浙江省细颗粒物碳质气溶胶组分表征方法及污染特征研究

Characterization methods and pollution characteristics of fine particulate matter carbon aerosol in Zhejiang Province

为深入探究大气细颗粒物(PM_(2.5))碳质气溶胶组分(碳组分)表征方法,于2021年1-12月,在浙江省11个地市同期开展环境空气PM_(2.5)样品采集和分析工作,比较美国国家职业安全卫生研究所(NIOSH)协议和保护能见度多部门监测计划(IMPROVE)的代替协议(IMPROVE-A协议)测定样品的结果差异。结果表明:无氧阶段最高温度设置为870℃的NIOSH(NIOSH870)协议由于在氦气气氛下的解析温度高,测得PM_(2.5)样品中有机碳(OC)组分占比较IMPROVE-A协议大;对于IMPROVE-A协议而言,热光反射法校正的元素碳(EC)比热光透射法校正的结果大,在污染越严重、负载量越大的滤膜上,光学校正带来的差异越明显。通过开展浙江省部分地区的PM_(2.5)碳组分污染特征研究,发现PM_(2.5)中碳组分主要来自生物质燃烧、燃煤和机动车尾气排放。

In order to conduct a thorough investigation into the characterization of carbonaceous aerosol components in atmospheric fine particulate matter(PM_(2.5)),PM_(2.5) samples were collected and analyzed in 11 cities in Zhejiang Province from January to December 2021.The collected samples were used to compared the difference of National Institute for Occupational Safety and Health(NIOSH) protocols and the Multi-Sectoral Monitoring Program for Protecting Visibility(IMPROVE) substitution protocol(IMPROVE-A) for determination of carbon components.The results showed that the NIOSH protocol with the maximum temperature setting of 870 ℃(NIOSH870) in the anoxic phase measured a larger proportion of organic carbon(OC) components in the PM_(2.5) samples than the IMPROVE-A protocol due to the high resolving temperature in the helium atmosphere,and that the elemental carbon(EC) corrected by the thermo-optical reflectance method was larger than that by the thermo-optical transmittance method for the IMPROVE-A protocol.The difference between the correction methods was more apparent in filter membranes with higher pollution levels and greater load capacities.Through the research conducted on the carbon component pollution characteristics of PM_(2.5 )in certain areas of Zhejiang Province,it was discovered that the main sources of carbon in PM_(2.5) were biomass combustion,coal burning,and motor vehicle exhaust emissions.