The Study On Emission Standards For Main Sources Of NOx And Simulation Of Their Environmental Impact

As the key pollutant of the atmospheric combined pollution, NOx has gradually become the environmental focus in the countries all over the world for bringing a series of environmental problems. It can effectively reduce the NOx pollution in China to strengthen the control of NOx emission from its two main sources:Motor vehicles and power plants. At present, the emission standards of power plants have been revised in our country, and the related research of NOx emission control have been carried on.Considering the current requirements of vehicle emission control, three kinds of schemes and six scenarios were designed on the basis of research of the emission standards of power plants. We used the integrated air quality mode (CMAQ) to simulate the environmental impact of the implementation of the two new emissions:power plants and motor vehicles standards. And the effect of implementation of the new emission standards were analyzed, furthermore the control levels of the new emission standards were evaluated and future direction of NOx emission control in China were also discussed.Based on the research of the atmospheric pollutants of our country at home and abroad, the pollution sources were divided into point sources, non-point sources (mobile source included) and biological sources. For thermal power point source, the whole country was divided into eight regions, according to the national economic development and coal energy consumption. And we calculated the growth of thermal power unit in every region for nearly 10 years,from which the total growth of thermal power unit in every region were extrapolated to 2015 and 2020, and estimated the pollutant emission. For non-point sources, based on the estimation of the total emission, spatial-time and species allocation of pollutants were used. Finally, the SMOKE mode ran to generate data that CMAQ needed.The results showed that it could effectively reduce the deterioration trend of regional air quality and acid subsidence through implementation of the new emission standards of power plants. By 2020, the area of NO2 concentration higher than 0.04mg/m3 reached 1.36x105km, reducing by 54.3% compared with that of the current standards; and the area of nitrogen deposition higher than 1.0gN/m2·a reached 6.1×105km2, reducing by 69.7% compared with that of the current standards. The amount of total nitrogen is 3.48×109kg, reducing by 23% compared with that of the current standards. From this study, we can conclude that it is quite obvious that the regional air quality will improve a lot through implementation of the new emission standards of power plants.Implementation of the new emission standards of Motor vehicle, could also improve regional air quality and reduce acid subsidence, but the effect was not quite obvious. The results showed that the situation of the NOx pollution was close to that of 2007, and still a little serious. Meanwhile, in some megapolis where vehicle emissions dominated, such as Beijing etc.., the situation of NO2 pollution did not get fundamental improvement.After comprehensive analysis of the control process and current emission standards of power plants at home and abroad, we can conclude that the new emission standards of power plant has reached international leading level. In order to reduce NOx pollution situation of regions and megapolis, it is necessary to further strengthen the emission controls of pollutants from motor vehicles and other industries. This will also be the keypoint of the future NOx control in our country.