Research On Atmospheric Environmental Impact Of Large-Scale Silicon Carbide Area Source Under Complex Terrain Conditions In Tianzhu County

The work of air pollution prevention and control is carried out quickly and orderly in our country,Meanwhile,There are still many enterprises using backward production methods producing a lot of air pollution,the work of air pollution prevention and control there need to be carried out.Tianzhu County,located in Wuwei City,near Qilian Mountain National Nature Reserve.And the current ambient air quality there is relatively poor.In addition,a large number of distributed silicon carbide enterprises in the region are lagging behind,the production of the wide-groove industrial park and its surrounding silicon carbide enterprises in the region accounted for 13%of the domestic silicon carbide production,and the industrial scale was large,which made great contributions to the economy of Tianzhu County.However,the silicon carbide companies have a huge impact on the surrounding environment in the form of contiguous unorganized sources.At the same time,the terrain conditions in the area are complex,which is not conducive to the diffusion of pollutants.Therefore,studying the influence of unorganized surface source of silicon carbide enterprises on the ambient air quality in the region is of great significance for the future prevention and control of air pollution in this region.This paper investigates the production of silicon carbide enterprises in Guanggou Industrial Park,Tianzhu County,Wuwei City,and analyzes the environmental air quality of the area under the influence of contiguous surface sources.At the same time,calculates the actual pollution source of SiC enterprises,Finally,run the CALPUFF air quality model recommended by the model management department of the Ministry of Ecology and Environment to study the influences and characteristics of atmospheric pollutants in different levels of sewage and the typical seasonal conditions of the silicon carbide enterprises based on local meteorological and topographic data.Clarify the nature and extent of environmental impacts of silicon carbide production parks on environmental impacts.The main findings include:?1?Conducted on-the-spot investigation and related literature review of the production of silicon carbide enterprises,and found out the actual production status,According to the sensitive point concentration monitoring data,the concentration of the silicon carbide enterprise based on CALPUFF was calculated by the concentration back-calculation method and the K-means clustering method.The conclusions are as follows:The distribution of silicon carbide enterprises in Kuangou,Shuiquan and Dachaigou Parks is highly concentrated,and contiguous and large-scale non-point source pollution has been formed.The existing silicon carbide production methods are rough and the traditional technology level is backward.Only some enterprises have matched the furnaces and kiln to organize the construction of treatment engineering facilities for the emission of flue gas.In addition,the source of sewage of silicon carbide enterprises fluctuates with the change of production cycle,which can be roughly divided into three states:high level sewage discharge,medium level sewage discharge and low level sewage discharge.The total source strength of SiC enterprises in the area under high level sewage is SO₂:274.60kg/h;NO_X:65.51 kg/h;CO:2140.09 kg/h;NH₃:116.35 kg/h;H₂S:4.87:kg/h;PM₁₀:90.33 kg/h.The total source strength of SiC enterprises in the area under medium sewage level is SO₂:147.16kg/h;NO_X:24.13 kg/h;CO:1354.04 kg/h;NH₃:38.81kg/h;H₂S:2.02:kg/h;PM₁₀:51.02 kg/h.The total source strength of the silicon carbide enterprises in the area with low sewage level is SO₂:41.99kg/h;NO_X:7.44 kg/h;CO:543.74 kg/h;NH₃:5.06kg/h;H₂S:1.10:kg/h;PM₁₀:8.85 kg/h.The overall production of silicon carbide is characterized by“high level of sewage discharge and low level of pollution control”.Affected by the sewage discharge of silicon carbide,many pollution factors such as SO₂,CO,PM₁₀,PM_2.5,NH₃ and H₂S exceeded the standard in the study area,and the research area is the non-standard area for ambient air quality at present.?2?Using the CALPUFF model to predict the sewage situation of the wide-groove park and surrounding silicon carbide enterprises in Tianzhu County,analyze the pollution situation and its impact characteristics of the year and the year with the representative months of January,April,October and October.It is found that the unorganized surface source pollutants of silicon carbide enterprises in the study area spread downstream along the valley topography,and the closer the pollution source is,the worse the ambient air quality is.The environmental air in the Kuangou Village and the west side of Shibanwan Village is directly and most seriously polluted by the Guanggou Industrial Park.The villages near the Chaigou Industrial Park in Chaigou Town are highly polluted by silicon carbide production.The villages downstream of Shuiquan Park have also failed to meet the basic requirements of the corresponding environmental air function.The main over-standard factors around each park are SO2,H2S,CO,NH3,PM₁₀ matter,etc.The diffusion of non-point source pollutants in various silicon carbide enterprise parks basically shows the decreasing concentration of the surrounding sources from the surface source,affecting sensitive points with close distance.At the time when the silicon carbide enterprises produced the most serious sewage discharge,the sensitive points along the Zhuanglang River valley basically caused the pollutant concentration to exceed the standard.The average average contribution of silicon carbide enterprises to Tianzhu County's concentration is 10.04%,the largest average ratio is 30.09%,and the single largest contribution is 73.9%.Both indicate that silicon carbide production has a greater impact on the county environment.The research results show that the sewage disposal of silicon carbide enterprises has a greater contribution to the excessive environmental air quality in the region.In order to ensure the concentrated residential areas around the silicon carbide production park,the adjacent Qilian Mountain Nature Reserve meets the environmental standards,and improve the ambient air quality of the county,there is an urgent need to comprehensively control the emission of atmospheric pollutants from the wide trench industrial park and surrounding silicon carbide enterprises.