民用燃烧源排放PM_(2.5)中多环芳烃的光化学氧化过程  

Photochemical oxidation of polycyclic aromatic hydrocarbons in PM_(2.5)emitted from residential combustion sources

作　　者：张斌[1] 李丹 沈振兴[1] 徐红梅 何昆 孙健 ZHANG Bin;LI Dan;SHEN Zhen-xing;XU Hong-mei;HE Kun;SUN Jian(School of Energy and Power Engineering,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]西安交通大学能源与动力工程学院,陕西西安710049

出　　处：《中国环境科学》2024年第10期5371-5377,共7页China Environmental Science

基　　金：国家重点研发计划项目(2017YFC0212205);陕西省重点研发计划项目(2022ZDLSF06-07);陕西省自然科学基金重大项目(2016ZDJC-22)。

摘　　要：利用潜在气溶胶质量氧化流动反应器(PAM-OFR)测定了不同民用燃烧源新鲜和老化母体多环芳烃(pPAHs)及含氧多环芳烃(oPAHs)的排放量.结果表明,大气光化学氧化后,pPAHs的排放因子下降了29.5%~82.9%,而oPAHs呈现上升趋势.这表明pPAHs主要通过民用燃烧源直接排放到大气中,可被视作一次有机气溶胶(POA),oPAHs由大气中的有机物光氧化生成,被视为二次有机气溶胶(SOA).生物质燃烧过程中pPAHs老化排放因子的平均下降率(73.2%)明显高于煤(56.2%),表明与煤相比生物质燃烧排放的pPAHs在光化学氧化中更具发生化学反应的潜力,从而生成氧化程度更高的物质.研究还表明大气光化学氧化过程会导致oPAHs/pPAHs比值有明显的增加,这说明了pPAHs与·OH反应生成oPAHs的二次反应机理.The emissions of fresh and aged parent polycyclic aromatic hydrocarbons(pPAHs)and oxygenated polycyclic aromatic hydrocarbons(oPAHs)from different residential combustion sources were determined using a potential aerosol mass oxidation flow reactor(PAM-OFR).The results showed that the emission factors of pPAHs decreased by 29.5%~82.9%after atmospheric photochemical oxidation,while oPAHs had an increasing trend.The results demonstrated that pPAHs were emitted directly into the atmosphere through residential combustion sources and were regarded as primary organic aerosol(POA),while oPAHs were generated by photochemical oxidation of organic matter in the atmosphere and were regarded as secondary organic aerosol(SOA).During stimulated photochemical aging,the average decrease of emission factor for pPAHs in biomass burning(73.2%)was significantly higher than that from coal combustion(56.2%),representing that pPAHs emitted from biomass burning have a higher photochemical reaction potential to produce more oxidized substances compared to coal.The present study also showed that the stimulated atmospheric photochemical oxidation process led to a significant increase in the oPAHs/pPAHs ratio and demonstrated a secondary reaction mechanism of pPAHs reacting with hydroxyl radical(·OH)to produce oPAHs.

关 键 词：光化学氧化 多环芳烃(PAHs) 民用燃烧源 二次形成机理 

分 类 号：X513[环境科学与工程—环境工程]