邯郸市PM_(2.5)成分的时空分布特征及来源

Spatial and temporal distribution and source analysis of components in PM_(2.5),Handan

为了解河北省邯郸市PM_(2.5)污染的时空分布特征,于2015年1、4、7、10月在邯郸市环保局(HBJ,商业交通居民混合区)、东污水处理厂(DWS,一般工业区)、矿院(KY,文化区)和丛台公园(CT,城市绿地)等4个国控站进行PM_(2.5)样品采集,并测定样品中的25种化学成分(NH_4^+、Na^+、K^+、Mg^(2+)、Ca^(2+)、SO_4^(2-)、Cl^-、NO_3^-、OC、EC、Na、Mg、Al、K、Ca、Ti、V、Cr、Mn、Fe、Co、Cu、Zn、Ba、Pb).结果表明,DWS和HBJ的PM_(2.5)浓度相对其他站点更加严重,CT污染最轻;1月站点之间差异性较大.除Ca^(2+)外,1月PM_(2.5)中其余化学组分浓度均明显高于其他月份.二次水溶性无机离子(SNA)空间分布表现为1月DWS、4月CT、7和10月HBJ污染严重,KY最轻;KY元素碳高于其他站点;无机元素站点差异性不大.主成分分析结果表明,二次气溶胶源、部分交通源、化石燃料和生物质燃烧源是PM_(2.5)的主要来源,其次是土壤和建筑尘以及钢铁工业等.后向轨迹模型模拟结果表明,4个月来自山西、河南、山东、河北境内的短轨迹数占比分别达到50%、27%、74%和50%,说明7月受区域污染的可能性较大;而1、4、10月经远距离输送的污染物易形成二次污染物,对邯郸空气污染产生影响.

To understand the temporal and spatial distribution of fine particulate matter （ PM2.5 ） in Handan, PM2.5 samples were collected in January, April, July and October 2015 at four sampling sites, including the municipal environmental protection bureau （HBJ, a mixed-use area of commercial and traffic and residential compounds ）, East sewage treatment plant （DWS, an industrial district）, Hebei University of Engineering （KY, a culture region ） and CongTai park （CT, urban green land） in Handan and twenty-five chemical components of PM2.5 were analyzed. The results indicated that PM2.5 levels at DWS and HBJ were higher than other sampling sites, and the PM2.5 concentration at CT was the lowest. The differences among the four sampling sites in January were larger than other months. Except Ca2＋, the chemical components in January were significantly higher than other months. The spatial distribution of SNA showed that the PM2.5 concentration DWS in January and at CT in April and HBJ in July and October were the highest. In all months, the carbon content of KY was the lowest. Besides, there was no difference in the metal content between the four sites. The results of principal component analysis showed that the secondary aerosol source, transportation, fossil fuel and biomass burning source were the main sources of PM2.5, followed by soil and construction dust and steel industry. HYSPLIT Trajectory Model was used to simulate the chemical transport, and the short trajectories in four months accounted for 50%, 27%, 74%, 50%, respectively. This shows the possibility that regional sources contribute more to PM2.5 pollution in July; but in January, April and October, pollutants through long-distance transport transformed easily into secondary pollutants to produce severe PM2.5 pollution.