OC/EC ratio observations in Europe: Re-thinking the approach for apportionment between primary and secondary organic carbon
OC/EC ratio observations in Europe: Re-thinking the approach for apportionment between primary and secondary organic carbon
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DOI：
10.1016/j.atmosenv.2011.08.045
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发表时间：
2011-11-01
影响因子：
5
通讯作者：
Matos, Manuel
中科院分区：
文献类型：
--
作者：
Pio, Casimiro;Cerqueira, Mario;Matos, Manuel
本研究探讨了一个大的OC和EC测量PM10和PM2.5气溶胶样品，进行了长期恒定的分析方法，以评估OC/EC的最小比率的能力，以代表OC和EC气溶胶成分之间的比例从化石燃料燃烧（OCff/ECff）。该数据集涵盖欧洲广泛的地理区域，但特别侧重于葡萄牙、西班牙和联合王国，包括各种各样的地点：城市（背景、路边和隧道）、工业、农村和偏远地区。最高的最低比率出现在偏远和农村地区的样本中。结果表明，该方法可用于计算化石燃料燃烧产生的有机碳与挥发性有机碳的比值，从而区分有机碳的一次源和二次源。为了探索这种能力，OC和EC测量进行了在忙碌巷道隧道在中央里斯本。反映车辆燃烧排放物组成的OC/EC比率在0.3 -0.4之间。英国伯明翰路边增量空气（路边减去城市背景）中的OC/EC比值也在0.3 -0.4之间。在交通繁忙的情况下，在位于里斯本和马德里中心的两个双路边站点进行了额外的测量。在这两个网站观察到的OC/EC的最低比率被发现之间的隧道和城市背景空气，这表明，通常在开放的城市大气中获得的最低值为这个参数预测的直接排放的OCFF从道路运输。这种差异的可能原因进行了探讨。(C)2011爱思唯尔有限公司保留所有权利。
This study explores a large set of OC and EC measurements in PM10 and PM2.5 aerosol samples, undertaken with a long term constant analytical methodology, to evaluate the capability of the OC/EC minimum ratio to represent the ratio between the OC and EC aerosol components resulting from fossil fuel combustion (OCff/ECff). The data set covers a wide geographical area in Europe, but with a particular focus upon Portugal, Spain and the United Kingdom, and includes a great variety of sites: urban (background, kerbside and tunnel), industrial, rural and remote. The highest minimum ratios were found in samples from remote and rural sites. Urban background sites have shown spatially and temporally consistent minimum ratios, of around 1.0 for PM10 and 0.7 for PM2.5.The consistency of results has suggested that the method could be used as a tool to derive the ratio between OC and EC from fossil fuel combustion and consequently to differentiate OC from primary and secondary sources. To explore this capability, OC and EC measurements were performed in a busy roadway tunnel in central Lisbon. The OC/EC ratio, which reflected the composition of vehicle combustion emissions, was in the range of 03-0.4. Ratios of OC/EC in roadside increment air (roadside minus urban background) in Birmingham, UK also lie within the range 03-0.4. Additional measurements were performed under heavy traffic conditions at two double kerbside sites located in the centre of Lisbon and Madrid. The OC/EC minimum ratios observed at both sites were found to be between those of the tunnel and those of urban background air, suggesting that minimum values commonly obtained for this parameter in open urban atmospheres over-predict the direct emissions of OCff from road transport. Possible reasons for this discrepancy are explored. (C) 2011 Elsevier Ltd. All rights reserved.