夏季珠江三角洲地区PM2.5化学组分特征及其对大气能见度的影响

Chemical Compositions in PM_(2.5) and Its Impact on Visibility in Summer in Pearl River Delta,China

于2010年夏季在珠三角主要城市广州、佛山、东莞、深圳、珠海以及广州郊区从化同步采集PM2.5样品,利用热光反射碳分析仪和离子色谱分别分析样品中有机碳/元素碳和水溶性离子浓度,并同步收集能见度和气象数据.在此基础上对珠三角主要城市大气PM2.5中主要化学成分的浓度水平和空间分布特征进行分析,并利用IMPROVE方程重建大气消光系数,探讨PM2.5的主要化学组分对大气能见度的影响.结果发现,观测期间珠三角地区PM2.5中的主要化学成分空间分布特征明显,广州、佛山和东莞浓度较高,珠海和深圳浓度较低.(NH4)2SO4、有机物(OM)、EC和NH4NO3对夏季珠三角大气消光系数贡献率分别为39%、31%、12%和13%.

Aerosol samples of PM2. 5were collected simultaneously at 6 sites from five cities( Guangzhou urban,Conghua( suburban of Guangzhou),Foshan,Dongguan,Shenzhen and Zhuhai) in Pearl River Delta region during the summer of 2010. The concentrations of organic carbon( OC),elemental carbon( EC) and water-soluble ions were determined by thermal / optical carbon analyzer and ion chromatography,respectively. The characteristics of PM2. 5,OC,EC and ions,spatial distribution were discussed. Moreover,ambient light extinction coefficients were reconstructed by IMPROVE formula. The results showed that spatial distribution characteristics of PM2. 5and its chemical compositions were obviously different. The PM2. 5in Guangzhou,Foshan and Dongguan were higher than those in Zhuhai and Shenzhen. The contributions of( NH4)2SO4,OM,EC and NH4NO3 to ambient light extinction coefficient were 39%,31%,12% and 13%,respectively.