山东地区大气PM2.5和PM1.0化学组成、混合状态及光学特性研究

In Shandong region, the coal-fired power plants and industries are rather concentrated and the total emissions of SO2, NOx ，particulate matter and element carbon are in the top level in China. As a result, this region suffers from severe fine particulate matter pollution. Recent studies have suggested that the large amount of element carbons emitted from fossil fuel combustion and biomass burning strongly absorb the solar radiation and the warming effect can completely or partly neutralize the cooling effect from non-light-absorbing aerosol components. Furthermore, the element carbons mostly exist in the form of internal or core-coated mixture with other components, which has led to enhanced absorption and caused net positive radiation forcing. In this study, we propose to conduct field measurements in representative areas in Shandong region to measure the absorption and scattering coefficients of fine aerosols, mass concentrations, size distributions and mixing states of major aerosol chemical components in PM2.5 and PM1.0, together with gas and meteorological parameters in real-time by using advanced measuring techniques. The contributions of PM2.5 and PM1.0 chemical components to the absorption and scattering coefficients of fine particles will be investigated and the influences of mixing state of element carbons to the optical properties of fine particles will be also analyzed. This study aims to obtain comprehensive understanding of chemical composition, mixing state and optical properties of fine particles in such a region located with concentrated coal-fired power plants and industries in China. The results will provide scientific basis for evaluating the climatic effect of anthropogenic aerosols and for making corresponding policy to control the fine particulate matter pollution.

山东地区燃煤电厂与工业密集，SO2、NOx、颗粒物与元素碳的排放量居全国前列，大气细颗粒物污染十分严重。国际最新研究表明，化石燃料与生物质燃烧排放的大量元素碳具有强烈的吸光作用，其升温效应可全部或部分抵消非吸光组分的冷却效应；元素碳常与其它组分以内混或"核-壳"混合的形式存在，从而显著增强气溶胶的吸光作用并产生净的正辐射强迫。本项目拟在山东典型地区开展观测实验，利用先进测量手段对大气细粒子的光吸收与散射系数、PM2.5与PM1.0主要化学成分的质量浓度、粒径分布与混合状态、相关气体与气象参数等进行在线测量，研究PM2.5与PM1.0主要化学成分对细粒子光吸收与散射系数的贡献，分析元素碳混合状态对细粒子光学特性的影响。本研究旨在全面理解我国燃煤与工业密集地区大气细粒子的化学组成、混合状态及光学特性，研究结果可为评估该地区人为源气溶胶的气候效应及制定细颗粒物控制对策提供理论依据。

本项目开展了如下几方面的工作：1）在山东典型城市地区（济南）、郊区地区（禹城）、高山地区（泰山）开展强化观测实验，采集PM2.5和PM1样品，分析和比较各个地区大气PM2.5和PM1的化学组成，同时观测气溶胶的光学性质，探讨了山东典型地区气溶胶光学性质特征和影响因素及细颗粒物主要化学成分和细颗粒物消光系数的相关性及对细颗粒物消光系数的贡献。2）在山东沿海地区（砣矶岛），开展为期一个月的强化观测实验，结合气象因素，分析沿海背景点大气PM2.5和PM1的化学组成及光学性质特征，探讨了长距离输送源与当地源的贡献。3）选取济南地区典型重污染天气，采用单颗粒气溶胶质谱仪对细颗粒物化学成分进行质谱分析，探讨了灰霾过程中气溶胶混合状态及对灰霾形成过程的贡献。发表SCI文章6篇。.综合，本研究已取得了预期的主要成果，完成了申报既定任务。