乌鲁木齐市大气细颗粒物（PM2．5）污染成分特征

摘要

目的：分析研究乌鲁木齐市2014－2015年空气大气细颗粒物（PM2．5）样品中主要的重金属和离子的浓度及分布特征。方法利用智能大流量PM2．5空气颗粒物采样器采集61个大气细颗粒物样品，对其主要的重金属和阴离子浓度的分布特征进行研究分析。结果所采集的样品中 PM2．5超标率高达100％，且采暖期 PM2．5浓度高于非采暖期。成分分析发现 Na、K、Mg、Ca、Pb、Zn、Fe 和 Cu 是 PM2．5中主要的重金属污染物，其中 Na、Mg、Ca、Zn、Fe 5种重金属相对比较固定，且所占比例最高，占总成分的90％以上。非采暖期这5种重金属污染浓度依次为Ca＞Fe＞Zn＞Mg＞Na；采暖期为 Ca＞Zn＞Fe＞Na＞Mg。PM2．5中的主要阴离子为 F－、Cl－、NO－3和SO2－4。在不同月份检测的细颗粒物阴离子中，不同阴离子所占比例相对比较稳定，且均为 SO2－4＞NO－3＞Cl－＞F－。结论乌鲁木齐市大气污染浓度较高，大气中 PM2．5超标严重。污染来源主要与交通尾气排放和含硫燃煤的燃烧有关，应加强大气中PM2．5污染的治理。%Objective To investigate the space distribution features of major heavy metals and ions as well as their concentration in atmospheric fine particles (PM2.5 )by collecting samples of atmospheric fine parti-cles (PM2.5 )in Urumqi from 2014 to 2015.Methods 63 atmospheric fine particle samples were collected by using TH-1000CII type intelligent flow PM2.5 particulate air sampler.Results Firstly,among the sam-ples of atmospheric fine particles (PM2.5 ),the over standard rate reaches 100%.Secondly,the concentra-tions of the atmospheric fine particles (PM2.5 )was higher in heating period than that in non-heating period. Thirdly,the results showed that Na,K,Mg,Ca,Pb,Zn,Fe and Cu are the main pollution elements of PM2.5 .Among those mental pollutants,Na,Mg,Ca,Zn and Fe were relatively fixed and they had the highest proportion which reached 90% of all.Fourthly,the differences of the season and the heating supply decided their proportion.For example,in non-heating period:Ca>Fe>Zn>Mg>Na;in heating period:Ca>Zn>Fe>Na>Mg.Fifthly,F-,Cl-,NO-3 and SO2-4 are the main anions in PM2.5 .By testing them in different months,we got the result that the proportion of different anions are relatively fixed and they were shown like this:SO2-4 >NO-3 >Cl->F-.Conclusion Within the atmosphere of Urumqi city, the pollution concentration was in a high level andthe atmosphric fine particles(PM2.5 )was over the limit badly.The source of air pollution was mainly related to the traffic emission and the burning of sulfur fuel. Therefore,we must take measures against the air pollution of atmospheric fine particles(PM2.5 )and im-prove the air quality of Urumqi.