鄱阳湖生态经济区城市大气颗粒物中PAHs分布特征及来源

摘要

To understand the sources of the polycyclic-aromatic hydrocarbons(PAHs)in atmospheric particles and to explore their seasonal and annual changing trends in representative cities of the Poyang Lake Ecological Economic Zone,atmospheric samples were collected in Nanchang and Jiujiang cities during winter and summer in 2015.14PAHs from the air were analyzed by ultrasonic extraction-HPLC.The results showed that the concentrations of PAHs in Nanchang and Jiujiang were relatively low.The PAHs in PM2. 5of the air composed mainly of high-ring components,where the 4-ring component has the largest percentage. In terms of the regional distribution,the concentrations of PAHs in Nanchang were about twice those of Jiujiang.Concentrations ofΣPAHs showed great seasonal and annual variation.Concentrations of PAHs in winter were greater than those in summer.Concentrations of PAHs in 2015were greater than those in 2008.According to the ratio method,the PAHs in Poyang ecological economic zone were mainly from the coal combustion and the traffic fuels.The coal combustion was the main source of PAHs in winter,and the coal combustion was the main source of PAHs in summer.%为了解鄱阳湖生态经济区典型城市大气颗粒物PAHs的季节性、年际变化趋势和来源,采集了2015年冬季和夏季鄱阳湖生态经济区典型城市(南昌、九江)大气样品,采取超声波萃取-高效液相色谱法(HPLC)分析测定样品中14种PAHs.研究结果显示,鄱阳湖生态经济区南昌、九江市大气中PAHs浓度总体处于较低水平,大气颗粒物中PAHs主要以高环组分存在,4环组分占比最多.从区域分布来看,南昌市PAHs浓度高于九江市.Σ PAHs浓度呈现出冬季高于夏季的季节性变化特征,并有逐年增长趋势.比值法分析结果显示鄱阳湖生态经济区内PAHs的主要来源为燃煤和交通燃料,其中燃煤在冬季占比较大,交通燃料在夏季占比较大.