Establishment Of Anthropogenic Air Pollutant Emissions Inventory In Yumen City

With the advancement of urbanization and industrialization,many pollutants released into the air by pollution sources,including industrial combustion source,civil combustion source,production process source,traffic exhaust and dust source,have seriously affected the atmospheric environment,and caused a lot of air pollution problems.It has gradually become one of the important environmental issues that cannot be ignored.The air quality numerical model system is one of the important method to study environmental issues,It is widely used in the treatment of air pollution problem and environmental quality management at home and abroad.Source emission inventory is the basic work of air quality numerical model which will directly affect the reliability of numerical model simulation results.The establishment of localized source emission inventory can effectively understand the time-space distribution of pollutants.It is significant to scientifically assess the causes of atmospheric pollution,improve the simulation effect of air quality model,and further propose effective pollution control measures.In this study,Yumen City was used as the research area.First,collecting many datas such as emission factors and activity levels of different air pollutants through extensively research.The air pollutant emissions of 8 types of primary emission sources covering industrial source,electric power source,civilian source,agricultural source,dust source,storage and transportation source,waste treatment source and solvent application source in Yumen City were calculated,mainly including SO₂,NOx,NH₃,CO,VOCs,PM₁₀0 and PM_2.5,and the spatial distribution of the emission list,and this article established a localized anthropogenic source emission inventory for Yumen in 2018.The inventory was compared with the Multi-resolution Emission Inventory for China inventory and simulated using the Community Multiscale Air Quality air quality model to verify the Yumen City emissions inventory.The main conclusions of the paper are as follows:（1）In 2018,the excellent and good days of Yumen City made the air quality compliance rate reach 78.36%.The air quality was the best in summer（July-September）.The pollution was serious in winter and spring,and the main pollutant was particulate matter.The concentrations of SO₂,NO₂ and CO were lower in summer and higher in winter.The concentrations of O₃ was higher in summer than in other seasons.The concentrations of PM_2.5.5 and PM₁₀0 were highest in spring.（2）This article established a localized anthropogenic source emission inventory for Yumen in 2018.The types of emission inventory include eight types of primary emission sources,including industrial source,electric power source,civilian source,agricultural source,dust source,storage and transportation source,waste treatment source,and solvent application source.The annual emissions of SO₂,NO_x,NH₃,CO,VOCs,PM₁₀0 and PM_2.5.5 were 2268.62,3326.94,3204.59,19627.18,3383.48,2895.39 and 1641.46 tons,respectively.Excepting NH₃ which was mainly from agricultural source,industrial source was the main contributor to the other six pollutants.The power source was the second contribution source of SO₂ and NO_x.The contribution of civilian source to CO,VOCs,PM₁₀0 and PM_2.5.5 were lower than industrial source.The contribution of storage and transportation source,waste treatment source,and solvent application source were minimal.（3）Analyzing the contribution of different industries in the industrial source to the emissions of major pollutants:Coking industry was the main source of SO₂,NO_x,NH₃,PM₁₀0 and PM_2.5,accounting for 51.43%,54.58%,55.00%,32.44%and 40.76%,respectively.The contributions of PM₁₀0 and PM_2.5.5 from cement manufacturing industry were lower than the coking industry.Lime manufacturing industry was the main source of CO,with a contribution rate of 53.93%.Petroleum processing industry was the main source of VOCs,accounting for 25.63%,followed by the coking industry.（4）The main sources of atmospheric pollutants from civil source were straw domestic combustion and straw open burning,the contribution rates of SO₂,NO_x,NH₃,CO,VOCs,PM₁₀0 and PM_2.5.5 were 65.04%,89.09%,63.08%,82.17%,89.36%,84.89%and 90.95%,respectively.The atmospheric pollutants generated by the power source were all derived from the combustion of coals.For NH₃ emissions which comes from agricultural source,66.98%of NH₃ emissions were from livestock and poultry farming.30.95%of NH₃ emissions were from application of nitrogen fertilizer.For dust source,PM₁₀0 and PM_2.5.5 were mainly from construction dust source,the contribution rates were 64.04%and 55.89%for PM₁₀0 and PM_2.5,respectively,followed by yard dust source,accounting for 35.96%and 44.10%,respectively.Storage and transportation source and solvent application source only generated VOCs.Waste treatment source mainly produced the emission of NH₃ and VOCs,of which solid waste treatment was the main contribution source of NH₃,accounting for98.70%.（5）The spatial distribution of pollutants showed that six pollutants,including SO_2,NO_x,CO,VOCs,PM₁₀0 and PM_2.5,were mainly distributed in three parks in Yumen city,namely Yumen Industrial Park,Yumen East Industrial Park and Laojunmiao Industrial Park.The Laojunmiao Industrial Park and Yumen East Industrial Park had relatively larger emissions.The spatial distribution characteristics of NH₃ emissions were inconsistent with other sources.The main reason was that93.41%of NH₃ emissions were from agricultural source,the application of nitrogen fertilizer and livestock and poultry farming mainly used cultivated land for spatial distribution.（6）Using CMAQ to verify the emission inventory of Yumen City,the results showed that the emission inventory of Yumen City was more representative and reasonable.（7）The impact of industrial source which was a key source of emissions on SO₂ and NO₂ concentrations in Yumen city was evaluated by using the CMAQ model.The contribution rates of emissions from industrial source to the average concentration of SO₂ and NO₂ at Tongbanlou station were 65.83%and 51.49%,respectively,and the contribution rates to Yumendongzhen station were 78.30%and59.30%,respectively.The contribution rate of emissions from industrial source was contributed significantly to the concentration of SO₂ and NO₂ at the Yumendongzhen station.