Zhang Jian, Liu Lei, Wang Yuanyuan, Ren Yong, Wang Xin, Shi Zongbo, Zhang Daizhou, Che Huizheng, Zhao Hujia, Liu Yanfei, Niu Hongya, Chen Jianmin, Zhang Xiaoye, Lingaswamy A P, Wang Zifa, Li Weijun
Environment Research Institute, Shandong University, Jinan, Shandong 250100, China; Department of Atmospheric Sciences, School of Earth Sciences, Zhejiang University, Hangzhou 320007, China.
Environment Research Institute, Shandong University, Jinan, Shandong 250100, China.
Environ Pollut. 2017 Dec;231(Pt 1):357-366. doi: 10.1016/j.envpol.2017.07.102. Epub 2017 Sep 25.
The characteristics of aerosol particles have been poorly evaluated even though haze episodes frequently occur in winter in Northeast China. OC/EC analysis, ion chromatography, and transmission electron microscopy (TEM) were used to investigate the organic carbon (OC) and elemental carbon (EC), and soluble ions in PM and the mixing state of individual particles during a severe wintertime haze episode in Northeast China. The organic matter (OM), NH, SO, and NO concentrations in PM were 89.5 μg/m, 24.2 μg/m, 28.1 μg/m, and 32.8 μg/m on the haze days, respectively. TEM observations further showed that over 80% of the haze particles contained primary organic aerosols (POAs). Based on a comparison of the data obtained during the haze formation, we generate the following synthetic model of the process: (1) Stable synoptic meteorological conditions drove the haze formation. (2) The early stage of haze formation (light or moderate haze) was mainly caused by the enrichment of POAs from coal burning for household heating and cooking. (3) High levels of secondary organic aerosols (SOAs), sulfates, and nitrates formation via heterogeneous reactions together with POAs accumulation promoted to the evolution from light or moderate to severe haze. Compared to the severe haze episodes over the North China Plain, the PM in Northeast China analyzed in the present study contained similar sulfate, higher SOA, and lower nitrate contents. Our results suggest that most of the POAs and secondary particles were likely related to emissions from coal-burning residential stoves in rural outskirts and small boilers in urban areas. The inefficient burning of coal for household heating and cooking should be monitored during wintertime in Northeast China.
尽管中国东北地区冬季经常出现雾霾天气，但气溶胶颗粒的特征尚未得到充分评估。利用有机碳/元素碳分析、离子色谱法和透射电子显微镜（TEM），对中国东北地区一次严重冬季雾霾事件期间细颗粒物中的有机碳（OC）、元素碳（EC）、可溶性离子以及单个颗粒的混合状态进行了研究。雾霾天细颗粒物中的有机物（OM）、NH₄⁺、SO₄²⁻和NO₃⁻浓度分别为89.5 μg/m³、24.2 μg/m³、28.1 μg/m³和32.8 μg/m³。TEM观测进一步表明，超过80%的雾霾颗粒含有一次有机气溶胶（POA）。基于对雾霾形成过程中获得的数据进行比较，我们得出了以下合成模型：（1）稳定的天气形势驱动了雾霾的形成。（2）雾霾形成的早期阶段（轻度或中度雾霾）主要是由家庭取暖和烹饪燃煤产生的POA富集造成的。（3）通过非均相反应形成的高浓度二次有机气溶胶（SOA）、硫酸盐和硝酸盐，以及POA的积累，促使雾霾从轻度或中度向重度演变。与华北平原的严重雾霾事件相比，本研究分析的中国东北地区细颗粒物中的硫酸盐含量相似，SOA含量较高，硝酸盐含量较低。我们的结果表明，大多数POA和二次颗粒物可能与农村郊区的燃煤民用炉灶和城市地区的小型锅炉排放有关。中国东北地区冬季应监测家庭取暖和烹饪燃煤的低效燃烧情况。
