湖北咸宁细颗粒物PM2.5来源

为了解咸宁细颗粒物（PM_2.5）来源,对2019年在湖北咸宁两个环境受体点位采集的不同季节大气中PM_2.5样品中的主要成分和化学元素进行统计研究；通过颗粒物排放源采样建立本地特征源谱,用化学质量平衡（CMB）受体模型解析其来源；通过VOCs离线监测数据分析其中二次气溶胶（SOA）生成关键组分,并对关键组分进行来源解析.结果表明,咸宁市PM_2.5超标情况主要出现在冬季,PM_2.5中主要化学成分以水溶性无机盐和含碳组分为主；一次解析揭示硝酸盐、硫酸盐和铵盐等的二次转化对PM_2.5浓度的贡献最大,总贡献率在45%以上；二次解析揭示工业源、机动车源及电厂对PM_2.5浓度的贡献最大；VOCs对二次有机气溶胶贡献最高的组分为芳香烃,关键组分为苯、甲苯、间/对-二甲苯和乙基苯,对关键组分来源分析发现主要来源为溶剂使用.控制工业排放、机动车排放及调整能源结构是目前控制咸宁PM_2.5的主要途径,同时也要考虑控制溶剂排放的芳香烃.

Source Apportionment of Fine Particles in Xianning, Hubei

To understand the sources of fine particulate matter PM_2.5 in Xianning, a statistical study was conducted on the major components and chemical elements in atmospheric PM_2.5 samples collected at two environmental receptor sites in Xianning, Hubei in 2019 in different seasons. Local characteristic source spectra were established through particulate matter emission source sampling, and their sources were resolved using a chemical mass balance （CMB） receptor model. Additionally, the key components of secondary aerosol （SOA） generation were analyzed using offline monitoring of VOCs, and the key components were analyzed using source analysis. The results showed that PM_2.5 exceedances in Xianning mainly occurred in winter, and the main chemical components in PM_2.5 were mainly water-soluble inorganic salts and carbon-containing components. Primary analysis revealed that secondary transformations of nitrate, sulphate, and ammonium salts made the largest contribution to PM_2.5 concentrations, with a total contribution of over 45%； secondary analysis revealed that industrial sources, motor vehicle sources, and power plants made the largest contribution to PM_2.5 concentrations. The components of VOCs that made the highest contribution to secondary organic aerosols were aromatic hydrocarbons, with the key components being benzene, toluene, m-xylene, paraxylene, and ethylbenzene. Analysis of the sources of the key components revealed that the main source was solvent use. Controlling industrial emissions and motor vehicle emissions and adjusting the energy structure are currently the primary ways to control PM_2.5 in Xianning, although controlling aromatic hydrocarbons from solvent emissions should also be considered.