COVID-19管控前后不同污染阶段PM_(2.5)中二次无机离子变化特征  

Changes in Secondary Inorganic Ions in PM_(2.5)at Different Pollution Stages Before and After COVID-19 Control

作　　者：姜楠[1,2] 郝雪新 郝祺 魏云飞 张瑜[1,2] 吕政卿 张瑞芹[1,2] JIANG Nan;HAO Xue-xin;HAO Qi;WEI Yun-fei;ZHANG Yu;LüZheng-qing;ZHANG Rui-qin(College of Ecology and Environment,Zhengzhou University,Zhengzhou 450001,China;Institute of Environmental Science,Zhengzhou University,Zhengzhou 450001,China;Xiaogan Ecological Environment Bureau of Hubei Province,Xiaogan 432000,China)

机构地区：[1]郑州大学生态与环境学院,郑州450001 [2]郑州大学环境科学研究院,郑州450001 [3]湖北省孝感市生态环境局,孝感432000

出　　处：《环境科学》2023年第5期2430-2440,共11页Environmental Science

基　　金：国家自然科学基金项目(52170117);河南省重点研发与推广专项(212102310065)。

摘　　要：为探讨新冠肺炎疫情(COVID-19)管控前后不同污染阶段PM_(2.5)中二次无机离子变化特征,使用高分辨率(1 h)在线仪器对2019年12月15日至2020年2月15日郑州冬季气象、污染气体浓度和PM_(2.5)中水溶性离子水平进行在线监测,分析此次COVID-19管控前后霾过程的成因、大气污染物的日变化特征和在霾不同阶段下大气污染物的分布特征.结果表明,郑州主要受到高压脊控制,天气形势稳定,有利于大气污染物累积,二次无机气溶胶(SNA,包括SO_(2-)^(4)、NO_(3)^(-)和NH^(4+))是水溶性离子的主要组分,占比高达90%以上,COVID-19期间居家隔离措施对霾不同阶段下大气污染物的分布特征产生不同的影响,COVID-19期间PM_(2.5)在干净、发生和消散阶段的浓度比COVID-19前有所提高,但是发展阶段明显降低,居家隔离明显使PM_(2.5)高值降低了;NO_(2)、SO_(2)、NH_(3)和CO的浓度在霾发展阶段最高,呈现先增加后降低的趋势;COVID-19前O3在发展阶段浓度最低,但是COVID-19期间发展阶段浓度最高.COVID-19前期间不同时段[NH^(4+)]/[SO_(2-)^(4)]与[NO_(3)^(-)]/[SO_(2-)^(4)]的线性相关相关性均较强,说明居家隔离没改变NO_(3)^(-)的生成方式,均相反应始终是NO_(3)^(-)的主要生成方式之一,COVID-19前不同时段[excess-NH^(4+)]与[NO_(3)^(-)]的相关性均较高,郑州大气PM_(2.5)污染过程中NO_(3)^(-)生成与NH_(3)或NH^(4+)的增加有关.To investigate the change characteristics of secondary inorganic ions in PM_(2.5)at different pollution stages before and after COVID-19,the online monitoring of winter meteorological and atmospheric pollutant concentrations in Zhengzhou from December 15,2019 to February 15,2020 was conducted using a high-resolution(1 h)online instrument.This study analyzed the causes of the haze process of COVID-19,the diurnal variation characteristics of air pollutants,and the distribution characteristics of air pollutants at different stages of haze.The results showed that Zhengzhou was mainly controlled by the high-pressure ridge during the haze process,and the weather situation was stable,which was conducive to the accumulation of air pollutants.SNA was the main component of water-soluble ions,accounting for more than 90%.Home isolation measures during COVID-19 had different impacts on the distribution characteristics of air pollutants in different haze stages.After COVID-19,the concentration of PM_(2.5)in the clean,occurrence,and dissipation stages increased compared with that before COVID-19 but significantly decreased in the development stage.The home isolation policy significantly reduced the high value of PM_(2.5).The concentrations of NO_(2),SO_(2),NH_(3),and CO were the highest in the haze development stage,showing a trend of first increasing and then decreasing.The concentration of O3 was lowest in the pre-COVID-19 development stage but highest in the post-COVID-19 development stage.The linear correlation between[NH^(4+)]/[SO_(2-)^(4)]and[NO_(3)^(-)]/[SO_(2-)^(4)]at different time periods before and after COVID-19 was strong,indicating that the home isolation policy of COVID-19 did not change the generation mode of NO_(3)^(-),and the corresponding reaction was always the main generation mode of NO_(3)^(-).The correlation between[excess-NH^(4+)]and[NO_(3)^(-)]was high in different periods before COVID-19,and NO_(3)^(-)generation was related to the increase in NH_(3)or NH^(4+)in the process of PM_(2.5)pollution in Zhen

关 键 词：新冠肺炎疫情 PM_(2.5) 霾不同阶段 典型水溶性离子 污染气体 

分 类 号：X513[环境科学与工程—环境工程]