形成过程,以期为城市面源污染形成过程的污染负荷估算及LID工程绩效评估提供科学依据,为LID在国内的推广应用和海绵城市设计提供参考.

Different combinations of low impact development（LID） technologies can be applied for control of urban non-point source pollution. There are currently few evaluations of urban non-point source pollution and pollution load reduction based on a combination of porous asphalt and bio-retention. Taking Shenzhen International Low Carbon City as an example,road-deposited sediments were collected prior to and after rainfall events. Runoff was monitored under six typical rainfall events,from porous asphalt and the inlet/outlet of bio-retention. Through analysis of changes in the process of ＂build-up—wash-off—transport＂of pollutant loads,the average build-up of road-deposited sediments in the study area was found to be（15. 80 ± 3. 79） g·m^-2; the mass percentage of road-deposited sediments（size 250 μm） was approximately 65. 14%. The average wash-off percentage of six different intensity rainfall events was17. 15%,and road-deposited sediments（size 105 μm） were carried by 62. 71%-74. 94%. The average pollution loads of surface runoff pollutants SS,TN,and TP were 2. 02,0. 025,and 0. 001 3 g·m^-2,respectively. The removal rates of SS,TN,and TP through porous asphalt under infiltration and filtration were 70. 26%,46. 29%,and 19. 27%,respectively. The secondary purification removal rates of runoff water in bio-retention were 85. 25%,20. 22%,and 70. 27%,respectively. Pollutant loads into Dingshan River totaled0. 08,0. 011,and 0. 000 3 g·m^-2,representing 4. 05%,43. 47%,and 24. 39% of runoff. The combination thus had a significant effect on runoff purification. Through quantitative research on the formation of non-point source pollution,this paper provides a scientific basis for estimating pollution loads of urban non-point source pollution and evaluating the performance of LID projects. It makes suggestions for the popularization and application of LID and sponge city design in China.