淄博市大气重污染过程污染来源及其与气象条件的关联性分析

发布时间：2018-04-15 21:00

本文选题：大气重污染过程 + 污染来源　；参考：《山东师范大学》2017年硕士论文

【摘要】：近几年淄博市的大气污染问题较为严重,目前该地区大气污染治理的主要困难是对各污染来源对当地大气污染的具体贡献占比研究较少,且局地和区域气象条件对淄博市大气重污染过程的影响方式、影响程度研究尚少。本文通过实地调查、数据统计、查阅资料等方法获取淄博市2015年的空气质量、气象条件以及大气污染物排放数据,选取典型大气重污染过程,确定主要大气污染物排放清单并将清单结果输入RAMS-CMAQ模型,利用模型对典型重污染过程进行数值模拟,解析重污染过程污染来源,再分析重污染过程与气象条件的关联性。本文研究成果如下:(1)淄博市大气污染来源:(1)综合各污染过程来看,除过程三(3月27日-4月6日)是风沙天气造成的PM10爆发增长外,其余污染过程均以化学转化造成的PM2.5二次污染为主,硫酸盐对PM2.5二次组分的贡献占比最大,总体占比超过30%,硝酸盐次之,占比约为18%,有机碳、铵盐占比均约为15%。除风沙天气一次颗粒物对PM2.5贡献超过18%外,一次颗粒物、黑碳的的贡献在10%左右。当硫酸盐贡献明显较高且SO2浓度较大时,重污染主要来自于本地排放积累,而当硝酸盐贡献与硫酸盐相当且NO2浓度较低时,重污染主要来自于区域输送。(2)从冬季(1月)污染特征来看,除硝酸盐外,本地排放对淄博市冬季大气污染贡献超过80%,周边区域输送约占20%;硝酸盐区域输送超过40%。在本地排放源中,工业源总体占比超过40%,是最主要的污染来源,民用源、电力源也有较明显贡献,分别约占15%,扬尘源、农业源、移动源贡献较小。(2)淄博市大气污染与气象条件关联性:(1)风速、混合层高度对空气质量的影响程度大于其他气象条件,在局地或区域处于小风(风速小于2.0m/s)或静风天气、平均混合层高度小于200m时,污染物大量积累并发生重污染,且小风(或静风)天气、低混合层高度持续越久,重污染持续越久甚至加重。结合淄博市地理位置来看,当局地或区域风向为西北或东北且风速较大时,利于污染物的扩散。(2)相对湿度对空气质量的影响较为明显,在局地或区域持续高湿(相对湿度大于70%)状态下,污染物较大量积累,但在湿度饱和形成降水时,污染减轻。(3)从局地气温、气压可观察冷(暖)锋过境情况,当气温降低(升高)、气压升高(降低)时,表明有冷(暖)锋过境,且气温、气压变化幅度越大(小),锋面移动速度越快(慢);冷锋过境后,污染减轻。温度层结与空气质量有较明显的关系,当在150~250m高度处发生逆温且逆温层厚度超过100m、逆温持续时间超过24h时,污染物较大量积累。从区域气压场来看,均压场和区域等压线稀疏是造成污染物积累和重污染发生的重要原因。(4)抬升指数能够较好地表征大气稳定度,当抬升指数变小时,大气稳定程度的减小有利于污染物的扩散。
[Abstract]:In recent years, the problem of air pollution in Zibo City is more serious. At present, the main difficulty of air pollution control in this area is that the specific contribution of various pollution sources to local air pollution is less studied.The influence of local and regional meteorological conditions on the process of heavy air pollution in Zibo City is still few.In this paper, the data of air quality, meteorological condition and emission of atmospheric pollutants in Zibo City in 2015 are obtained by field investigation, data statistics, data retrieval and so on, and typical atmospheric heavy pollution processes are selected.The emission inventory of major atmospheric pollutants is determined and the results of the inventory are input into the RAMS-CMAQ model. The typical heavy pollution process is numerically simulated by the model. The source of the heavy pollution process is analyzed, and the correlation between the heavy pollution process and the meteorological conditions is analyzed.The research results of this paper are as follows: 1) the source of air pollution in Zibo city, the source of air pollution, is: in the light of each pollution process, except for process 3 (March 27-April 6), which is caused by wind and sand weather, the PM10 burst increases.The other pollution processes are mainly caused by chemical transformation of PM2.5 secondary pollution, the contribution of sulfate to the secondary components of PM2.5 is the largest, the total proportion is more than 30, nitrate is the second, the proportion is about 18, organic carbon, ammonium salt is about 15 percent.The contribution of single particulate matter to PM2.5 was more than 18%, and that of black carbon was about 10%.When sulfate contribution is obviously high and SO2 concentration is high, heavy pollution mainly comes from local emission accumulation, but when nitrate contribution is equivalent to sulfate and NO2 concentration is low,Heavy pollution mainly comes from regional transport. (2) according to the characteristics of pollution in winter (January), except for nitrate, the contribution of local emissions to air pollution in Zibo in winter is more than 80,20 percent in surrounding areas, and more than 40 percent in nitrate regions.Among the local emission sources, the overall industrial source accounts for more than 40 percent, which is the most important source of pollution. Civilian sources and power sources also contribute more obviously, accounting for about 15 percent, dust sources, and agricultural sources, respectively.The relation between air pollution and meteorological conditions in Zibo City is: 1) Wind speed, mixed layer height have greater influence on air quality than other meteorological conditions, and there is a small wind (wind speed less than 2.0 m / s) or still wind weather in local or regional area.When the average height of mixing layer is less than 200 m, the pollutant accumulates and heavy pollution occurs. The longer the height of low mixing layer is, the longer the heavy pollution lasts, and the more serious the pollution is, the more severe the pollution is.According to the geographical location of Zibo City, when the local or regional wind direction is northwest or northeast and the wind speed is large, the relative humidity has a more obvious effect on air quality.Under the condition of local or regional continuous high humidity (relative humidity > 70), the pollutant accumulates in large quantities, but when the humidity saturation forms precipitation, the pollution is reduced. 3) from the local temperature, the air pressure can observe the transit of the cold (warm) front.When the temperature decreases (rising, the pressure increases), it indicates that there is a cold (warm) front crossing, and the larger the change of temperature and pressure is (small), the faster the front moves (slowly; after the cold front passes, the pollution is reduced.The relationship between temperature stratification and air quality is obvious. When the temperature inversion occurs at a height of 150 ~ 250m and the thickness of the inversion layer is more than 100m, and the temperature inversion duration is more than 24 hours, the pollutant accumulates in a large amount.From the point of view of the regional pressure field, the uniform pressure field and the sparse isobaric line are the important causes of pollutant accumulation and heavy pollution. The uplift index can better characterize the atmospheric stability, and when the uplift index becomes smaller,The reduction of atmospheric stability is beneficial to the diffusion of pollutants.
【学位授予单位】：山东师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X51;X16

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