Study On Dust Emission Characteristics Of Transportation And Construction Sites In Hengyang City

With the progress of urbanization in Hengyang City,the pollution of atmospheric particulate matter is becoming more and more serious.Dust emission from traffic and construction sites has become the main source of atmospheric particulate matter pollution.However,few studies have been done on the characteristics of dust emission from traffic and construction sites in Hengyang City,especially the localization of emission factors.In order to provide data support and theoretical basis for decision-making of dust control and related departments in Hengyang City,a deep research on dust is carried out.Firstly,Thesis uses AP-42 method to set up road dust emission factors through road sampling and experimental study in Hengyang City.The results show that the average emission factors of TSP,PM₁₀ and PM_2.5 are 6.39,1.23 and 0.30g/m²,respectively.The maximum emission factors of TSP,PM₁₀ and PM_2.5 are branch roads,which are 7.16,1.37 and0.33g/m²,The emission factors of TSP,PM₁₀ and PM_2.5 in main roads are the smallest,which are 5.87,1.14 and 0.27g/m².Based on FDM model,the actual emission factors of dust in different construction stages of Hengyang City are established.The actual emission factors of earthwork foundation stage,main structure construction stage and decoration stage are 0.449,0.177 and 0.149g/（m².h）.Secondly,the total emissions of TSP,PM₁₀ and PM_2.5 from October2016 to November 2017 are 482.47t,92.62t and 22.39t,and the total amount of fugitive dust in Hengyang city is 2424.8t,including 1290.99t,848.20t and 285.61t in earthwork foundation stage,main structure construction stage and decoration stage,respectively.Thirdly,this paper studies the temporal variation and spatial distribution characteristics of dust in Hengyang City.The results show that the monthly average concentration of particulate matter in Hengyang City is the highest in December and the lowest in July,mainly due to the low temperature in winter,poor atmospheric diffusion conditions and less rainfall.The dust emission mainly concentrates in Shigu District and Zhenxiang District,which is due to the large-scale development and construction of Laiyan New Town.Finally,according to the questionnaire survey and on-site investigation,this paper summarizes the main problems of dust control in Hengyang traffic and construction sites:lack of relevant laws and standards,insufficient road cleaning and sprinkler level,inadequate implementation of specific prevention and control measures,etc.To solve these problems,the first thing is to improve the laws and regulations of dust control and improve the management of dust control、Mechanisms and responsibility system,popularization of ready-mixed mortar,strengthening supervision and management of construction site,etc.