北京市昌平地区2014年冬季颗粒物PM2.5中典型污染物分析

Analysis of typical pollutants in air fine particulate matter PM2.5 in Changping district of Beijing during the winter of 2014

目的分析昌平地区冬季大气细颗粒物(PM2.5)污染特征,为北京市大气污染相关研究提供科学数据。方法于2014年冬季(10月、11月、12月)在北京市昌平区采集PM2.5样品,并分析样品中的典型污染物——16种多环芳香烃(PAHs)和12种微量元素的浓度水平及污染特征。结果昌平地区PM2.5的质量浓度为17.5μg/m^3~403μg/m^3,日平均浓度为130.9μg/m^3,超过最新环境空气质量标准制定的PM2.5日平均浓度限值(75μg/m^3);PM2.5中PAHs总浓度变化为0.57 ng/m^3~58.5 ng/m^3,且PAHs主要以3环、4环、5环、6环存在,其中4环和5环PAHs含量最高,分别占总量的46.34%和31.57%;PM2.5中的重金属元素的质量浓度为0.394 ng/m^3~398 ng/m^3。结论燃煤和机动车尾气是昌平区冬季大气颗粒物PM2.5中PAHs的主要来源;人为污染是昌平区冬季PM2.5中元素污染的主要来源;PM2.5浓度与相对湿度呈正相关,而与风速呈负相关。

Objective To analyse the pollutant characteristics of PM2. 5 in Changping district of Beijing,so as to provide scientific reference for the research on the air pollution of Beijing. Methods Air PM2. 5 samples were collected during winter（ October,November and December） of 2014,the concentration levels as well as pollutant characteristics of 12 trace elements and 16 polycyclic aromatic hydrocarbons（ PAHs） were analyzed. Results The concentration of PM2. 5 was among 17. 5 μg / m3-403 μg / m^3 with the daily average concentration of 130. 9 μg / m3,which was over the national ambient air quality standards of75 μg / m3; the concentration of PAHs was among 0. 57 ng/m3- 58. 5 ng / m3,with which the PAHs mainly existed in the 3rd,4th,5th,6thloop,and among them the PAHs were the most in the 4th and the 5th loop,accounting for 46. 34% and 31. 57%,respectively; the concentration of heavy metal elements was among 0. 394 ng / m3- 398 ng / m3. Conclusion Emissions from coal and motor vehicles are the main sources of PAHs in winter atmospheric particulate matter PM2. 5 in Changping district,and human pollution is the main source of PM2. 5 pollution in winter in Changping district; the concentration of PM2. 5 was positively correlated with relative humidity,and has negative correlation with wind speed.