大气模拟烟雾箱中HONO的表征  

Characterization of the HONO source in an atmosphere simulation chamber

作　　者：赵喆[1] 郝吉明[1] 李俊华[1] 武山[1] 

机构地区：[1]清华大学环境科学与工程系,北京100084

出　　处：《环境科学学报》2008年第12期2465-2469,共5页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金项目(No.20637001);丰田汽车公司资助国际合作项目~~

摘　　要：NO2与H2O在烟雾箱表面生成HONO的异相反应是导致烟雾箱实验数据不确定性增加的主要原因之一,因此,必须对该反应进行表征.本研究采用烟雾箱实验与箱式模型模拟相结合的方法,确定实验系统特有的HONO释放速率.实验在室内烟雾箱实验系统完成,通过NO、NO2沉积实验获得的气态反应物在烟雾箱壁面(Teflon膜)上的沉积速率分别为0.0026h-1及0.0025h-1;光解实验得到NO2的光解速率为0.21min-1,在此基础上利用量子产率、吸收截面积、光谱分布计算出其它6个光解反应的速率常数.将实验获取的速率常数与CB-IV反应机理联合使用建立箱式模拟系统,利用CO-NO实验数据对模拟参数进行优化,得到该系统的HONO的释放速率为1.65×10-5cm3·mol-1·s-1.由此提供了一种表征实验与箱式模型联合使用确定烟雾箱系统HONO释放速率的有效方法.Heterogeneous hydrolysis of NO2 on the chamber wall, leading to HONO formation, has been reported to be the major uncertainty of atmospheric chamber experiments. In this study, laboratory experiments and box simulations are carried out to characterize the background HONO formation rate. The deposition rate of NO and NO2 are 0. 0026 h ^-1 and 0. 0025 h^-1, respectively. Rate constants for the photolysis reactions are calculated using the NO2 photolysis rates （experimentally determined, 0. 21 min^-1 ）, the relative spectral distributions for the light sources, the absorption cross sections and quantum yields. The CB-IV mechanism is used to simulate the CO-NO chamber experiment, and by optimizing the box simulation results with the experimental data, the HONO formation rate is estimated to be 1.65 × 10^ - 5 cm^3 · mol^-1· s^ - 1 for our chamber system.

关 键 词：烟雾箱 HONO 表征 自由基 

分 类 号：X515[环境科学与工程—环境工程]