深圳南头半岛冬季大气中PAHs的分布特征与来源

Distribution characters and source of atmospheric polycyclic aromatic hydrocarbons in Shenzhen Nantou Island

对深圳市南头半岛冬季期间大气中的多环芳烃(PAHs)进行了为期2个月的连续观测.结果表明,PAHs主要以气态化合物为主,其中菲的含量最高,气态和固态PAHs的平均含量分别为99.3,26.4ng/m3.气象条件的变化对大气PAHs影响显著,灰霾期大气中PAHs含量的高值源于无风、干燥气象条件下形成的逆温效应,而降雨可有效去除固态PAHs.采用因子分析与特征化合物比值法对大气中PAHs的来源与贡献率进行了研究,大气中PAHs主要来源为机动车尾气排放、燃煤发电和垃圾焚烧发电,其贡献率分别为50.0%、29.4%和20.6%.

Atmospheric polycyclic aromatic hydrocarbons（PAHs） were weekly monitored for 2 months in Shenzhen Nantou Island during the winter of 2006. The detected PAHs were mainly of vapor phase compounds with phenanthrene dominant. The mean concentration of vapor phase and particulate phase PAHs was 99.3ng/m^3 and 26.4 ng/m3,respectively. Meteorological condition showed great effect on atmospheric PAHs concentration. The higher PAHs level observed during haze weather may result from the accumulation of pollutants under decreased boundary layer,slower wind speed,and long-term dryness conditions. In addition,rainfall significantly clear away particle phase PAHs. The sources of PAHs were drawn by principal factor analysis（PCA） in combination with diagnostic ratios. It is indicated that vehicle exhaust,coal combustion and solid waste incinerator was the major PAHs source,which contributes to 50.0%,29.4% and 20.6% of the total PAHs released,respectively.