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为更好地了解碳质组分的特点和来源,在常州市采集了夏季(7~8月)和秋季(10~11月)60个细颗粒物(PM_(2.5))样品.采样期间,夏季PM_(2.5)、OC、EC平均浓度分别为73.0、14.3和3.3μg·m~(-3),秋季为84.2、13.2和3.5μg·m~(-3).总碳质组分(OC+EC)占PM_(2.5)总质量的24.3%(夏季)和20.7%(秋季).采用IMPROVE-A热/光反射法测定的碳质8组分结果表明,OC2、OC3、OC4和EC1相关性好(r>0.92),EC2和EC3相关性较好(r>0.65),说明可能的相似来源.OC与EC相关性中等,表明碳质组分来源复杂.秋季WSOC/OC(60.9%)略高于夏季(57.4%),而夏季SOC/OC(52.5%)略高于秋季(49.0%).夏季和秋季SOC/OC都低于WSOC/OC,说明部分水溶性有机碳是一次源.WSOC和SOC相关性强,进一步验证了大部分SOC具有水溶性.碳质组分之间的关系及主成分分析表明,采样期间燃煤和机动车尾气排放是碳质组分的两个主要来源.后向轨迹分析表明,采样点PM_(2.5)和碳质组分主要受当地排放源和短距离传输的影响,长距离传输贡献较小.
In order to better understand the characteristics and sources of carbonaceous components, 60 fine particulate matter (PM_ (2.5)) were collected in summer (July-August) and autumn (October- The average concentrations of PM, EC and EC were 73.0, 14.3 and 3.3 μg · m -3, respectively, which were 84.2, 13.2 and 3.5 μg · m -3 in autumn, respectively.The total carbon fraction (OC + EC) accounted for 24.3% (summer) and 20.7% (autumn) of the total mass of PM 2.5 (fall) Results of the carbonaceous 8 component using the IMPROVE-A heat / light reflectometry showed that the correlations of OC2, OC3, OC4 and EC1 (R> 0.92), and the correlation between EC2 and EC3 was good (r> 0.65) indicating possible similar sources.The correlation between OC and EC was moderate, indicating that the sources of carbonaceous components were complicated.The WSOC / OC (60.9% (57.4%) in summer, while SOC / OC (52.5%) in summer was slightly higher than that in autumn (49.0%). Both SOC and OC were lower than WSOC / OC in summer and autumn, indicating that some of the water- And SOC, and further verified that most of the SOCs were water-soluble.The relationship between carbonaceous components and principal component analysis indicated that coal and motor vehicle exhaust emission were the two main sources of carbonaceous components during sampling. The backward trajectory analysis shows that the sampling point PM_ (2.5) and the carbonaceous component are mainly affected Impact of emission sources and short-distance transport, long-distance transmission contribution is small.