用于研究大气氧化过程和机制的双反应器烟雾箱的评估和应用

设计并搭建了一个新的双反应器烟雾箱, 用于研究可生成臭氧或二次有机气溶胶(SOAs)的大气氧化过程. 该烟雾箱包括一个绝热的箱体及其内部两个体积为5 m³的氟化乙丙烯(FEP)薄膜反应器, 箱内的温度可以精确控制在-10到40 ℃之间. 利用该烟雾箱研究了光源对丙烯气相氧化机理的影响, 发现相对于传统的黑光灯光源, 采用的多重光源所得到的结果可以与模型更好地匹配. 进行了丙烯和间二甲苯的光氧化的初步实验, 发现该烟雾箱可用于模拟可产生臭氧或SOAs的气相氧化过程, 并可以通过不同初始浓度的对比实验找寻不同物种对反应过程的影响. 间二甲苯在不同NO_x条件下光氧化得到的SOA产率与之前的研究比较符合, 这表明该烟雾箱可以实现气-粒转化过程的模拟. 双反应器可以实现在一个关键条件的存在区别, 而其他条件完全一致的情况下的对比实验, 从而帮助我们进一步理解在大气复合污染过程中起关键作用的因素.

Evaluation and Application of Dual-Reactor Chamber for Studying Atmospheric Oxidation Processes and Mechanisms

A new smog chamber with dual reactors was designed and constructed to study atmospheric oxidation processes that may form ozone or secondary organic aerosols (SOAs). The chamber consists of two 5 m³ fluorinated ethylene propylene (FEP) Teflon-film reactors housed in a thermally isolated enclosure, in which the temperature can be well controlled in the range of -10 to 40 ℃. The influence of the light source on the gasphase oxidation mechanism of propene was investigated. The results showed that multiple ultraviolet (UV) light sources were better than traditional narrow-band black-lamp light sources. Preliminary experiments on propene and m-xylene photo-oxidation processes were performed. The results showed that the dual-reactor chamber can simulate the gas-phase oxidation processes that form ozone or SOAs, and can be used to determine the effects of various species by comparing experiments performed using different initial concentrations. The SOA yield data from m-xylene photo-oxidation under different NO_x conditions were in good agreement with those from previous studies. This proves that the chamber can simulate gas-to-particle conversion processes. The dual reactors have the advantage of enabling experiments to be performed with only one key parameter being changed. This will help us to further understand the role of key factors in complex atmospheric pollution processes.