高时间分辨率大气细颗粒物动态来源解析与综合校验方法体系的研究

Recently, regional air pollution complex has occurred in many regions of China, among which, the fine particulate matter (PM2.5) concentrations in North China exhibit explosive increase phenomena characterized with large amplitude and fast variation. Rapid and accurate source apportionment is the foundation of effective air quality management. However, primarily due to low time resolution, the traditional offline source apportionment method cannot catch rapid variations of PM2.5 compositions and sources. There is an urgent need to develop and improve the high time-resolved online monitoring and online source apportionment techniques, to help to understand the causes of heavy pollutions and air pollution control researches. Several online source apportionment methods appear in recent years, but still have their challenges such as the need for data quality evaluation, and lack of verifications of source apportionment results. This research will combine online data from multiple instruments, receptor model and air quality model to develop (1) methods for 1 h time-resolved online PM2.5 source apportionment, (2) ensemble PM2.5 source apportionment results based on several receptor models and air quality model, and (3) a validation system for online source apportionment results. This study aims to realize high time-resolved PM2.5 online source apportionment, and constrain and improve the accuracy of source apportionment results from multiple angles.

我国近年区域大气复合污染形势严峻，其中，华北地区秋冬季PM2.5的“爆发性”增长问题突出：浓度变幅大、变速快。快速、准确地获取PM2.5的来源贡献是制定有效防治措施的重要基础。然而，传统离线源解析方法的时间分辨率较低，难以捕捉重污染过程中PM2.5组成和来源的快速变化，亟需发展和完善高时间分辨率的在线监测与源解析技术，支撑重污染事件的追因与控制。近期出现的几种在线源解析技术尚存在监测数据与源解析结果不够全面或准确性待检验等瓶颈。本研究拟在获取高时间分辨率PM2.5有机和无机组分的在线监测数据基础上，结合本地化源谱测试和更丰富的源示踪物种，同步开展受体及空气质量模型源解析，建立：①1小时分辨率的PM2.5在线源解析方法；②多种受体模型和空气质量模型的源解析结果集合；③源解析结果准确性的综合验证体系。本研究旨在实现高时间分辨率PM2.5在线源解析方法，并从多个角度约束和提升源解析结果的准确性。

华北地区秋冬季PM2.5的“爆发性”增长问题，需要快速、准确获取PM2.5的来源贡献，从而制定有效防治措施。本项目：1）建立了华北地区典型排放源的精细化成分谱（颗粒相和气相组分），为源解析提供基础数据。在我国10个省市166户农家实测并获得本地化民用固体燃料燃烧的成分谱；实测不同排放标准、道路等级和行驶速度下道路源和不同运行工况下非道路源、船舶尾气的排放特征以及各种工业锅炉和工业过程源的排放特征；2）建立高时间分辨率细颗粒物的来源解析方法，为量化华北地区霾污染的来源识别提供技术支持。基于大气细颗粒物全组分的自动在线检测，结合多种受体模型、单颗粒质谱、耦合在线源解析模块的空气质量模型、多元稳定同位素等手段，开展高时间分辨率的细颗粒来源解析，优化了PM2.5源解析方法体系；3）建立细颗粒物源解析结果的综合诊断与校验体系，为评判细颗粒物源解析的准确性提供依据。以华北地区秋冬季重污染过程为例，采用多模型的综合交叉验证，并用14C结果评判源解析结果的准确性。项目研究成果可为我国PM2.5的快速、在线源解析研究以及源解析结果准确性的综合诊断与校验提供重要参考。