气象条件对点源排放二噁英模拟的影响规律研究

Study of the influence of meteorological condition to modeling the transformation of dioxin emitted by point source

为了对点源排放的固相颗粒物上二噁英大气扩散规律进行认识,选择周边为复杂地形的杭州某危险废物处置设施为研究对象。使用AERMOD模型,人为设置一系列风速、风向条件,并假定二噁英均在PM2.5上,进而分析PM2.5上二噁英在这些设定的气象条件下的扩散规律,从而认识其扩散规律。结果显示:(1)风速风向对最大落地浓度、最大落地浓度点距离排放源的距离(简称最大落地点距离)的影响较大,而地貌的不同也会有一定影响。(2)3.0m/s的风速时最大落地点距离达到最大(约800m),5.0m/s的风速时最大落地浓度达到最大。(3)地形的改变对最大落地点距离的影响有限。(4)在特定风速情况下,沿风向方向,二噁英落地浓度会出现双峰现象。

To study the atmospheric transport of particle phase dioxin emitted by point source,this paper selected a point source surrounded by complex terrain in Hangzhou to research and analyze the pattern of the transformation of particle phase dioxin by using AERMOD with a series of artificial meteorological conditions （wind speed and wind direction） and assuming the diameter of particle with dioxin was 2.5μm. The result showed： （1） wind speed and wind direction affected the transport of dioxin seriously, and the land use type showed some influence on it. （2） The the distance from the maximum concentration receptor to the source reached its maximum, 800 m, when the wind speed reached 3.0 m/s, while the concentration of receptor reached its maximum when the wind speed reached 5.0 m/s. （3） Terrain showed little influence to the distance from the maximum dioxin concentration receptor to the source. （4） Under certain wind speed, the concentration of dioxin on the ground along the wind direction could have double peaks.