新冠疫情管控措施对郑州市PM2.5浓度、粒径分布、组分和来源的影响 |
摘要点击 3894 全文点击 1104 投稿时间:2021-09-09 修订日期:2021-11-05 |
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中文关键词 郑州市 疫情 颗粒物 粒径分布 化学组分 正定矩阵因子分解(PMF) |
英文关键词 Zhengzhou COVID-19 epidemic particulate matter size distribution chemical composition positive matrix factorization (PMF) |
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中文摘要 |
新冠肺炎疫情(COVID-19)管控期间是一次典型的极限减排情景,是研究管控措施对大气颗粒物影响的重要机会.本研究于2020年1月16~31日利用在线观测仪器对郑州市PM2.5进行观测,分别探究管控前(2020年1月16~23日)与管控期间(2020年1月24~31日) PM2.5浓度、粒径分布、化学组分、来源解析和传输影响的变化特征.结果表明,相较于管控前,管控期间郑州市大气PM2.5浓度下降4.8%.粒径分布特征表明,管控期间0.06~1.6 μm的颗粒物质量浓度和数浓度下降显著.PM2.5组分特征表明,SO42-、NO3-和NH4+等二次无机离子是PM2.5中占比最大的组分,管控期间NO3-浓度的下降对PM2.5的下降有显著贡献.采用正定矩阵因子分解模型(PMF)解析PM2.5来源,结果表明郑州市PM2.5主要来源为二次源、燃烧源、机动车源、工业源和扬尘源,管控期间机动车源、工业源和扬尘源等源排放下降.利用后向轨迹法和潜在源贡献因子法评估传输的影响,结果表明管控期间周边地区的传输对郑州市PM2.5浓度的影响下降.综上,未来郑州市应持续管控机动车源和工业源,并加强区域联防联控. |
英文摘要 |
The COVID-19 lockdown was a typical occurrence of extreme emission reduction, which presented an opportunity to study the influence of control measures on particulate matter. Observations were conducted from January 16 to 31, 2020 using online observation instruments to investigate the characteristics of PM2.5 concentration, particle size distribution, chemical composition, source, and transport before (January 16-23, 2020) and during (January 24-31, 2020) the COVID-19 lockdown in Zhengzhou. The results showed that the atmospheric PM2.5 concentration decreased by 4.8% during the control period compared with that before the control in Zhengzhou. The particle size distribution characteristics indicated that there was a significant decrease in the mass concentration and number concentration of particles in the size range of 0.06 to 1.6 μm during the control period. The chemical composition characteristics of PM2.5 showed that secondary inorganic ions (sulfate, nitrate, and ammonium) were the dominant component of PM2.5, and the significant increase in PM2.5 was mainly owing to the decrease in NO3- concentration during the control period. The main sources of PM2.5 identified by the positive matrix factorization (PMF) model were secondary sources, combustion sources, vehicle sources, industrial sources, and dust sources. The emissions from vehicle sources, industrial sources, and dust sources decreased significantly during the control period. The results of analyses using the backward trajectory method and potential source contribution factor method indicated that the effects of transport from surrounding areas on PM2.5 concentration decreased during the control period. In summary, vehicle and industrial sources should be continuously controlled, and regional combined prevention and control should be strengthened in the future in Zhengzhou. |
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