Variability of organic and elemental carbon, water soluble organic carbon, and isotopes in Hong Kong
Variability of organic and elemental carbon, water soluble organic carbon, and isotopes in Hong Kong
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DOI：
10.5194/acp-6-4569-2006
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发表时间：
2006-10-12
影响因子：
6.3
通讯作者：
Fung, K.
中科院分区：
文献类型：
--
作者：
Ho, K. F.;Lee, S. C.;Fung, K.
为了确定香港含碳气溶胶的水平和变化，在冬季（2000年11月至2001年2月）和夏季（2001年6月至2001年8月）期间，在三个监测站（代表中等规模的路边、城市和区域环境）使用高容量（Hi-vol）采样器采集了PM2.5和PM10样品。有机碳（OC），元素碳（EC）和水溶性有机碳（WSOC）的浓度最高的被发现在中等规模的路边站点与区域尺度的网站最低。在这些地点，WSOC在总碳中的百分比与其浓度呈负相关（即，在区域尺度的站点观察到WSOC的最高百分比）。一个高的WSOC部分可能与老化的气溶胶，因为在运输过程中的人为污染物的有机前体的光化学氧化的二次形成。OC和EC的年平均同位素丰度（δ C-13）分别为-26.9 +/-0.5ppm和-25.6 +/-0.1ppm。碳同位素组成的季节性分布没有显著差异，与汽车排放物是香港含碳气溶胶的主要来源一致。OC C-13丰度在区域尺度的网站高于那些在中等规模的路边和城市网站，符合二次有机气溶胶的生物起源。
To determine the levels and variations of carbonaceous aerosol in Hong Kong, PM2.5 and PM10 samples were collected by high volume (Hi-vol) samplers at three monitoring stations ( representing middle-scale roadside, urban-, and regional-scale environments) during winter ( November 2000 to February 2001) and summer ( June 2001 to August 2001) periods. The highest concentrations of organic carbon (OC), elemental carbon (EC), and water-soluble organic carbon (WSOC) were found at the middle-scale roadside site with the lowest at the regional-scale site. The percentages of WSOC in total carbon at these sites were inversely correlated with their concentrations (i.e., the highest percentages of WSOC were observed at the regional-scale site). A high WSOC fraction may be associated with aged aerosol because of the secondary formation by photochemical oxidation of organic precursors of anthropogenic pollutants during transport. The annual average of isotope abundances (delta C-13) of OC and EC were - 26.9 +/- 0.5 parts per thousand and - 25.6 +/- 0.1 parts per thousand, respectively. There were no notable differences for seasonal distributions of carbon isotopic composition, consistent with motor vehicle emissions being the main source contributors of carbonaceous aerosol in Hong Kong. OC C-13 abundances at the regional-scale site were higher than those at the middle-scale roadside and urban sites, consistent with secondary organic aerosols of biogenic origin.