Wu An-Nan, Huang Xiao-Juan, He Ren-Jiang, Li Jin-Jian, Ye Mo-Lin, Wu Tao, Xiao Zhi-Dan, Liu Zi-Rui, Wang Yue-Si, Zhang Xiao-Ling, Zhang Jun-Ke
Plateau Atmosphere and Environment Key Laboratory of Sichuan Province, School of Atmospheric Sciences, Chengdu University of Information Technology, Chengdu 610225, China.
College of Public Health, Southwest Medical University, Luzhou 646000, China.
Huan Jing Ke Xue. 2022 Mar 8;43(3):1170-1179. doi: 10.13227/j.hjkx.202106019.
To investigate the PM pollution in the southern Sichuan urban agglomeration after the implementation of China's Air Pollution Prevention and Control Action Plan (APPCAP), PM samples were simultaneously collected in four cities (Neijiang, Zigong, Yibin, and Luzhou) from November 7 to 19, 2018. The pollution characteristics of PM and main water-soluble ions were analyzed in combination with the synoptic situation, and the influence of regional transport on atmospheric pollution was also discussed in this study. The results showed that the mean (PM) in this region was (67.2±38.3) μg·m, being highest in Luzhou and lowest in Neijiang. The proportion of SNA (SO, NO, and NH) in PM was 33.3%, among which NO was dominant. From the intermediate stage (2015) to the end(2018) of the implementation of APPCAP, (PM) values were increased by 13.8%, 47.2%, and 69.1% in Neijiang, Yibin, and Luzhou, respectively, though unchanged in Zigong. Due to the significant reduction in (SO) but slight decrease or increase in (NO), as well as the lack of controlling NH emissions, from 2015 to 2018, (NO) had increased by 36.7%-116.0%, whereas (SO) decreased by 19.8%-40.2%, and (NH) changed slightly in four cities. On haze days, the nitrogen oxidation rate (NOR) increased by 60.0%-118.2%, whereas the sulfur oxidation rate (SOR) increased slightly or decreased, leading to a significant increase in (NO) (2.7-3.0 times that on clean days) and NO/SO mass ratios (1.7-1.9 on haze days). These values indicated that the secondary formation of nitrate was the dominant chemical mechanism in this haze process. On haze days, the PM pollution in this region was mainly affected by the regional transport within Sichuan Basin, particularly by the northeasterly air masses passing through Chongqing.
为研究中国《大气污染防治行动计划》实施后川南城市群的细颗粒物（PM）污染情况，于2018年11月7日至19日在四个城市（内江、自贡、宜宾和泸州）同步采集了PM样本。结合天气形势分析了PM及主要水溶性离子的污染特征，并探讨了区域传输对大气污染的影响。结果表明，该区域PM均值为（67.2±38.3）μg·m ，泸州最高，内江最低。PM中硫硝铵（SO 、NO 和NH ）占比为33.3%，其中以NO 为主。从《大气污染防治行动计划》实施中期（2015年）至末期（2018年），内江、宜宾和泸州的PM值分别上升了13.8%、47.2%和69.1%，而自贡未变。由于SO 大幅下降但NO 略有下降或上升，以及NH 排放缺乏管控，2015年至2018年，四个城市的NO 上升了36.7% - 116.0%，SO 下降了19.8% - 40.2%，NH 变化不大。在霾天，氮氧化率（NOR）上升了60.0% - 118.2%，而硫氧化率（SOR）略有上升或下降，导致NO 显著增加（为清洁天的2.7 - 3.0倍）以及NO /SO 质量比增大（霾天为1.7 - 1.9）。这些数值表明，硝酸盐的二次形成是该霾过程中的主要化学机制。在霾天，该区域的PM污染主要受四川盆地内区域传输影响，特别是受经过重庆的东北气流影响。
