Effect of aluminium dust on secondary organic aerosol formation in m-xylene/NO_x photo-oxidation  

作　　者：LIU Chang MA QingXin CHU BiWu LIU YongChun HE Hong ZHANG XiaoYe LI JunHua HAO JiMing 

机构地区：[1]Chinese Academy of Meteorological Sciences [2]Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences [3]School of Environment, Tsinghua University

出　　处：《Science China Earth Sciences》2015年第2期245-254,共10页中国科学（地球科学英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.41305116);the National Basic Research Program of China(Grant No.2011CB403401);the Specific Team Fund of Chinese Academy of Meteorological Sciences(Grant No.2010Z002)

摘　　要：As an important anthropogenic volatile organic compound(VOC), m-xylene has attracted numerous attentions due to its potential in secondary organic aerosol(SOA) formation. In this study, effects of aluminium dust seeds(boehmite and alumina) on SOA yield and aerosol size in m-xylene/NOx photo-oxidation were investigated in a 2 m3 smog chamber at 30°C and 50% relative humidity. Compared to the seed-free system, the presence of aluminium seeds resulted in an increase in the SOA yield, and also enhanced the O3 concentration in the chamber. The photolysis of O3 is a major source of OH radical, which is the most important oxidant of m-xylene. The increase in O3 concentration could result in the generation of more OH radicals, and finally contribute to the SOA formation. Seed particles influence the SOA size mainly by acting as condensation nuclei. Semi-volatile organic compounds(SVOCs) were condensed onto these nuclei, resulting in the increase in SOA size. However, when aluminium seeds with high concentrations were introduced into the system, SVOCs that had been condensed onto each particle were dispersed by these seeds, leading to the reduction in aerosol size.As an important anthropogenic volatile organic compound（VOC）, m-xylene has attracted numerous attentions due to its potential in secondary organic aerosol（SOA） formation. In this study, effects of aluminium dust seeds（boehmite and alumina） on SOA yield and aerosol size in m-xylene/NOx photo-oxidation were investigated in a 2 m3 smog chamber at 30°C and 50% relative humidity. Compared to the seed-free system, the presence of aluminium seeds resulted in an increase in the SOA yield, and also enhanced the O3 concentration in the chamber. The photolysis of O3 is a major source of OH radical, which is the most important oxidant of m-xylene. The increase in O3 concentration could result in the generation of more OH radicals, and finally contribute to the SOA formation. Seed particles influence the SOA size mainly by acting as condensation nuclei. Semi-volatile organic compounds（SVOCs） were condensed onto these nuclei, resulting in the increase in SOA size. However, when aluminium seeds with high concentrations were introduced into the system, SVOCs that had been condensed onto each particle were dispersed by these seeds, leading to the reduction in aerosol size.

关 键 词：aerosol xylene chamber aluminium anthropogenic volatile nuclei humidity dispersed oxidant 

分 类 号：X51[环境科学与工程—环境工程]