Temporal and spatial distribution of PM2.5 chemical composition in a coastal city of Southeast China
Temporal and spatial distribution of PM2.5 chemical composition in a coastal city of Southeast China
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DOI：
10.1016/j.scitotenv.2017.03.260
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发表时间：
2017-12-15
影响因子：
9.8
通讯作者：
Guo, Song
中科院分区：
文献类型：
--
作者：
Li, Mengren;Hu, Min;Guo, Song
中国快速的经济发展和城市化集中在沿海城市，导致雾霾和光化学烟雾问题，特别是在人口稠密的长江三角洲地区。在本研究中，我们探讨了浙江省（宁波）一座城市的颗粒物（特别是 PM2.5）污染情况，该城市被选为典型的人口稠密、有住宅区和工业区的城市。 2012年12月至2013年11月，分四个季节在5个地点采集PM2.5样品。PM2.5年平均质量浓度为53.2+/-30.4μg/m(3)，冬季浓度最高，夏季浓度最低。在5个站点中，由于城市化和人为影响，PM2.5浓度在城市住宅站点最高，在郊区站点最低。 PM2.5的化学成分呈现明显的季节变化。此外，宁波市二次转化率较高，郊区二次成分比例最高，工业场地次生成分比例最低。宁波受来自中国内陆、渤海、东南近海、黄海和韩国东海岸的五个主要气团控制。这些气团的相对贡献因季节而异，冬春季节以渤海气团为主，夏季以东南沿海气团为主，秋季以黄海气团和朝鲜沿海气团为主。大陆气团与高 PM2.5 浓度相关，表明它主要输送初级排放。相比之下，海洋气团中二次形成污染物的浓度比较高，这表明海风控制了沿海城市空气污染的时空变化。 (C) 2017 年由 Elsevier B.V. 出版
Rapid economic development and urbanization in China has been concentrated in coastal cities, resulting in haze and photochemical smog issues, especially in the densely-populated Yangtze River Delta. In this study, we explore particulate matter (specifically PM2.5) pollution in a city in Zhejiang Province (Ningbo), chosen to represent a typical, densely-populated urban city with residential and industrial sections. PM2.5 samples were collected at five sites in four seasons from Dec. 2012 to Nov. 2013. The annual average PM2.5 mass concentration was 53.2 +/- 30.4 mu g/m(3), with the highest concentration in winter and lowest in summer. Among the five sites, PM2.5 concentration was highest in an urban residential site and lowest in a suburban site, due to effects of urbanization and the anthropogenic influences. The chemical components of PM2.5 show significant seasonal variation. In addition, secondary transformation was high in Ningbo, with the highest proportion of secondary components found at a suburban site and the lowest at the industrial sites. Ningbo is controlled by five major air masses originating from inland China, from the Bohai Sea, offshore from the southeast, the Yellow Sea, and off the east coast of Korea. The relative contributions of these air masses differ, by season, with the Bohai Sea air mass dominating in winter and spring, the maritime southeast air mass in summer, and the YellowSea and coastal Korean air masses dominating in autumn. The continental air mass is associated with a high PM2.5 concentration, indicating that it is primarily transports primary emissions. In contrast, the concentration ratios among secondary formed pollutants were higher in the maritime air masses, which suggests that sea breezes control temporal and spatial variations of air pollution over coastal cities. (C) 2017 Published by Elsevier B.V.