西安建筑科技大学硕士学位论文 西安市典型时段 PM2.5中碳组分高分辨率污染特征 及气象影响分析 专 业：环境环境科学科学 硕 士 生：王王 炜炜 指导教师：张承中张承中 教授教授 摘 要 近年来，西安城市空气环境质量逐年下降，灰霾事件多发，PM2.5受到更多人的关注PM2.5粒径微小，易通过呼吸进入肺部，可对人类健康造成严重的危害本文在 2009.11～2012.12 开展了针对 PM2.5的观测实验研究， 系统的获得西安市南郊大气中 PM2.5高分辨率下的时间序列分布特征在此基础上，采集了冬季典型时段（Ⅰ.春节期间、Ⅱ.晴好天气、Ⅲ.沙尘过程）的 PM2.5高分辨率下的时间序列分布样品，探讨了碳组分的实时变化特征、天气条件对气溶胶的影响、细尺度下大气碳气溶胶变化过程，分析了气象因子对 PM2.5及其碳组分的影响 监测期西安市三年 PM2.5年均浓度分别为 73.470±55.357μg/m3、 107.208±75.626 μg/m3、110.010±77.449μg/m3对比国家二级标准，三年年均浓度均超标，超标倍数分别为 2.10，3.06，3.14进一步分析三年 PM2.5四季浓度日均分布，各季节浓度超过二级（75µg/m3）标准限值所占比率为：冬季（64.09%）＞秋季（62.40%）＞春季（50.05%）＞夏季（38.00%） 。
四个季节 PM2.5的浓度都在逐年上升三年采暖期 PM2.5日均浓度分别 108.605±75.893μg/m3、112.217±84.354 μg/m3、146.160±94.550 μg/m3 三年采暖期 PM2.5日均浓度均超过二级标准的阀值， 超标情况为：2010 年超标 1.45 倍，2011 年超标率 1.50 倍，2012 年超标率 1.90 倍说明西安市 PM2.5污染的总体趋势还在逐渐加重 采样期西安市 OC、EC 和 WSOC 浓度均值分别为 48.651 μg/m3，12.921 μg/m3和 19.900 μg/m3，三种组分浓度均值在三时段内分布有所差异：OC 和 WSOC 呈>>Ⅱ Ⅰ Ⅲ变化趋势，EC 呈>>Ⅰ Ⅱ Ⅲ变化三种组分日分布在各时段存在差异，其中 EC 分布较为稳定， 在三时段皆呈早晚双峰分布， 表明在冬季 EC 来源相对稳定，主要源于燃煤的排放；OC 在Ⅰ时段和Ⅲ时段与 EC 变化类似，说明此时二者有相同的源， Ⅱ时段 OC 呈昼高夜低分布特征， 表明该时段因白天光化学反应强烈而生成二次有机碳WSOC 和 WSOC/OC 的变化与 OC 相同，外来传输源对碳组分有西安建筑科技大学硕士学位论文 一定影响。
三种组分相关关系表明冬季 OC、EC 来源相同，主要源于燃煤和汽车尾气，WSOC 与 OC 相关性良好，与 EC 相关性最低，表明 WSOC 多为二次生成的有机物冬季采用 OC/EC 最小值法估算 SOC 浓度均值为 20.164μg/m3，占 OC的比例为 36.549%，SOC 浓度分布在三时段呈>>Ⅱ Ⅰ Ⅲ变化同时采样期 SOC 浓度白天 22.548 μg/m3，高于夜间 17.718 μg/m3，表明冬季晴天有利于光化学反应的发生而形成 SOC，SOC 是大气有机物的重要组成部分 PM2.5和其碳组分与气象因子的相关关系存在差异，说明气象因素对 PM2.5的影响复杂西安地处谷地，低空大气流动缓慢，垂直气流和湍流活动较弱，大气层结稳定度高， 混合层高度较低， 大气扩散能力较弱， 成为 PM2.5污染物堆积之地地理地形造成西安特殊的气象条件，不利于颗粒物扩散，易形成灰霾天气因此控制西安 PM2.5污染应主要针对人为源 关键词关键词：PM2.5；典型时段；高分辨率；碳组分；气象因素 西安建筑科技大学硕士学位论文 High-resolution pollution characteristics and weather impact analysis of carbon fractions in PM2.5 at typical period in Xi'an Major: Environmental Science Author: Wang Wei Instructor: Professor.Zhang Chengzhong Abstract With the recent decline in air quality, haze event multiple more concern about PM2.5 ,it particle size small to easily enter the lungs through breathing and cause serious harm to human health. In this study, the observed experimental study for PM2.5 carried out in 2009.11～2012.12, high resolution system distribution sequence ambient PM2.5 in Xi'an. On this basis, the high-resolution acquisition of a typical winter period (during the Spring Festival, the fine weather, dust process) of PM2.5 samples, explores the real-time variation of the carbon component, the impact of weather conditions on aerosol, fine scale atmospheric carbon aerosol processes, the use of mathematical and statistical methods to source apportionment of PM2.5 and its carbon component, analysis of meteorological factors on PM2.5 pollution. The monitoring period of three years PM2.5 daily average concentration respectively to 73.470±55.357,107.208±75.626 and 110.010±77.449μg/m3 in Xi'an. Contrast to the national standard, the three-year average daily concentrations exceeded superscalar multiples were 2.10, 3.06, 3.14. Four Seasons concentration distribution of further analysis of the three PM2.5 the concentration of more than two of each season (75μg/m3) the standard limit percentage as follows: winter(64.09%)>autumn(62.40%)> spring(50.05%)>summer(38.00%). The four seasons of PM2.5 concentrations are increasing every year. PM2.5 daily average concentration of the three-year heating period were 108.605 ± 75.893, 112.217 ± 84.354, 146.160 ± 94.550 μg/m3. Three winter PM2.5 daily average concentration of over one standard threshold exceedances: 1.45,1.50， 1.95 from 2010 to 2012. PM2.5 pollution overall trend is gradually increased in Xi'an. Sampling period OC,EC and WSOC concentration mean 48.651 μg/m3, 12.921μg/m3 and 19.900 μg/m3 in Xi'an, the three components of the average 西安建筑科技大学硕士学位论文 concentration distribution in the three periods differ: OC and WSOC was >>Ⅱ Ⅰ Ⅲ , EC was>>Ⅰ Ⅱ Ⅲ . On three components distributed in each period there are differences, which the EC distribution is more stable, sooner or later, in three periods exhibited a bimodal distribution, indicating relatively stable in the winter EC sources, mainly from coal-fired emissions; OCperiod and III period the EC changes similar, this time the Ⅰtwo have the same source, period OC was circadian distribution, indicating that the Ⅱperiod due to the strong the Bai Tianguang chemical reaction and generate secondary organic carbon. WSOC and WSOC/OC changes with OC，the alien transmission source of the carbon fractions. The relationship of the three components that winter OC, EC sources, mainly from the coal and automobile exhaust, of WSOC and OC good correlation with EC lowest correlation WSOC more secondary organics. Winter OC/EC minimum value method to estimate mean SOC concentration 20.164μg/m3, accounting for 36.549% proportion of OC the SOC concentration distribution in the three periods was >Ⅱ Ⅰ> changes simultaneous sampling ofⅢ SOC concentration daytime 22.548 μg/m3 much higher than 17.718 μg/m3 in nighttime, and that winter Clear conducive to the occurrence of photochemical reactions。