2,3-二羟基-4-氧代戊酸的羟基非均相氧化
Heterogeneous oxidation of secondary organic tracers of toluene by hydroxyl radicals
申萍 1曹罡 1朱荣淑1
作者信息
- 1. 哈尔滨工业大学(深圳)土木与环境工程学院,深圳市有机物污染防控重点实验室,深圳,518055
- 折叠
摘要
2,3-二羟基-4-氧代戊酸(2,3-dihydroxy-4-oxopentanoicacid,DHOPA)是甲苯SOA的独特有机示踪物,为评价DHOPA的大气稳定性及其对源解析准确性的影响,本文在大气烟雾箱中研究了 DHOPA纯物质气溶胶和甲苯SOA中的DHOPA气溶胶在不同实验条件下的羟基非均相氧化过程,考察了 SOA生成条件(种子气溶胶和VOC0/NOx比值)和SOA中共存组分对SOA-(DHOPA)的非均相氧化的影响.实验结果表明,在(24.7±1.5)℃、RH=73％±2％条件下,DHOPA与·OH非均相氧化反应的有效速率常数在4.37×10-13-1.47×10-12 cm3·s-1·molecule-1范围内.在典型的大气平均羟基浓度下,DHOPA的有效寿命约为6.27-17.62 d.若同时考虑·OH和O3的氧化作用,5 d后将会有28％—71％的DHOPA被氧化,本研究得到的DHOPA衰减曲线为源解析准确性的校正提供了科学依据.
Abstract
2,3-dihydroxy-4-oxopentanoic acid(DHOPA)is a unique organic tracer of toluene SOA.In order to evaluate the atmospheric stability of DHOPA and its impact on the accuracy of source apportionment,this paper studied the heterogeneous oxidation process of hydroxyl in the pure substance aerosol of DHOPA and the DHOPA aerosol in toluene SOA under different experimental conditions in an atmospheric smoke chamber.The effects of SOA formation conditions(seed aerosol and VOC0/NOx ratio)and coexisting components in SOA on heterogeneous oxidation of SOA-(DHOPA)were investigated.The experimental results show that the effective rate constant of the heterogeneous oxidation reaction of DHOPA with OH is 4.37×10-13-1.47×10-12 cm3·molecule-1·s-1 at(24.7±1.5)℃ and RH=73％±2％.Under typical atmospheric average hydroxyl concentration,the effective life of DHOPA is about 6.27-18.24 days.If the oxidation of·OH and O3 is considered at the same time,28％—71％of DHOPA will be oxidized after 5 days.The DHOPA attenuation curve obtained in this study provides a scientific basis for correcting the accuracy of source apportionment.
关键词
甲苯SOA/有机示踪物/·OH/非均相氧化/源解析Key words
toluene SO A/secondary organic tracer/OH/heterogeneous oxidation/source apportionment引用本文复制引用
出版年
2024
NETL
NSTL
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