典型街谷行人高度大气污染物空间浓度特征试验研究

Experimental Investigation on Spatial Concentration Characteristics of Air Pollutants at the Height of Pedestrians in a Typical Street Canyon

人居环境中的空气质量与人们的生活息息相关。街谷作为现代城市建设中重要的构成部分,空气污染对长期暴露其中的居民健康带来了巨大影响。采用便携式空气污染物监测设备以走停交替的移动方式测量分析了典型街谷内行人高度处常见大气污染物(SO_(2)、CO、NO_(2)、O_(3)、PM_(2.5)、PM_(10))的空间浓度特征。研究表明,常见污染物的测量方法所需响应时间具有明显差异性,排序为:O_(3)>NO_(2)>SO_(2)>PM_(10)>PM_(2.5)>CO,需根据响应时间合理规划测点停留时间;街谷内大气污染物浓度主要受建筑布局、污染物自身生成机理以及与污染源距离的影响。街谷内建筑布局越密,污染物不易扩散,其浓度越高;距离污染源越远,污染物的浓度越低。

Air quality is closely related to individuals’lives.Air pollution dramatically influences the health of residents chronically exposed in street canyons which play a significant role in modern urban construction.Based on a“stop-and-go”strategy,we conducted a mobile measurement by a portable air pollution monitoring equipment to analyze the spatial concentration of air pollutants(SO_(2),CO,NO_(2),O_(3),PM_(2.5),PM_(10))at the height of pedestrians in a typical street canyon.The results showed that the common pollutants differ obviously in the response time of measurement,as follows:O_(3)>NO_(2)>SO_(2)>PM_(10)>PM_(2.5)>CO.So,staying time on each measuring point should be determined based on the response time.The concentration of air pollutants in the street valley is mainly affected by the layout of buildings,the generation mechanism of pollutants,and the distance from the pollution source.The denser the layout,the less the pollutant dispersion,and the higher the concentration.The farther away from the pollution source,the lower the concentration.