大气糖类有机物在雾霾过程中的行为与机制研究

This project focuses on physicochemical characteristics, behavior process, hygroscopic mechanism and tracing applications of sugars in the atmosphere by using field observations and simulation technology. Based on the sugur analysis of the samples associted with the size-segregated particles, the precipitations (fog, rain), aerosol particles before, during and after haze, fog or rain events, we can obtain on size distribution, transport process and hydrolysis products of atmospheric sugars. Based on the experiment of hygroscopicity, we can reveal the influence of sugars on the hygroscopic growth of aerosol particles and build a relationships between the hygroscopicity and the sugar components through quality and quantity. Based on the simulation experiment of biomass burning, we can find the key sugar tracers for different biomass emission and quantify the sources contribution to fog or haze events. In addition, through this project, we can also improve or develop new detection technology for sugars in the atmosphere. Therefore, this project is expected to get an in-depth and multi-aspect insight into atmospheric sugars with great scientific significance for understanding the process and mechanism of atmospheric pollution.

本课题立足大气糖类有机物，采用外场观测与实验室模拟的集成方法，系统研究雾霾天气中糖的理化特征、行为过程、吸湿机制与示踪应用。通过分析大气颗粒物（不同粒径）、大气降水（雾水、雨水）以及雾、霾、雨前、过程中、后的气溶胶颗粒物等样品中糖类的组成与浓度变化，解析其粒径分布、过程转化与水解产物等信息；基于吸湿性实验，揭示大气糖类及水解产物对气溶胶颗粒吸湿增长的影响，建立气溶胶吸湿因子与糖组分间的质和量的关系。通过燃烧模拟实验，提取能够识别不同生物质对应的特征糖类示踪物，进而定量估算排放源对大气雾霾形成的贡献。本课题有望从多角度、深层次地剖析大气糖类有机物，对认识大气污染过程与机理具有重要的科学意义。

本项目为解决糖类化合物在大气环境中的理化行为问题，采用外场观测与实验室模拟的方法，系统研究了大气糖类化合物的来源、大气过程、吸湿机制与示踪应用。通过本研究，获得了不同粒径大气颗粒物中左旋葡聚糖、阿拉伯醇、甘露醇、葡萄糖、蔗糖、果糖、甘露聚糖、中赤藓糖醇、肌醇、半乳糖与阿糖醇等糖类化合物的浓度组成及粒径分布等信息。完善并发展了大气糖类化合物的分析技术，研究了左旋葡聚糖的吸湿机制及与液相氧化过程。应用PCA与PMF方法，找出了生物源排放气溶胶对应的初级糖和糖醇类标志物，以及生物质燃烧气溶胶对应的特征糖苷类示踪物，并根据Lev/Man比值，进一步区分了不同生物质类别。利用这些糖类标志物，结合其在长程传输过程中的大气稳定性，最终揭示了源排放对上海灰霾形成的贡献。通过本课题研究，已发表包括Atmos. Chem. Phys., Atmos. Environ.在内的SCI论文22篇，培养博（硕）士研究生7名。