The Spatial Distribution Characteristics Of VOCs Based On GIS Platform In Industrial Sources Of Chengdu

In recent years,with the rapid economic development in Chengdu,the problem of air pollution in Chengdu has become more and more serious,therefore,according to the actual condition of Chengdu,our study took 2013 year as the research year,and took 20 counties as the study area,selecting 1000 industries which the cumulative volatile organic compounds emissions accounted for more than 85%of total emissions in Chengdu,through the household survey and making use of annual emission declaration and quarterly emission declaration reporting as well as environmental reporting.We collected the information of industrial activity level.Besides,we made use of emission coefficient method to estimate the VOCs emissions,the emissions coefficient come from the national environmental protection for the volatile organic compounds(VOCs)emissions listing technical guide.As well as a four-level emission source classification system for industrial source VOCs emission inventories was constructed.The source classification system of industrial source VOCs was divided into solvent source,process source,fossil fuel combustion source and biomass combustion source.Combined with the GIS platform,demonstrating the VOCs spatial distribution of industrial sources.And further select the 12 key enterprises to measure the main components and emission concentration of the VOCs discharged from these enterprises,analyze the difference of VOCs composition among the industries,and the differences and causes of the VOCs composition of different enterprises in the same industry,and through the calculation of 12 enterprises VOCs emissions to get Chengdu local emission coefficient of the five industries.Finally,suggestions and measures are proposed for the prevention and control of air pollution in Chengdu.Through analysis,the main conclusions are as follows:(1)In 2013,the total industrial VOCs emissions of Chengdu were 5.77 X 107kg,among which the emissions of solvent sources were 3.09 × 107kg,the emissions from the process source were 2.35 X 107kg,and the emissions of fossil fuel combustion sources were 0.21 X 107kg,biomass combustion source emissions were 0.12 × 107kg.(2)In the view of the emissions contribution of industrial sources,the solvent source and the process source are the main sources of emissions,and the contribution rates are 53.55%and 40.73%respectively.Among them,paint production,automobile spraying,equipment manufacturing and furniture manufacturing are the main source of solvent use of the industry,while the process emissions are mainly from the chemical,glass,cement industry.(3)In the view of the spatial distribution of industrial sources,the larger areas of emissions are more distributed in Chengdu,two or three circle of the districts and counties,VOCs emissions of more than 1,000 tons of the grid are mainly distributed in Dujiangyan City,Pixian,Wenjiang District,Chongzhou City,Shuangliu County,Longquanyi District,Qingbaijiang District and other cities and counties.(4)In the view of the spatial distribution of the source of the solvent,the Longquanyi area is the most important source of emission,with the contribution rate of up to 73.45%,mainly from the automobile and parts manufacturing industry.Followed by Pixian and Dayi County,the contribution rate was 7.37%and 6.13%.In the view of the spatial distribution characteristics of the process source,the Qingbaijiang District is the most important contributor,the contribution rate of emissions accounted for 19.67%,mainly from the steel and chemical industry.Shuangliu County,Dujiangyan City,Wenjiang District and Pengzhou City followed.In the view of the spatial distribution characteristics of fossil fuel combustion sources,Pengzhou and Jintang counties are the main contributors,and the contribution rates are 23.87%and 22.26%respectively.The main emissions of Pengzhou City are the use of coal in cement industry,Jintang County mainly from thermal power plants.Qingbaijiang District,Jinniu District,Dujiangyan City followed.In the view of the spatial distribution of biomass combustion sources,Shuangliu County is the most important contributor,the contribution rate of emissions accounted for 74.75%,the main source for the environmental protection power generation industry.Chongzhou City and Qionglai City followed.(5)In the view of the analysis of measured data,aromatic hydrocarbons and oxygen VOCs are the main components of VOCs emission from key industries in Chengdu,and the VOCs components of different industries are different.Most of the species with large atmospheric chemical reactivity are aromatic hydrocarbons.Chengdu furniture manufacturing industry VOCs emission factor is 0.6 1kg/pieces,automotive spraying industry VOCs emission factor is 3.1kg/vehicle,footwear industry VOCs emission factor is 4.04g/double,the printing industry VOCs emission factor is 34.7g/kg ink,The VOCs emission factor for wood-based panel productiol industry is 3.67g/m~3.