Research On Anthropogenic Emissions And Control Of Primary Particles And Its Key Chemical Components

Paticulate matter (PM) plays an important role in complex regional air pollution in China. Understanding the characteristics of PM emissions is essential to study the pattern of complex regional air pollution and to fumulate control strategy. The purpose of this study is to develop high-resolution emission inventories of PM through estabulishing a set of methods, analyse the historical trends and spatial distribution of emissions of PM and its key chemical components, and then assess the influence of Mid-and-Long term air quality control strategies on emissions and atmospheric concentration of PM by applying air quality model.Firstly, a set of methods, involving a database and several models for the activitiy information of 53 types of emission sources with the classification of 4th level, and functions between technology level and inter-annual emission factors for each type of emission sources, were established for developing high-resolution emission inventories of PM in China.Based on these methods, inter-annual anthropogenic emissions of PM by 3 size ranges and 4 key chemical components during the year of 1990~2005 were estimated, a unit-based emission inventory for point sources of power, cement, iron & steel industry was also developed for the year of 2005. Characteristics of PM emissions from each sectors in China, as well as its driven force from changes of energy and industry activities and technology improvement, was analysised thereby. Trend of anthropogenic PM emissions in China changed in the year of 1996, 2000, and 2004, and the maximum PM emissions took place in the year of 1996, with 35.48 Tg of TSP, 18.51 Tg of PM10, and 11.97 Tg of PM2.5 emitted. Cement industry and biomass combustion in domestic sector are the most important sources of PM2.5 emissions. Timbering industry contributes more than 50% of TSP emissions. Distribution of PM emissions and its trends shows great regional differences: Shandong, Hebei, Jiangsu, Henan, Guangdong and Sichuan contribute 40% of PM2.5 emissions in China.Emissions of BC and OC kept increase during the year of 1990~2005; while emissions of base cations declined after the year of 1996, probably resulting in more acid depositions.Based on the emission inventory for the year of 2005, air quality under various emission control policy scenarios in the year of 2020 was simulated with Community Multi-scale Air Quality Model (CMAQ). Current and enhanced control policies can eliminate PM10 non-attainment areas in the year of 2020, according to current air quality standard, but there will wtill be 13.1% of national aera with annual PM2.5 concentration above interrium target of World Health Organasition, and the high PM2.5 concentration occurs in the area with high population density such as Norch China, Middle China and Sichuan basin. Propotion of nitrate in PM2.5 will increase significantly under all scenarios, though concentration of PM2.5 will decline. The results indicate that programs to control NOx emissions in China should be formulated and launched as soon as possible to abate the formation of secondary nitrate.