Study On The Exhaust Emissions Of Discharge Permitting In Chengdu Based On PM_2.5 Emission Reduction Target

Although the atmospheric environment quality in Chengdu has improved obviously in recent years,there are still some problems,such as uneven spatial and temporal distribution of pollution and heavy pollution weather,which affect the health of residents under the influence of the specific topography and geomorphology of the basin and adverse meteorological conditions.In view of the exhaust emissions of the discharge permitting is no guarantee that the problem of regional air quality to achieve specific targets,this paper based on 2019 years,the statistical analysis of the meteorological characteristics of chengdu,air quality and the present situation of air pollution,the pollution emissions data collection research area and establish the emission inventory,Based on the WRF-CMAQ model,two simulation schemes were set up,the actual scenario scheme and the control scenario scheme.The actual scenario scheme verified the reliability of the model.Annual control scenario plan to chengdu PM_2.5concentrations reach"sichuan province"much starker choices-and graver consequences-in"ambient air quality and the main atmospheric pollutant total emission reduction target task decomposition plan"（hereinafter referred to as much starker choices-and graver consequences-in）corresponding requirements as the goal,through the model based on iterative method to calculate exhaust emissions of discharge permitting in chengdu based on PM_2.5 emission reduction target,It provides technical support for improving the calculation of emission permit.The main work of this paper is as follows:1.The localized emission inventory of January,April,July and October was made to obtain the emission of 9 major pollutants that form PM_2.5 in the research area grid and the corresponding time and space allocation..2.Verify the reliability of meteorological model and air quality model.The simulation results show that the meteorological simulation results of the four feature months are good,and the simulated concentrations of PM_2.5 at the four monitoring points have a good variation trend,with R² above 0.65,which is partly overestimated.The model can well simulate the concentration level of pollutants.3.Obtained the exhaust emissions of discharge permitting in chengdu based on PM_2.5emission reduction target.The maximum emission of pollutants from 316 key air management enterprises in Chengdu was obtained.When achieving the emission reduction target,the total annual emission of SO₂,NOx,primary particulate matter and VOCs declared by key air management enterprises in Chengdu should be 49431.6t,131238.3t,7098.9t and 5314.1t,respectively.Compared with the original declared emissions,36918.0t,98850.8t,5507.1t and3483.2t should be reduced respectively.Among them,the average PM_2.5 concentration in April,July and October was lower than the annual average concentration emission reduction target,and even if the declared emission reduction was zero in January,it was higher than the annual average concentration emission reduction target.4.Suggestions on the setting of emission permit emissions are put forward based on the simulation of the model.Strictly control areas with high concentrations of PM_2.5;Exhaust gas emissions increase in different seasonal policies to deal with heavy pollution in autumn and winter weather;At the same time,it should be set in accordance with the"Ambient Air Quality Standard"and the local emission reduction target to decrease year by year to meet the goal of environmental quality improvement.