基于示踪物在线测量并耦合受体和源模型的细颗粒物实时溯源方法及在长三角地区的应用研究

Identification of various sources and quantification of their contributions are important scientific basis for developing detailed PM2.5 pollution control strategies. The current researches related to PM2.5 source apportionment generally use filter analysis and receptor models, emissions inventory and chemical models, these methods generally meet three scientific bottlenecks: (1) low-temporal resolution, and it is hard to grasp the changes of the pollution episodes; (2) online measurement of organic molecular markers are almost blank, thus it is difficult to quickly get changes of the sources; (3) receptor models and chemical models are dependent with each other, both with merits and limits, there is no coupled methodology to quantify PM2.5 sources especially secondary aerosol. In this project, we will develop a new methodology coupled with both receptor models and chemical models based on online tracer measurement to quantify PM2.5 sources with high time resolution and source sectors. We plan to develop robust online measurement capabilities for a range of organic molecular makers, elemental tracers, ions, elemental and organic carbon. Based on the online measurement of the PM2.5 species, different receptor models will be applied and verified to identify the most suitable method to do online source apportionment. Through cross verification of the source apportionment results based on “tracer observation – receptor models” and “emissions – chemical transport models”, we plan to develop a “ROM-SOM” hybrid algorithm for online source apportionment. Through the application of the above-mentioned techniques to the Yangtze River Delta, more insights will be gained on the sources of PM2.5 in this region.

快速定量识别污染源贡献是PM2.5精细化管理的重要科学前提。已有PM2.5溯源多采用滤膜分析结合受体模型、源清单结合数值模型开展研究，存在三个科技瓶颈：（1）时间分辨率低，难以快速捕捉污染过程变化；（2）有机分子示踪物在线测量尚属空白，难以快速获得示踪物信息；（3）受体和数值模型相对独立且各有优缺点，缺乏耦合方法量化PM2.5特别是二次气溶胶的源贡献。本项目拟基于有机分子和元素示踪物在线测量，研究耦合受体和数值模型的实时溯源新方法。本项目将攻关PM2.5中有机分子示踪物的在线测量方法，建立包括有机分子及元素示踪物、水溶性离子、元素碳、有机碳在内的在线测量系统；基于在线观测数据，开展受体模型实时溯源和比对验证，确定最优实时溯源受体模式方法；开展“示踪物观测-受体模型”和“源排放-数值模式”交叉验证，发展“ROM-SOM”耦合实时溯源方法，并通过在长三角示范应用，提升对PM2.5来源的认知。

本项目基于在线热脱附气溶胶气相色谱-质谱仪（TAG-GC/MS），建立了PM2.5中极性及非极性有机分子示踪物的定性定量和数据质控质保方法，可定量97种有机分子示踪物，填补了我国在实际连续观测条件下对痕量分子有机示踪物连续在线观测并获取准确可靠数据的空白；结合水溶性离子、元素碳/有机碳和金属元素在线分析仪，建立了大气PM2.5多化学组分在线测量系统，并先后在长三角典型城市（上海、常州）和华北平原典型工业城市（淄博）开展了秋冬季重污染过程外场观测，获得了丰富的PM2.5化学组分及有机和无机示踪物数据集；结合PM2.5多化学组分外场观测数据，建立了基于有机分子及元素示踪物实时观测数据的高时间分辨率受体模型MM-PMF源解析方法，可快速定量识别十余种污染源对PM2.5的浓度贡献；进一步提出了基于有机分子示踪物在线测量配合PM2.5化学组分观测，结合受体模型和三维化学传输模型，实现高分辨率PM2.5精细溯源的新思路，构建了耦合“示踪物在线观测-受体模式解析-高分辨率源清单-大气化学传输模型”的PM2.5精细化溯源新方法，实现了高时间分辨率、高源类分辨率、高区域贡献识别度的PM2.5精细化来源识别。在典型城市（上海、常州、淄博）开展了示范应用，为我国大气PM2.5污染防治提供了关键数据积累和技术支撑。.此外，本项目研究建立的有机分子示踪物技术在线测量及高时间分辨率快速耦合溯源新方法，也在进博会空气质量保障、冬奥会空气质量保障期间得到了应用，为PM2.5污染的快速精准溯源提供了关键技术支持。.本项目研究成果已发表标注SCI论文32篇，在审SCI论文2篇，其中包括1篇Environ. Sci.& Technol.、6篇Atmos. Chem. Phys.、5篇Sci. Tot. Environ.、2篇Geophys. Res. Lett.、8篇Atmos. Environ.；形成专利/软件著作权2项。