影响异戊二烯大气光解形成二次有机气溶胶的环境因素研究

通过自制的烟雾腔系统研究羟基启动的异戊二烯光解形成二次有机气溶胶(SOA)过程中环境因素的影响.使用气溶胶粒径光谱仪测量了SOA的粒径分布,通过光解实验研究了光照时间、反应物浓度以及CH3ONO浓度对异戊二烯光解形成SOA的影响.结果表明,异戊二烯光解形成的SOA空气动力学直径在0.4 mm～1.4 mm之间,这些粒子的直径小于2.5μm的微细粒子很容易沉积在人体肺泡内,对人体健康产生很大危害;不管是SOA粒子的粒子数浓度还是质量数浓度都随着反应时间的增长、光照强度的增强和反应物浓度的增加而增加.该研究为大气颗粒物排放源的外场测量提供了非常有用的信息.

Effects of Environmental Factors on Secondary Organic Aerosol Formed from Isoprene Atmospheric Photo-oxidation Reactions

The effect of environmental factors on Secondary Organic Aerosol (SOA) formed from hydroxyl radical (OH ·) initiated photooxidation of isoprene were investigated by using a home-made smog chamber.The size distribution of SOA particles from the above reaction were measured using Aerodynamic Particle Sizer spectrometer (APS).The effect of radiation time,reactant concentration,and CH3ONO concentration on SOA formation from isoprene were evaluated by performing photooxidation experiments under varying conditions.Experimental results showed that aerodynamic diameter for SOA detected in isoprene photo oxidation experiments was predominantly in 0.4 mm ～1.4 mm,which were in the form of fine particles with diameters less than 2.5 μm.These fine particulate matters are more easily deposit in the lung of the human being,and do great harm to the health.This paper also highlighted that both the number and mass concentration of SOA particles were increasing with the prolonging of the radiation time,the increasing of light intensity,and the increasing of the reactant concentrations.The results could provide useful information to infer possible emission sources of atmospheric particles in future field measurement.