雾霾季节上海大气颗粒物中可溶性碳和离子的来源研究

发布时间：2018-04-30 18:16

本文选题：雾霾 + PM2.5　；参考：《上海师范大学》2017年硕士论文

【摘要】：本论文采集了上海市雾霾期间大气颗粒物样品共95份,用离子色谱法分析了雾霾季节上海市大气颗粒物PM2.5中水溶性离子的化学组分和各离子在不同粒径中的分布特征;用TOC法分析了雾霾季节上海市大气颗粒物PM2.5中水溶性有机碳和无机碳的质量浓度和碳在不同粒径中的分布特征。用SPSS软件对数据进行主因子分析,解析了上海市大气颗粒物中各离子和碳的来源。采样点为上海师范大学徐汇校区,采样的月份为2015年的12月,2016年1、2和3月份,通过数据分析可以得的结论如下:(1)对PM2.5中阴阳离子进行离子平衡分析,12月、1月、2月和3月这4个月份阴阳离子的相关性较好,相关系数在0.94~0.95之间,阴阳离子平衡性良好。阴阳离子的月平均摩尔浓度比在0.9675~1.52之间,水溶性离子整体上呈现偏酸性或弱碱性。(2)NO_3~-的质量浓度为12.63μg/m3,占PM2.5离子的总质量的百分比最高,上海市大气颗粒物PM2.5最主要的污染物是NO_3~-。排在第二位的是SO_4~(2-),质量浓度为8.52μg/m3,所占最高的比例高达26.42%。所占总离子质量分数百分比排在第三位是的是NH4+,质量浓度为6.79μg/m3,其在2月份最高,为22.75%。上海市大气颗粒物PM2.5中质量浓度大小关系为:NO_3~-SO_4~(2-)NH4+。(3)采样的月份中,12月份和1月份各离子浓度最高,表明这两个月的的污染最严重,三月份的离子浓度水平最低,表明污染程度最轻。2月份介于1月份和2月份之间,污染程度水平也是介于两者之间,这种浓度水平分布现象和我国每年的雾霾污染最严重的时间一致的,12月份和1月份污染最严重。(4)上海市大气颗粒物平均总离子质量浓度主要集中在细颗粒物中,最主要集中0.4~1.1μm之间。(5)上海市大气颗粒物PM2.5中水溶性离子NO_3~-/SO_4~(2-)的比值远高于其他城市,移动源对上海大气颗粒物PM2.5中水溶性离子的贡献比例最大,主要的移动源有汽车尾气排放,二次污染物,道路尘和建筑尘。机动车尾气、燃煤排放、生物质燃烧以及道路尘,其中机动车尾气贡献占主导。(6)雾霾季节上海市大气颗粒物中OC在细颗粒物中的总质量浓度均稍高于在粗颗粒物中的总质量浓度,12月份大气颗粒物中的IC也有类似的分布规律特征,IC在细颗粒物中总质量浓度稍高于在粗颗粒物中总质量浓度;而在2、3月份大气颗粒物中的IC却有相反的分布规律特征,IC在细颗粒物中总质量浓度稍低于在粗颗粒物中总质量浓度;在1月份上海市大气颗粒物中的IC因为在各粒径段均匀的分布,所以IC在细颗粒物中总质量浓度约等于在粗颗粒物中总质量浓度。(7)PM2.5中OC与HCOO-、NO_3~-、SO_4~(2-)、BrO_3~-、NH4+和K+这6种离子的来源有很大的关联。
[Abstract]:In this paper, 95 samples of atmospheric particulates during haze in Shanghai were collected. The chemical composition of water soluble ions in the atmospheric particulate matter (PM2.5) and the distribution characteristics of the ions in different particle sizes were analyzed by ion chromatography. The water soluble organic carbon in the atmospheric particles in Shanghai City, Shanghai, was analyzed by TOC. The mass concentration of inorganic carbon and the distribution characteristics of carbon in different particle sizes. The data were analyzed by SPSS software, and the sources of ions and carbon in the atmospheric particles in Shanghai were analyzed. The sampling point was the Xuhui campus of the Shanghai Normal University. The month of sampling was December in 2015, and in 2016 1,2 and March. The data can be obtained by data analysis. The conclusions are as follows: (1) the ion balance analysis of yin and Yang in PM2.5, in December, January, February and March, the correlation of yin and yang ions is better, the correlation coefficient is between 0.94~0.95, and the balance of yin and yang ions is good. The monthly mean molar concentration ratio of Yin and yang ions is between 0.9675~ 1.52 and water soluble ions appear to be acidic or weak on the whole. (2) the mass concentration of NO_3~- is 12.63 mu g/m3 and the percentage of the total mass of PM2.5 ions is the highest. The main pollutant of Shanghai atmospheric particulate matter PM2.5 is NO_3~-. in second place SO_4~ (2-), the mass concentration is 8.52 mu g/m3, and the highest proportion of the total amount of total ion mass fraction of 26.42%. is third. NH4+, the mass concentration is 6.79 mu g/m3, which is the highest in February. The mass concentration in the atmospheric particulate PM2.5 of 22.75%. Shanghai city is the relation of the mass concentration in the month of NO_3~-SO_4~ (2-) NH4+. (3), the highest concentration of each ion in December and January, indicating that the two months of pollution is the most serious, the level of the ion concentration in March is the lowest, indicating the degree of pollution. The lowest.2 month is between January and February, and the level of pollution is also between the two. This concentration level distribution is in accordance with the most serious time of haze pollution in China, and the most serious pollution in December and January. (4) the average total ionic mass concentration of atmospheric particulates in Shanghai is mainly concentrated in fine particles. The main concentration of 0.4~1.1 mu m. (5) the ratio of water soluble ion NO_3~-/SO_4~ (2-) in Shanghai atmospheric particulate matter (PM2.5) is far higher than that of other cities. The contribution of mobile sources to the water soluble ions in the particulate matter of Shanghai is the largest. The main sources are vehicle exhaust, two pollutants, road dust and building dust. Motor vehicle exhaust, Coal emission, biomass combustion and road dust, among which motor vehicle exhaust contribution is dominant. (6) the total mass concentration of OC in fine particulate matter in Shanghai atmosphere particles is slightly higher than the total mass concentration in coarse particles in haze season. In December, the IC in atmospheric particulates also had similar distribution characteristics, and IC was in the fine particles. The mass concentration is slightly higher than the total mass concentration in the coarse particles, while the IC in the atmospheric particles in the month of 2,3 has the opposite distribution characteristics, and the total mass concentration of IC in fine particles is slightly lower than the total mass concentration in the coarse particles. In January, the IC in the atmospheric particles in Shanghai city was evenly distributed in the particle sizes, so IC was fine. The total mass concentration in the particles is approximately equal to the total mass concentration in the coarse particles. (7) OC in PM2.5 has a great relationship with the sources of the 6 ions, such as HCOO-, NO_3~-, SO_4~ (2-), BrO_3~-, NH4+ and K+.

【学位授予单位】：上海师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X513

【参考文献】