江苏沿江城市PM_(10)和PM_(2.5)中水溶性离子特征及来源分析

Characteristics and sources analysis of water-soluble ions in PM_(10) and PM_(2.5) in cities along the Yangtze River of Jiangsu Province

2012年3月和6月在江苏沿江七市(镇江、常州、无锡、苏州、扬州、泰州和南通)采集空气中PM10和PM2.5样品,运用离子色谱法,分析无机水溶性离子成分,并对其组成、相关性、结合形式和来源解析等方面进行研究.结果表明,春季苏南四市PM10和PM2.5质量浓度低于苏中三市,夏季反之;水溶性离子在PM2.5中所占的比例一般高于PM10,SO2-4、NO-3、NH+4是颗粒物中水溶性离子的主要成分,占总量的80%左右.PM10和PM2.5中的SO2-4和NO-3、NH+4和SO2-4、NO-3之间均具有较好的相关性;PM10中Ca2+和Mg2+显著相关,细粒子中相关性较小.NH+4和SO2-4、NO-3主要以(NH4)2SO4和NH4NO3存在于可吸入颗粒物中.春夏两季,江苏沿江城市PM10和PM2.5中的SOR均大于NOR,SO2在大气中的转化率比NOx的转化率要高;苏南地区PM10和PM2.5中的SOR和NOR高于苏中地区.运用[NO-3]/[SO2-4]的比值法研究颗粒物污染来源,表明春季的污染源主要为流动源,夏季为固定源.运用因子分析法分析颗粒物来源,燃煤、交通运输、生物质燃烧、土壤和建筑地表扬尘是春夏两季江苏沿江城市可吸入颗粒物的主要污染源.

Atmospheric PM10 and PM2.5 samples were collected from seven cities（ Zhenjiang,Changzhou,Wuxi,Suzhou,Yangzhou,Taizhou and Nantong） along the Yangtze River in Jiangsu Province in March and June,2012. Ion chromatography was used to aralyze the composition correlation,speciation and sources of inorganic water-soluble ions. The results indicate that the concentrations of PM10 and PM2. 5in the four cities of southern of Jiangsu（ SJ） were lower than those in three cities in central Jiangsu（ CJ） during the spring. However,opposite results were observed in the summer; The proportion of water-soluble ions in PM2. 5was generally higher than the proportion in PM10. SO4^2-,NO3^-,NH4^＋were the main components of particulate water-soluble ions,contributing to around 80% of the total. Among all PM10 and PM2. 5samples,SO4^2-showed good correlation with NO3^-,so did NH＋4with SO4^2-and NO3^-. Ca^2＋and Mg^2＋were significantly related with each other in PM10,but low correlation was found in the fine particles. NH＋4,SO4^2-and NO3^-mainly exist as（ NH4）2SO4and NH4NO3 in the inhalable particulate. The SOR of PM10 and PM2. 5was higher than the NOR both in the spring and summer,the conversion rate of SO2 was higher than NOxin theatmosphere. SOR and NOR in SJ were higher than those in CJ. The results from actor analysis revealed that transportation,biomass burning,soil and building surface dust were the main sources of inhalable particles pollution along the Yangtze River City.