澳门机动车排放污染特征及控制策略研究

The vehicle population density in Macao is one of highest in the world, about 4700 vehicles km-2 in 1999, and most of vehicles running in Macao Peninsular. Vehicle emissions got more and more concern from the public in recent years. It was important to get knowledge of vehicle emission characteristics and then design control strategies in Macao. In this study the researchers were committed to clarify the characteristics of atmospheric pollutants, vehicle emission characteristics and their effects on air quality and propose feasible strategies to control vehicle emissions in Macao. By the meanings of field survey, in-situ and laboratory experiments and numerical simulation and modeling, it has been acquired detail knowledge on air quality, chemical characteristics of airborne particulate matters, vehicle emission characteristics and rules of air pollutant dispersion. Furthermore, emission inventory of Macao has been developed with the contribution of different sources determined and it was given different control scenarios with analysis of their effects on emission reduction and air quality improvement. By the research, it indicated that there was no sharp decline or improvement of the air quality in Macao since 1991. The particle pollution in central business district was severe and much higher than the average level. Roadside concentration of NO2 in busy traffic area was much higher than ambient concentration, with a little nonattainment. The chemical analysis of airborne particulate matters indicated 36 elements, water-soluble ions, and carbonaceous species were present. The greatest contributors to total PM10 and PM2.5 mass were OC, sulfate, nitrate, ammonium, EC, Na, Cl, and crustal elements including Si, Ca, Al, Fe, K, and Mg. Organic material was the largest single fraction of airborne particulate matter in Macao. The research on VOCs in "street canyon" area in Macao showed that even in summer with best air quality the exposure levels of benzene and other monocyclic aromatic hydrocarbons might be much higher compared to the guideline levels or limits suggested by some studies or regulatory bodies. Principal component analysis using major hydrocarbon species indicated that traffic related emissions could explain 78% of the data variance of the samples, and evaporated and transported species might be sources of much less important. The emission tests indicated that the emissions of carburetor vehicles were much higher than those of vehicles equipped with EFI + TWC systems, and 2-stroke motorcycles had much higher HC emission than 4-stroke motorcycles. According to the emission inventory of Macao in 2000, the mobile sources contributed 92% and 29% to total CO and NOx emissions, respectively. HC and CO emissions from motorcycles and private cars accounted for the biggest two portions of total mobile source emissions, with percentages of 70% of HC emission and 71% of CO emission. Buses, heavy-duty diesel vehicles and private cars were the biggest three contributors to total NOx emissions from mobile sources, accounting for 34%, 32% and 17%, respectively. Moreover, PM10 and PM2.5 emissions from buses, heavy duty diesel vehicles and diesel powered taxis accounted for the biggest three parts of total mobile source emissions, with percentages of 40%, 24% and 12% for PM10 and 40%, 24% and 13% for PM2.5. According to the spatial and temporal variation of mobile source emissions, the highest emission intensity happened in rush hours and busy traffic area in Macao peninsular. Using ISCST model to simulate the air pollutant dispersion in 2000, it was estimated that mobile sources contributed 99% and 82% to the ambient CO and NOx concentrations close to the ground, respectively. The low emission height of mobile sources resulted in more significant effect on ambient pollutant concentrations close to the ground of than stationary sources. In central business area, the high density of population and buildings caused "street canyon effect" on the pollutant dispersion. When approaching to ground, the effects unde

利用风洞试验，现场监测及计算机模拟研究澳门街区汽车尾气污染的原因和特征