道路交通扬尘排放因子测量系统研发及应用

道路交通扬尘排放是城市大气环境颗粒物(PM_(10)和PM_(2.5))的主要来源之一,对其排放测量研究是进行排放清单建立、环境影响分析和制定控制方案的依据.本研究设计了一种道路交通扬尘排放因子测量系统,通过测量行驶中车辆尾羽不同位置的颗粒物浓度,应用浓度剖面积分的方法计算单车行驶过程中扬尘PM_(10)排放量.在北京市典型道路测量了小汽车和大客车在不同车速下的交通扬尘颗粒物排放因子,结果显示,车辆尾羽的颗粒物浓度特征呈明显的"层状"分布,距离路面越近浓度越高,在车辆行驶方向中心浓度最高,向两侧浓度逐渐降低,车速越快浓度越高.在试验车速范围内,排放因子与车速呈幂函数关系,幂指数为2.7~2.8.排放因子与积尘负荷呈幂函数关系,幂指数为0.85.不同路段或同一路段的不同区域排放因子空间变异性较大,应用排放因子测量系统进行实测的结果更加准确可靠.

Development and application of an emission factor measurement system for road fugitive dust

Road fugitive dust emission (PM₁₀ and PM_2.5) is one of the major sources of airborne particulate matter pollution in urban areas,and the study of road fugitive dust emission is the basis of emission inventory establishment,environmental impact analysis and control measures making. In this paper,a road fugitive dust emission factor measurement system was developed. By measuring the concentrations of particulate matter in different positions of vehicle''s wake and using concentration profile integral method,fugitive dust emission of single vehicle was calculated and emission factors of personal automobiles and public buses were measured under different driving speeds. Results showed that concentrations of particulate matter from vehicle''s wake appeared an obvious layered distribution. Concentrations were higher closer to the ground and with higher speed. Higher concentrations were also observed in the middle of the road than the road sides. In the given speed range,emission factor showed a power function relationship with speed,and the power exponent values fell in the range of 2.7 to 2.8. Emission factors also indicated a power function relationship with silt loading with a power exponent of 0.85. As emission factors showed a large variability,the values determined by this measurement system were more accurate and reliable.