2015—2020年我国PM_(2.5)改善与气态前体物减排响应分析  

Impact of gaseous pollutants reduction on PM_(2.5) in China from 2015 to 2020

作　　者：徐洋 汤克勤[1] 魏崇 李楠 XU Yang;TANG Keqin;WEI Chong;LI Nan(School of Environmental Science and Engineering,Nanjing University of Information Science&Technology,Nanjing 210044;Shanghai Advanced Research Institute,Chinese Academy of Sciences,Shanghai 200120)

机构地区：[1]南京信息工程大学环境科学与工程学院,南京210044 [2]中国科学院上海高等研究院,上海200120

出　　处：《环境科学学报》2024年第6期217-225,共9页Acta Scientiae Circumstantiae

基　　金：国家重点研发计划(No.2022YFC3701005)。

摘　　要：自2013年以来,随着大气污染防治行动计划的持续推行,我国大部分城市PM_(2.5)污染已得到显著改善,但不同区域PM_(2.5)改善与气态前体物减排的响应特征及年际变化研究尚不完善.本研究采用多渠道大气污染物观测数据(地基PM_(2.5)、NO_(2)和SO_(2),以及韦晶PM_(2.5)、葵花PM_(2.5)和IASI-NH_(3)数据集),综合分析2015—2020年我国PM_(2.5)改善与气态前体物减排的响应关系和影响因素.结果表明,随着大气污染物排放的显著降低(-2.64%~-11.02%a-1),我国PM_(2.5)(-6.64%a-1)和气态前体物NO_(2)(-3.47%a-1)、SO_(2)(-11.87%a-1)污染得到了有效控制,其中,SO_(2)的改善最为显著,而NH_(3)(-0.61%a-1)浓度下降较慢.我国整体PM_(2.5)与NO_(2)和SO_(2)浓度呈显著正相关关系,随着气态前体物的持续减排,该相关特征也呈逐年下降的趋势,但截止到2020年,PM_(2.5)与NO_(2)和SO_(2)的相关系数仍分别可达0.64和0.39.该结果表明气态前体物,尤其是NO_(2),仍是影响我国PM_(2.5)污染的主要因素.PM_(2.5)与NH_(3)的相关性整体较弱,主要原因为SO_(2)和NO_(2)浓度的快速下降导致其与NH_(3)中和反应的减少,进而导致NH_(3)浓度变化较小.进一步通过PM_(2.5)、NO_(2)和SO_(2)的逐年变化(dPM_(2.5)、dNO_(2)和dSO_(2))分析指出,我国大部分地区PM_(2.5)改善受NO_(2)的减排贡献更大,尤其在浙江、安徽、河南、陕西和重庆等地区,dPM_(2.5)与dNO_(2)的相关系数是dPM_(2.5)与dSO_(2)相关系数的3倍,且该特征呈逐年增强趋势(dPM_(2.5)与dNO_(2)相关系数的增幅为5.77%a-1);但少数地区(如山西、甘肃等)PM_(2.5)改善则更多受SO_(2)减排影响.综上结果表明,近年来我国PM_(2.5)的改善与NO_(2)和SO_(2)浓度的下降密切相关,且NO_(2)管控对PM_(2.5)改善的贡献较SO_(2)更加显著,NO_(2)的持续减排是现阶段和未来PM_(2.5)进一步深度改善的关键.Since 2013,the PM_(2.5) pollution has significantly reduced in most cities of China through the continual implementation of air pollution control plans.However,a comprehensive examination of the interannual variations in PM_(2.5) improvement and the impacts of gas precursors in different regions remains incomplete.In this study,an exhaustive analysis of multiple data sources related to atmospheric pollutants,including surface PM_(2.5),NO_(2),and SO_(2),as well as datasets from Weijing PM_(2.5),Himawari PM_(2.5),and IASI NH_(3),was conducted to explore the relationship between PM_(2.5) improvement and the reduction of gaseous precursors in China from 2015 to 2020.The results indicate that,concomitant with a significant reduction in atmospheric pollutant emissions(-2.64%to-11.02%a-1),the concentrations of PM_(2.5)(-6.64%a-1)and gaseous pollutants(NO_(2),-3.47%a-1 and SO_(2)-11.87%a-1)have effectively been controlled.A significant positive correlation between PM_(2.5) concentrations and the concentrations of both NO_(2) and SO_(2) in China is evident.Over the years,as gaseous precursor emissions continued to decline,this correlation exhibited a declining trend,yet by the close of 2020,remained substantial at 0.64 and 0.39,respectively.These results underscore that gaseous precursors,particularly NO_(2),persist as the primary factors influencing PM_(2.5) pollution in China.The correlation between PM_(2.5) and NH_(3) is generally weaker.This is mainly due to the rapid decline in SO_(2) and NO_(2) concentrations,which leads to a decrease in their neutralization reactions with NH_(3) and,consequently,smaller variations in NH_(3) concentrations.Further analysis of the changes in PM_(2.5),NO_(2),and SO_(2)(dPM_(2.5),dNO_(2),and dSO_(2))indicates that,in most regions of China,the improvement in PM_(2.5) is more strongly influenced by the reduction of NO_(2).Especially in regions such as Zhejiang,Anhui,Henan,Shaanxi,and Chongqing,the correlation between dPM_(2.5) and dNO_(2) is three times stronger than that with dSO_(2),an

关 键 词：PM_(2.5) NO_(2) SO_(2.) NH_(3) 减排响应 

分 类 号：X51[环境科学与工程—环境工程]