宁波和温州地区夏季大气中不同粒径颗粒物特征分析

对宁波地区北仑和奉化站、温州地区乐清站3个监测点夏季TSP、PM10、PM2.5和PM1.0进行监测,测试分析各种粒径颗粒物浓度水平和粒径分布特征,并通过化学质量平衡(CMB)受体模型对颗粒物进行源解析。监测结果显示,夏季宁波、温州地区TSP和PM10日均浓度为0.049～0.134mg/m3和0.025～0.084mg/m3,均未超过我国环境空气质量二级标准;PM2.5日均浓度为0.007～0.069mg/m3,按美国2006年EPA最新标准限值0.035mg/m3衡量,奉化、乐清、北仑站的超标天数占总监测天数的比例分别为75%、40%和37.5%。粒径分布统计结果显示,3个监测站点PM10占TSP的比例为48.78%～86.96%;PM2.5占TSP的比例为33.33%～72.46%;奉化和乐清监测点PM10中PM2.5和PM1.0的比例平均值在50%以上。源解析结果显示,夏季TSP主要来源于土壤尘,其次是建筑尘和煤烟尘,其贡献率分别为40.70%～55.49%、9.62%～13.64%和5.85%～17.28%。

Analysis on Characteristic of Different Size Particulate Matter in Atmospheric Environment of Ningbo and Wenzhou in Summer

TSP,PM10,PM2.5 and PM1.0 were monitored at Beilun,Fenghua and Yueqing monitoring stations during summertime in order to find out the concentration and particle size distribution and the Chemical Mass Balance(CMB) Model was used for source identification and apportionment of TSP.The monitoring results indicated that the daily average concentration of TSP and PM10 were 0.049~0.134mg/m3 and 0.025~0.084 mg/m3 which didn’t exceed the Grade II national standards for air quality and the PM2.5 concentration was 0.007~0.069mg/m3.There are 75%、40% and 37.5% of the monitoring days that the PM2.5 concentrations exceeded the latest standard value(0.035 mg/m3) of USEPA in 2006 respectively in Fenghua,Yueqing,Beilun station.The statistic result of the particle size distribution has shown that PM10/TSP and PM2.5/TSP were 48.78%~86.96% and 33.33%~72.46% and at Fenghua and Yueqing station PM2.5/PM10 and PM1.0/PM10 were more than 50%.Ambient and source data were used in the CMB model for source identification and apportionment,indicating that major sources of TSP in Ningbo and Wenzhou City were soil dust(40.70%~55.49%),building dusts(9.62%~13.64%) and coal combustion(5.85%~17.28%).