摘要
基于《大气污染防治行动计划》实施前后,在污染严重的冬季(2013年和2018年12月同期),采集郑州市监测站的PM_(2.5)样品,分析PM_(2.5)化学组成,通过对比分析PM_(2.5)中的EC、OC、水溶性离子和金属元素的浓度变化来评估PM_(2.5)浓度及化学组成的变化,同时选取不同阶段重污染过程,探究PM_(2.5)浓度及组成的变化.结果表明:(1)郑州市冬季ρ(PM_(2.5))平均值由2013年的(215.38±107.28)μg·m^(-3)下降至2018年的(77.45±49.81)μg·m^(-3),下降率高达64%.(2)PM_(2.5)中EC、K^(+)、SO_(4)^(2-)和Cl^(-),分别下降了85%、80%、78%和72%;OC、NH_(4)^(+)和NO_(3)^(-)下降幅度较小,分别为50%、41%和32%.(3)与2013年冬季相比,2018年冬季OC/EC的值升高了2.6倍,二次有机碳在OC中占比升高至57%;同时,硫氧化率和氮氧化率的值分别升高了1.5倍和1.0倍,表明郑州市二次污染较为严重,二次转化程度升高.(4)NO_(3)^(-)/SO_(4)^(2-)(质量比)由2013年的0.8±0.2升高至2018年2.5±1.0,表明郑州市移动源贡献上升并且超过固定源成为冬季大气污染的主要来源.(5)不同阶段重污染过程对比结果显示,与2013年相比,2018年重污染过程中PM_(2.5)浓度下降显著,峰值浓度下降了61%,主要化学组成由OC、NO_(3)^(-)、SO_(4)^(2-)和NH_(4)^(+)变为OC、NO_(3)^(-)和NH_(4)^(+).研究结果表明郑州市一次排放源管控取得了显著的成效,但二次生成对PM_(2.5)贡献呈现升高趋势,因此未来需要关注二次生成的影响.
The Air Pollution Prevention and Control Action Plan(APPCAP)was promulgated in China in 2013.To explore the effectiveness of APPCAP on PM_(2.5) in winter in Zhengzhou,PM_(2.5) samples were collected in Zhengzhou Monitoring Center during December 2013 and December 2018.The chemical composition of PM_(2.5) was analyzed,including EC,OC,water soluble ions,and metal elements.Pollution episodes under different stages were selected to investigate the changes in PM_(2.5) concentration and composition.The results showed that:①The average concentration of PM_(2.5) in winter in Zhengzhou decreased from(215.38±107.28)μg·m^(−3) in 2013 to(77.45±49.81)μg·m^(−3) in 2018,with a decrease rate of 64%.②The concentrations of EC,K^(+),SO_(4)^(2-),and Cl−decreased by 85%,80%,78%,and 72%,respectively,and the decrease rate in OC,NH_(4)^(+),and NO_(3)^(-)was 50%,41%,and 32%,respectively.③Compared with those in winter of 2013,the ratios of OC/EC in winter of 2018 increased by 2.6 times,and the proportion of secondary organic carbon in OC increased to 57%;meanwhile,values of sulfur oxidation rate and nitrogen oxidation rate increased by 1.5 and 1.0 times,respectively,indicating heavy secondary pollution in Zhengzhou.④The mass ratios of NO_(3)^(-)/SO_(4)^(2-)increased from 0.8±0.2 in 2013 to 2.5±1.0 in 2018,indicating that the contribution of mobile sources increased and surpassed fixed sources as the main source in Zhengzhou.⑤The comparison results of different stages of the heavy pollution process showed thatρ(PM_(2.5))decreased significantly in 2018 compared with that in 2013,with the peak concentration decreasing by 61%.The main chemical composition changed from OC,NO_(3)^(-),SO_(4)^(2-),and NH_(4)^(+)to OC,NO_(3)^(-),and NH_(4)^(+).The results indicated that the primary emission source control in Zhengzhou had achieved remarkable effects,but the contribution of secondary generation to PM_(2.5) showed an elevated trend;thus,the influence of secondary generation requires further attention in the future.
作者
徐艺斐
袁明浩
王晶晶
陶杰
周伟峰
XU Yi-fei;YUAN Ming-hao;WANG Jing-jing;TAO Jie;ZHOU Wei-feng(Henan Zhengzhou Ecological Environment Monitoring Center,Zhengzhou 450001,China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2024年第7期3849-3857,共9页
Environmental Science
基金
郑州市PM_(2.5)与O_(3)协同控制监测项目(20220347A)
国家重点研发计划项目(2017YFC0212403)。
关键词
大气污染防治行动计划
PM_(2.5)
化学组成
二次生成
重污染过程
Air Pollution Prevention and Control Action Plan
PM_(2.5)
chemical composition
secondary generation
pollution episodes
