泰山颗粒汞污染特征和大气传输的研究

发布时间：2018-04-14 00:08

本文选题：颗粒汞 + 后推气流轨迹　；参考：《山东大学》2017年硕士论文

【摘要】：大气汞因其具有的高毒性及特殊的物理化学特性被认为是一种重要的全球性污染物。研究表明,亚洲是全球人为源排汞量最大的地区,而中国被认为是汞排放量最大的国家之一。山东作为中国重污染城市,大气汞的相关研究较少,尤其是山东高山地区的大气汞研究数据还处于空白阶段。本研究于2015年6月-2015年8月,在泰山山顶采样点利用中流量PM_(2.5)采样器采集了 43个有效样品,并对其PM_(2.5)及PHg浓度水平、影响因素、污染来源及长距离传输的影响进行了分析。结果显示,采样期间,泰山站点PM_(2.5)和颗粒汞的浓度变化趋势并不相同,其对应均值分别为68.53μgm-3、67.98 pg m-3,该浓度水平虽然低于国内城市站点,但要明显高于其他高山站点和偏远地区站点,也明显高于国外城市站点。泰山的PM_(2.5)和PHg浓度水平说明泰山作为高山站点,明显受到了人为污染源的影响。泰山污染物与风速、气压、气温等气象条件的相关性分析结果显示,泰山PM_(2.5)上的汞含量与温度有显著的负相关关系。该相关性结果表明,在低温条件下,PM_(2.5)上存在较高的大气汞吸附作用,会直接导致PM_(2.5)上的汞含量增加。受主导风向影响,采样期间E类气团(东部来向气团)对泰山的贡献频率最高,达到40.5%,但由于沿海地区受到来自海洋的东南季风影响,E类气团整体污染物浓度水平较低。S类气团(南部来向气团)的PHg及PHg/PM_(2.5)浓度均值均最高,分别为91.50 pg m-3,3.13 μg g-1,该结果显示站点南方城市内可能存在集中的大气汞排放源,而S类气团东南方向三个轨迹集中气团的高PHg浓度则表明,S类气团东南方向极可能存在集中的汞排放源。而W类气团(西部来向气团)的贡献频率和污染物浓度均值都属于4类气团中的最低值,这与采样点西部地区相对低的汞污染水平和西部气团的高空传输路径有关。针对每个样品的后推气流轨迹分析结果表示,在长距离传输中,气团的来源地、移动速度及移动路径高度都会对气团的污染物含量有明显影响。利用NO,NO_2,NO_X,SO_2,CO,O_3等气体污染物数据与颗粒汞的相关性分析发现,SO_2与PHg呈现显著正相关,说明燃煤排放源对泰山采样期间的PHg浓度起主要贡献。此外,利用潜在源分析法对泰山PHg进行的潜在源区定位结果显示,泰山PHg主要来自于山东本地、安徽淮北和江苏徐州等区域的贡献,其中以山东本地的贡献为主。
[Abstract]:Atmospheric mercury is regarded as an important global pollutant due to its high toxicity and special physical and chemical properties.Research shows that Asia has the largest anthropogenic emissions of mercury in the world, while China is considered one of the largest emitters of mercury.As a heavily polluted city in China, there are few studies on atmospheric mercury in Shandong Province, especially in the alpine areas of Shandong Province.From June 2015 to August 2015, 43 effective samples were collected at Taishan Peak sampling site using medium-flow PMstack 2.5) sampler. The concentration level of PHg, the influence factors, the source of pollution and the influence of long-distance transport were analyzed.The results showed that during the sampling period, the change trend of PMSP 2.5) and particulate mercury concentrations at Taishan station was not the same, and the corresponding mean values were 68.53 渭 g m ~ (-3) or 67.98 PG m ~ (-3) respectively, which were lower than those of domestic urban sites.But higher than other mountain sites and remote areas, also significantly higher than foreign urban sites.The concentration level of PHg and PMSP in Taishan, as a high mountain station, were obviously affected by anthropogenic pollution sources.The results of correlation analysis between pollutants and meteorological conditions such as wind speed, air pressure and temperature showed that the mercury content in Tai Shan PMgas 2.5) had a significant negative correlation with temperature.The results show that there is a higher mercury adsorption in the atmosphere at low temperature, which will directly lead to the increase of mercury content in PMSP 2.5).Under the influence of dominant wind direction, class E air mass (eastward air mass) contributed the highest frequency to Taishan during sampling period.It reached 40.5, but the concentrations of PHg and PHG / PM2.5 of class E air mass were the highest in the coastal area because of the influence of the southeast monsoon from the sea on the overall pollutant concentration level of class E. S air mass (from the south to the air mass).91.50 PG m-3 and 3.13 渭 g g-1, respectively, indicating that there may be concentrated atmospheric mercury emissions in the southern cities of the site,On the other hand, the high PHg concentration of the concentrated air mass in the southeast direction of the S type air mass indicates that there may be a concentrated mercury emission source in the southeast direction of the S type air mass.The contribution frequency and the average pollutant concentration of the W type air mass belong to the lowest of the four types of air mass, which is related to the relatively low mercury pollution level in the west of the sampling point and the high altitude transport path of the western air mass.According to the analysis of the backthrust air flow trajectory of each sample, it is shown that the origin of the air mass, the moving velocity and the height of the moving path have obvious influence on the pollutant content of the air mass during the long distance transport.Based on the analysis of the correlation between the data of gas pollutants such as no _ (no _ 2) _ O _ (2) and PHg _ (2) and particulate mercury, it is found that the coal-fired emission sources mainly contribute to the concentration of PHg in Taishan during the sampling period.In addition, the potential source of Taishan PHg was determined by the potential source analysis method. The results showed that the PHg of Mount Tai mainly came from Shandong, Anhui, Huaibei and Xuzhou, among which the contribution of Shandong was the main contribution.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X513

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