宜昌市城区典型灰霾日PM2．5污染特征研究

对2013年白龙岗站点自动监测数据和手工采集的 PM 2．5中水溶性阴离子进行了分析，结果表明：宜昌市城区灰霾发生频率较高，PM2．5为首要污染物，冬季灰霾天数和PM2．5月均值最高，夏季最低；在典型灰霾日，PM2．5、PM10、SO2和NO2具有相同的变化趋势，在污染物排放总量不改变的情况下，短暂降雨难以从本质上改变灰霾状态；NO3-和SO2-4是PM2．5中的主要水溶性离子，其灰霾日的质量浓度高于非灰霾日，工业区高于商业区；灰霾日NO3-/SO2-4的比值大于非灰霾日，机动车尾气对灰霾的形成影响较大。

Study of Pollution Characteristics of PM2 .5 during Smog Period in Yichang,Hubei Province

This article analyzes the data from air quality automation monitoring system in Bai Longgang and water soluble ions in PM2 .5 by manual samplingin 2013 .The results indicate that smogappears frequently in Yichang City ,and PM2 .5 is its primary pollutants ;the smog frequency and PM 2 .5 value in winter are maxi-mum ,while in summer are minimum ;PM2 .5 ,PM10 ,SO2 and NO2 have the same variation trend ;if total pol-lutant emissions are unchanged ,smog can not beeliminated by short rains ;NO3 - and SO42 -are the main water soluble ions ,both of which concentration in smog daysare higher than in non -smog days ,and inindus-trial zoneare higher than in commercial district ;NO3 -/SO42 -in smog days is also higher in non -smog days ;the off gases of motor vehicles have important influences on the smog formation .