Direct emissions from the use of coal in North China are one of the important sources of winter mites
The cause of the formation of winter sorghum in North China has always been a hot issue for everyone to discuss. In recent years, the general research has paid more attention to the formation of these severe sputum (PM2.5 is more than 250μg m-3), and then neglected light and moderate sputum. We calculated the number of ash days in winter in nine major cities in the North China Plain during the winter of 2014-2015. It was found that the number of mild and moderate sputum days accounted for 22-63% of the total winter in different cities, while the severe sputum accounted for 4-32. %. Light and moderate sputum can maintain high frequency and maintain multiple days and other characteristics will have a greater impact on human health and climate. In addition, mild to moderate sputum is also an important early stage for the formation of severe sputum. Prof. Li Wei from the Environmental Research Institute of Shandong University used microscopic means such as transmission electron microscopy to directly observe the morphology and composition characteristics of single particles. They found that a large number of organic particles emitted at one time appeared in the sputum. This is due to the low humidity during the light and moderate enthalpy in winter, which is not prone to heterogeneous reactions and the weak photochemical ability of the whole atmosphere. At this time, the particulate matter discharged at one time in the atmosphere accounts for a large proportion. In this study, the source characteristics of primary organic particles were further tracked by comparison with organic particles directly combusted by coal-fired furnaces. It was found that about 70% of these organic particles were derived from direct emissions from domestic coal combustion. Although atmospheric heavy industry emissions in North China are one of the important causes of regional plutonium, the study shows that direct discharge of large quantities of particulate matter from loose coal combustion is also an important factor in the formation of light and moderate plutonium. This provides further strong evidence for further governance of winter fog.
Currently, the results are published in "Atmospheric Physical Chemistry." (Source: Science Network)
