节点文献
南京市区郊区大气PM10、PM2.1中PAHs的分布特征及影响因素
Characteristics and influence factors of PAHs in PM10 and PM2.1 in urban and suburban Nanjing, China
【摘要】 2009年11月2010年7月,同步采集了南京市区郊区大气PM10、PM2.1样品,利用气相色谱-质谱联用仪（GC-MS）对其中16种PAHs进行定量分析.结果表明,南京市区、郊区大气PM10中ΣPAHs浓度范围分别为32.84245.35ng/m3、21.43225.72ng/m3.PM2.1中分别为19.11111.57ng/m3、19.69125.21ng/m3,市区和郊区PAHs分布差异不大,均呈现冬季>夏季的季节特征.PM10、PM2.1中PAHs均以4、5、6环为主,占总质量浓度的78.7%83.1%(PM10)、80.5%87.1%(PM2.1),冬季4环PAHs的比例明显增加.市区和郊区PAHs浓度昼夜变化趋势不同,即市区白天大于夜间,而郊区夜间大于白天.在所测定的气象条件中,温度、相对湿度和PM10浓度对PAHs影响显著,温度、相对湿度对PAHs的贡献为负,而PM10对PAHs贡献为正,暖季（夏秋）PAHs受到气象条件的影响大于冷季（冬春）,O3对5、6环PAHs表现出显著的负贡献.利用后向轨迹分析发现南京受到本地排放和周边地区污染源的影响,来自南京东南和西南方向的短距离输送气团对PAHs浓度上升影响较大.
【Abstract】 PM2.1 and PM10 samples were synchronously collected at suburban and urban sites in Nanjing,16 kinds of PAHs were analyzed by the GC-MS.The concentrations of total PAHs at the urban and suburban were in the ranges of32.84-245.35ng/m3 and 21.43225.72ng/m3 for PM10,respectively,and 19.11111.57ng/m3 and 19.69125.21ng/m3 for PM2.1.PAHs concentrations at the two sites were close to each other,and show similar seasonal variation with the winter concentrations larger than those in the summer.PAHs mainly compose of 4-,5- and 6-ring PAHs that have mass fractions（to total PAH mass） of 78.7%83.1%in PM10 and 80.5%87.1%in PM2.1,and the fraction of 4-rings PAHs in winter was clearly larger than those of other seasons.The PAHs at two sites showed different diurnal variations.At the urban site,the concentration in the daytime was higher than that in the nighttime,whereas values in the nighttime become larger at the suburban site.Among the various meteorological parameters,the PAH concentration shows clearly negative correlations to both temperature and relative humidity,and a positive correlation is noticed between the PM10 and PAHs.The influence of meteorological parameters was more significant in warm seasons（summer and autumn） than that in cold seasons（winter and spring）.Ozone concentration also had a negative correlation to the 5- and 6-ring PAHs concentration.The results from air mass back-trajectory model show that the accumulation of PAHs was mainly influenced by local emission,and polluted airs from southwest and southeast of Nanjing are also an important source of the PAHs through shout-range transport.
【Key words】 PAHs； PM10； PM2.1； seasonal variation； diurnal and nocturnal variation； meteorology；
- 【文献出处】 中国环境科学 ,China Environmental Science , 编辑部邮箱 ,2017年01期
- 【分类号】X513
- 【被引频次】12
- 【下载频次】276