环巢湖地区雾霾天气下不同粒径大气颗粒物中正构烷烃污染和来源解析

发布时间：2018-06-26 01:51

本文选题：环巢湖地区 + 大气颗粒物　；参考：《合肥工业大学》2016年硕士论文

【摘要】：随着社会经济的高速发展和人为活动的加剧,大气污染已成为了当前高度关注的环境问题。环巢湖地区是我国东部一个重要的经济发展区域,近年来大气污染尤其雾霾天气明显增加,严重地影响了当地人们的生活和身心健康。众所周知,大气颗粒物污染是雾霾天气的主要因素,利用分子标志物探究大气颗粒物的来源是研究雾霾形成的一个重要手段。本研究利用8级大气采样器采集了环巢湖地区12个区域大气颗粒物,分析了不同粒径中正构烷烃(C_(10)～C_(36))的浓度和组成分布特征,探讨了正构烷烃的粒径分布特征,并根据正构烷烃的特征辨析了主要来源,同时本研究收集了采样月份中合肥市区10个大气监测站点公布记录的空气质量数据(包括PM_(2.5)、PM_(10)、NO_2、 SO_2、O3和CO),分析了这些污染物的时空变化规律和影响因素,并预测了大气能见度。主要结果与结论如下：(1)合肥市区10个大气监测站公布的数据显示,PM_(2.5)是影响合肥空气质量的最关键因素,近80%的天数超过了国家空气质量标准,其次为PM_(10),约56%的天数超过了国家空气质量标准,NO_2、SO_2、CO和O_3对合肥市区空气质量影响较小。同时这些污染物均呈现明显的时空差异,其中市区污染更为严重,而12月污染最为严重。通过估算大气能见度发现,2014年10～12月期间几乎所有天数均为雾霾天气,尤其大气颗粒物分级采样时段均是雾霾天气,且是长期持续的雾霾天气。(2)环巢湖地区大气颗粒物中正构烷烃的总浓度为402-3040 ng/m~3,其中算术均值为1460±1000 ng/m~3,其中三河镇(旅游区)大气颗粒物中正构烷烃浓度最高,当地的餐饮业可能是关键因素。但并未发现环巢湖地区大气颗粒物中正构烷烃浓度呈现明显的空间差异,尤其都市区浓度并未高于郊区和农村,反映了长期持续雾霾天气下,环巢湖区域大气颗粒物污染接近。(3)不同采样点处大气颗粒物中正构烷烃的粒径分布差异较大,周边县城和乡镇地区主要富集在细颗粒物中,而市区则富集在粗颗粒物中,同时不同采样点处不同碳原子数的正构烷烃同系物在粗-细颗粒物中分布不同,反映了不同的来源。(4)环巢湖地区大气颗粒物中正构烷烃的几何平均粒径为2.61±1.21μm,工大新区最大,为5.81 μm,几何标准偏差0.43±0.06μm,其中几何平均粒径正构烷烃的饱和蒸气压呈现明显的正相关,但几何标准偏差则与饱和蒸气压呈现明显的负相关,反映了不同化合物在粒径中分布明显受其物理化学特征影响。(5)据正构烷烃组成特征分析,环巢湖地区大气颗粒物中正构烷烃来自于人为活动排放,CPI值接近于1,其中工大新区处CPI值最大。利用植物蜡碳数%waxC_n估算了环巢湖地区大气颗粒物中15.9±7.0%的正构烷烃来源于高等植物释放。
[Abstract]:With the rapid development of social economy and the aggravation of human activities, air pollution has become a serious environmental problem. The area around Chaohu Lake is an important economic development area in the east of China. In recent years, air pollution, especially haze weather, has increased significantly, which has seriously affected the lives and physical and mental health of local people. It is well known that atmospheric particulate pollution is the main factor in the weather of haze, and it is an important means to study the formation of haze by using molecular markers to explore the origin of atmospheric particulates. In this study, 12 regional atmospheric particulates in Chaohu Lake area were collected by using an 8-level atmospheric sampler. The distribution characteristics of normal alkanes (C _ (10) C _ (36) in different particle sizes were analyzed, and the particle size distribution characteristics of normal alkanes were discussed. According to the characteristics of n-alkanes, the main sources are analyzed. At the same time, the air quality data (including PM2.5 / PM10 / no _ 2, so _ 2O _ 3 and CO) published by 10 atmospheric monitoring stations in Hefei in the sampling month were collected. The temporal and spatial variation of these pollutants and the influencing factors were analyzed, and the atmospheric visibility was predicted. The main results and conclusions are as follows: (1) the data from 10 air monitoring stations in Hefei city show that PM2.5 is the most important factor affecting the air quality in Hefei, and nearly 80% of the days exceed the national air quality standard. The next is PM10, and about 56% of the days exceed the national air quality standard (NO2SO2CO3), which has little effect on the air quality in Hefei urban area. At the same time, these pollutants showed significant temporal and spatial differences, especially in urban areas, and the pollution in December was the most serious. By estimating atmospheric visibility, it is found that almost all the days from October to December 2014 are haze weather, especially for atmospheric particulate matter classification sampling period is haze weather. And it is a long-lasting haze weather. (2) the total concentration of n-alkanes in atmospheric particulates around Chaohu Lake is 402-3040 ng / m ~ (3), the arithmetic average is 1460 卤1000 ng / m ~ (3), and the concentration of normal alkanes in atmospheric particulates in Sanhe Town (tourist area) is the highest. The local catering industry may be a key factor. However, there was no significant spatial difference in the concentration of n-alkanes in atmospheric particulates around Chaohu Lake, especially in the metropolitan area, which was not higher than that in the suburbs and rural areas, which reflected the long-term persistent haze weather. The atmospheric particulate pollution around Chaohu Lake is close. (3) the size distribution of n-alkanes in atmospheric particles at different sampling points is different. The surrounding counties and towns are mainly enriched in fine particles, while the urban areas are enriched in coarse particles. At the same time, the distribution of n-alkane homologues in coarse and fine particles at different sampling points was different, which reflected different sources. (4) the geometric mean particle size of n-alkanes in atmospheric particulate matter around Chaohu Lake was 2.61 卤1.21 渭 m. The geometric standard deviation was 0.43 卤0.06 渭 m, in which the saturated vapor pressure of normal alkanes with geometric mean particle size was positively correlated, but the geometric standard deviation was negatively correlated with the saturated vapor pressure. It reflects that the distribution of different compounds in the particle size is obviously influenced by their physicochemical characteristics. (5) according to the analysis of the composition characteristics of n-alkanes, In the atmospheric particulate matter around Chaohu Lake, the CPI value of n-alkanes from anthropogenic activities is close to 1, and the CPI value is the largest in the new area. Based on the wax C _ n of plant wax, it was estimated that 15.9 卤7.0% of normal alkanes in atmospheric particulate matter in Chaohu Lake region were derived from higher plant release.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X513

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