Soot大气化学演化过程及其混合气溶胶形成机制研究

近年来我国大气污染事件频发，高浓度O3和细粒子污染成为严重环境问题，作为气溶胶重要组份的黑碳气溶胶污染也日益加重。黑碳气溶胶对空气质量、气候变化和大气化学具有重要作用，但目前对soot的大气化学演化及其在大气化学过程中作用研究不足。本项目拟用漫反射傅立叶变换红外光谱、流动管反应器和外场观测设备等手段开展soot大气化学演化过程及其混合气溶胶形成机制研究。通过考察soot对大气化学过程的影响，阐明soot对SO2、NO2等大气非均相转化过程和对吸附态或溶液中硝酸盐光解的影响、影响机制、潜在转化途径，以及这种影响所带来的对其他物种大气转化的进一步影响等，澄清soot对大气氧化性、大气二次粒子和O3形成等可能作用，进而揭示soot大气化学演化过程及其混合态形成机制。此研究可丰富对大气非均相反应认识，有助于探索大气污染事件中气溶胶和O3形成机制，也有助于为我国大气污染控制和决策制定提供重要科学依据

In recent years in China, photochemical pollution and haze episodes have occurred more frequently. High levels of ozone and atmospheric fine particles have become serious environmental problems, and as a major component of atmospheric aerosol particles, soot (black carbon aerosol) pollution shows an increasing trend. Soot plays an important role in human health, air quality, climate change and atmospheric chemistry. However, a little concern has been paid to atmospheric chemical evolution of soot and its role in atmospheric chemical processes up to now. Here we study atmospheric chemical evolution of soot and formation mechanism of its mixed aerosol by using various measurement techniques and monitoring instruments such as diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and flow tube reactor. Based on the investigations on various atmospheric chemical processes in the presence of soot, we will elucidate the effects of soot on the heterogeneous conversion processes of atmospheric trace gases such as SO2 and NO2 on mineral dust surfaces and the photolysis processes of adsorbed nitrate or nitrate solution, explore the influence mechanisms, potential heterogeneous conversion pathways, and its further influences on the conversions of other atmospheric species, clarify possible roles in atmospheric oxidation capacity and the formation of atmospheric secondary particle and ozone, and its potential impacts on air pollution, and finally reveal the atmospheric chemical evolution processes of soot and the formation mechanisms of its mixing states. This study not only helps to further understand the heterogeneous reaction of atmospheric aerosol, towards a more comprehensive understanding of the atmospheric chemical processes of atmospheric trace gases, but also helps to explore the formation mechanisms of atmospheric aerosols and ozone during air pollution episodes. This study also provides important information for the government to formulate air pollution control strategy and policy.