Yang Yang, Li Xing-Ru, Chen Xi, Liu Shui-Qiao, Liu Yu-Si, Xu Jing, Wang Li-Li, Tao Ming-Hui, Wang Ge-Hui
Analysis and Testing Center, Department of Chemistry, Capital Normal University, Beijing 100048, China.
Key Laboratory of Geographic Information Science, Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai 200241, China.
Huan Jing Ke Xue. 2018 Dec 8;39(12):5315-5322. doi: 10.13227/j.hjkx.201804237.
To understand the evolution of the physical and chemical properties of dust aerosols in the atmosphere, the concentrations and chemical compositions of differently sized particles were continuously observed and analyzed using an ion chromatograph and carbonaceous analyzer during the outbreak of dust in May 2017 in Beijing. The concentrations of total suspended particulate (TSP), water-soluble organic carbon (WSOC), elemental carbon (EC), OC, and water-soluble inorganic ions were (2237.59±681.49), (29.90±18.05), (1.46±3.05), (67.35±29.07), and (136.75±46.38) μg·m during the dust period, respectively, and significantly exceeded that of the non-dust period, except for EC. The Na, NH, K, Mg, Ca, Cl, NO, SO, and WSOC concentrations during the dust storm period were 11.55, 3.00, 14.88, 14.89, 9.40, 4.60, 2.40, 3.91, and 1.83 times higher than that during the non-dust period. The growth of crustal ions, such as Ca and K, was notably the largest and NH and NO were minimal. The size distribution indicates that crustal ions primarily occur in the coarse mode during the whole sampling campaign. The SO and NO ions are slightly bimodal during the dust storm, with a dominant peak in the coarse mode at 4.7-5.8 μm and a very minor peak in the fine mode with a size range of 0.43-0.65 μm. During the non-dust period, SO is the dominant mode in the fine mode, while NO changes little compared with that during the dust period, which indicates that heterogeneous reaction with crustal ions is the main formation mechanism of NO in the coarse mode. A significant positive correlation was observed between SO and the sum of crustal ions during the dust period, indicating that the source of SO during the dust period is remote transmission of the dust storm. During the non-dust period, the positive correlation of SO with NH indicates that secondary formation is the main source of SO. Based on correlation analysis of NO with crustal ions and NH, both remote transmission and secondary formation are the sources of NO during the dust storm and heterogeneous reactions are predominant during the non-dust period.
为了解大气中沙尘气溶胶物理和化学性质的演变，于2017年5月北京沙尘暴发期间，使用离子色谱仪和碳质分析仪对不同粒径颗粒物的浓度和化学成分进行了连续观测与分析。沙尘期总悬浮颗粒物（TSP）、水溶性有机碳（WSOC）、元素碳（EC）、有机碳（OC）和水溶性无机离子的浓度分别为（2237.59±681.49）、（29.90±18.05）、（1.46±3.05）、（67.35±29.07）和（136.75±46.38）μg·m ，除EC外，均显著超过非沙尘期。沙尘暴期间Na、NH、K、Mg、Ca、Cl、NO、SO和WSOC的浓度分别比非沙尘期高11.55、3.00、14.88、14.89、9.40、4.60、2.40、3.91和1.83倍。Ca和K等地壳离子的增长最为显著，NH和NO的增长最小。粒径分布表明，在整个采样过程中，地壳离子主要出现在粗模态中。沙尘暴期间，SO和NO离子呈轻微双峰分布，粗模态中的主峰出现在4.7 - 5.8μm，细模态中的次峰出现在0.43 - 0.65μm范围内。在非沙尘期，SO在细模态中占主导地位，而NO与沙尘期相比变化不大，这表明与地壳离子的非均相反应是粗模态中NO的主要形成机制。沙尘期SO与地壳离子总和之间存在显著正相关，表明沙尘期SO的来源是沙尘暴的远距离传输。在非沙尘期，SO与NH的正相关表明二次形成是SO的主要来源。基于NO与地壳离子和NH的相关性分析，远距离传输和二次形成都是沙尘暴期间NO的来源，非沙尘期非均相反应占主导。
