“大气十条”实施结束川南城市群秋季霾污染过程中水溶性离子特征  

Characteristics of Water-soluble Ions in an Autumn Haze Process in the Southern Sichuan Urban Agglomeration After the Implementation of China’s Air Pollution Prevention and Control Action Plan

作　　者：吴安南 黄小娟 何仁江 李金建 叶秣麟 吴涛 肖智丹 刘子锐[5] 王跃思[5] 张小玲 张军科 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;Neijiang Meteorological Office,Neijiang 641000,China;Yibin Meteorological Office,Yibin 644000,China;State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry,Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029,China;Faculty of Geosciences and Environmental Engineering,Southwest Jiaotong University,Chengdu 611756,China)

机构地区：[1]成都信息工程大学大气科学学院高原大气与环境四川省重点实验室,成都610225 [2]西南医科大学公共卫生学院,泸州646000 [3]内江市气象局,内江641000 [4]宜宾市气象局,宜宾644000 [5]中国科学院大气物理研究所大气边界层物理与大气化学国家重点实验室,北京100029 [6]西南交通大学地球科学与环境工程学院,成都611756

出　　处：《环境科学》2022年第3期1170-1179,共10页Environmental Science

基　　金：国家重点研发计划项目(2017YFC0210000);四川省重大科技专项(2018SZDZX0023);国家自然科学基金项目(41805095);四川省科技计划项目(2019YFS0476,2018SZ0288);成都信息工程大学科研基金项目(KYTZ201722)。

摘　　要：为了解《大气污染防治行动计划》(“大气十条”)实施结束后川南城市群大气PM_(2.5)的污染状况,于2018年11月7~19日在内江、自贡、宜宾和泸州这4个城市同步采集PM_(2.5)样品,结合天气形势分析了秋季PM_(2.5)及主要水溶性离子的污染特征,并利用后向轨迹聚类分析探讨了区域输送对该地区大气污染的影响.结果表明,川南城市群秋季大气平均ρ(PM_(2.5))为(67.2±38.3)μg·m^(-3),泸州最高而内江最低;SNA(SO_(4)^(2-)、NO_(3)^(-)和NH_(4)^(+))在PM_(2.5)中占比为33.3%,其中NO_(3)^(-)为首要离子组分;由“大气十条”实施中期(2015年)至实施结束(2018年),内江、宜宾和泸州秋季ρ(PM_(2.5))分别增加了13.8%、47.2%和69.1%,自贡持平;由于大气中ρ(SO_(2))大幅减少而ρ(NO_(2))减幅较小甚至增加,且缺乏对NH3排放的控制,从2015~2018年各城市秋季ρ(NO_(3)^(-))增加了36.7%~116.0%,ρ(SO_(2)-4)降低了19.8%~40.2%,ρ(NH_(4)^(+))则变化较小;霾天,表观氮氧化率NOR增加了60.0%~118.2%,而表观硫氧化率SOR增幅较小甚至下降,ρ(NO_(3)^(-))增加显著,是清洁天2.7~3.0倍,NO_(3)^(-)/SO_(2)-4比值也上升至1.7~1.9,说明硝酸盐的二次生成是此次霾污染过程形成的主要化学机制;霾天川南城市群主要受四川盆地内区域输送(尤其是经过重庆的东北气流)的影响.To investigate the PM_(2.5)pollution in the southern Sichuan urban agglomeration after the implementation of China’s Air Pollution Prevention and Control Action Plan(APPCAP),PM_(2.5)samples were simultaneously collected in four cities(Neijiang,Zigong,Yibin,and Luzhou)from November 7 to 19,2018.The pollution characteristics of PM_(2.5)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 meanρ(PM_(2.5))in this region was(67.2±38.3)μg·m^(-3),being highest in Luzhou and lowest in Neijiang.The proportion of SNA(SO_(4)^(2-),NO_(3)-,and NH_(4)^(+))in PM_(2.5)was 33.3%,among which NO_(3)^(-)was dominant.From the intermediate stage(2015)to the end(2018)of the implementation of APPCAP,ρ(PM_(2.5))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 inρ(SO_(2))but slight decrease or increase inρ(NO_(2)),as well as the lack of controlling NH3emissions,from 2015 to 2018,ρ(NO_(3)-)had increased by 36.7%-116.0%,whereasρ(SO_(4)^(2-))decreased by 19.8%-40.2%,andρ(NH_(4)^(+))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 inρ(NO_(3)-)(2.7-3.0 times that on clean days)and NO_(3)-/SO_(4)^(2-)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_(2.5)pollution in this region was mainly affected by the regional transport within Sichuan Basin,particularly by the northeasterly air masses passing through Chongqing.

关 键 词：PM_(2.5) 水溶性离子 川南城市群 霾 后向轨迹 

分 类 号：X513[环境科学与工程—环境工程]