天津近岸海域大气颗粒物无机组分季节变化及源析

2006~2007年在天津近岸海域分4个季节走航采集了不同粒径大气颗粒物样品,分析了其质量浓度以及元素、离子和碳等化学组成,并应用富集因子以及特征化合物比值对其来源进行了探讨.结果表明,天津近岸海域TSP,PM10和PM2.5的质量浓度分别为(294.98±3.95),(279.87±17.53),(205.50±38.13)μg/m3,且呈现出明显的季节变化,秋季颗粒物浓度最高,冬季次之,夏季最低. TSP、PM10和PM2.5中总元素浓度分别为48.76, 47.94,32.08 μg/m3. TSP中含量最高的离子是Na+, PM10和PM2.5中含量最高的离子是Cl-. 3种不同粒径中OC浓度秋、冬两季均明显高于春夏两季. Al/Fe的比值分析结果表明,春季TSP的主要来源为土壤尘,秋、冬季PM10和PM2.5主要受燃煤的影响. Cu、Zn和Pb的富集系数较高,其中Pb在冬季PM10中富集达到最高为741.3. NO3-/SO42-的变化范围为0.28~0.85,春夏季该比值较高于秋冬季,反映了该海域同时受燃煤与机动车污染的影响.OC/EC变化范围为2.13~5.58,表明该海域气溶胶中存在着大量二次有机碳.

Seasonal variation of inorganic composition in ambient particulate matter in Tianjin offshore area and its source analysis

Atmospheric particulate matter with different diameters (TSP, PM10and PM2.5) were collected during four cruises in Tianjin offshore area in 2006~2007 to analyze mass concentrations, main chemical components including elements, ions and carbon. The sources were analyzed using enrichment factors and ratios. The mass concentrations of TSP, PM10and PM2.5 were (294.98±3.95), (279.87±17.53) and (205.50±38.13)μg/m3, respectively and they represented obviously seasonal variation, with the highest value in autumn, then coming winter and the lowest in summer. The total element concentrations were 48.75, 47.94 and 32.08μg/m3 in TSP, PM10 and PM2.5. The highest ion was Na+ for TSP. The richest ion was Cl- for PM10and for PM2.5. The concentrations of OC for PM were all higher in autumn and winter than in spring and summer. The main source was soil for TSP in spring, but coal combustion translation particles influenced most for PM10and PM2.5in autumn and winter according to the Al/Fe value. Higher EFc values for Cu、Zn and Pb were found with the highest value 741.3 for Pb in PM10in winter. NO3-/SO42- ranged from 0.28to 0.85, with higher values in spring and summer than autumn and winter, which indicated that coal combustion and vehicle emission were both main sources. The variation range of OC/EC in 2.13~5.58indicated the existence of secondary organic carbon in this region.