| Road dust is the dust deposited on road under the action of a certain momentum in the formation of dust into the environment. It is mainly from the city of bare ground, a large-scale removal of the old city, construction dust, transportation and road sweeping operations and so on. This part of the particles tend to repeatedly raised and settlement, resulting in duplication of pollution. It is seriously affecting the health of urban residents and urban ecological landscape, causing a lot of harm. Therefore, controlling of urban road dust pollution is an important way to improve air quality from the source.In this thesis, Jinan City as the study area and the city paved road dust as the research object. The physical properties of road dust are analyzed. Using USEPA's AP-42 method, combined with meteorological data and field collected survey sampling. According to AP-42 paved road dust emission factor model, road dust emission factor is calculated and the amount of road dust is estimated. Researching control technology of reducing road dust PM10, PM2.5 emissions by the laboratory simulation equipment. On this basis, in connection with urban road dust pollution characteristics and treatment status in Jinan, Studying the road dust controlling methods and means of technology.In this thesis, the laser particle size analyzer, scanning electron microscopy (SEM) analysis test tools, etc., and other experimental methods are used. The particle size distribution, specific surface area, particle density, morphology and other basic physical properties of road dust are analyzed. The results show that the test material surface area and true density were respectively 217.25m2/kg and 3.10×103kg/m3. The size distribution conforms to normal distribution and d50 is 92.20μm, as 80%of road dust particles locating in the range 6.48-220.46μm. The majority of materials of mineral particles is with irregular shape, a few very small size particles with regular shape and mostly spherical. It is the collection of dust and coal fly ash.According to AP-42 paved road dust emission factor model, road dust emission factor is calculated and the amount of road dust is estimated. The results show that road dust loading decreased with increasing traffic. Multi-city road dust loading is less than the road outside the city. As the source of road dust outside city is complex and has many factors, the road dust loading changes with time and space largely. The emission factor of spur track and secondary roads is relatively small, and the emission factor of expressway is higher. The emission factor of trunk road is the highest as its emission factor of TSP, PM10 and PM2.5 are respectively 25.2393g/VKT,4.7311g/VKT and 0.5972g/VKT respectively. Emission factor increases with the increase of average weight and it also increases with the increase of dust loading on the same type road. The dust loading influence on road dust emission factors of trunk road and expressway is relatively stable. And for spur track and secondary roads, it is relatively significant. The emission factors of secondary roads and expressway reduce with the increase of traffic volume. The traffic volume of trunk road has little influence on its emission factors. Emissions generated by a car running unit distance can be reflected by emission factors, however, because the traffic volume of different road types are vary greatly. In addition to emission factors, emissions of different road are also closely related to their traffic volume and road length. On the situation of the same road length and sampling area, the emission of road dust is larger as the emission factor is larger.Using a automatic apparatus. By the method of online spray humidification, the control technology of reducing road dust PM10,PM2.5 emission is researched. As the air pressure and water flow of atomizing nozzle are different, the rates of road dust emissions are different. The air pressure is 0.3MPa and the optimal water volume flows is 20mL/min is the best condition. Under this condition, the emission rate of the total dust of PM10,PM5 and PM2.5 are respectively 952.63mg/kg,438.71 mg/kg and 170.16 mg/kg. The reduce rate of PM10,PM5 and PM2.5 are respectively 56.07%,58.82%and 54.75%.
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