SOA formation from photooxidation of naphthalene and methylnaphthalenes with m-xylene and surrogate mixtures
SOA formation from photooxidation of naphthalene and methylnaphthalenes with m-xylene and surrogate mixtures
复制标题
DOI：
10.1016/j.atmosenv.2018.02.051
复制
发表时间：
2018-05
影响因子：
5
通讯作者：
Chia‐Li Chen;Lijie Li;P. Tang;D. Cocker
中科院分区：
文献类型：
--
作者：
Chia‐Li Chen;Lijie Li;P. Tang;D. Cocker
目前的模型对城市SOA的形成预测不准确。在复杂的城市大气中，多种人为挥发性有机物之间的相互作用是形成SOA的关键。在UCR CE-CERT环境箱中，研究了萘、1-甲基萘和2-甲基萘以及多环芳烃（PAHs）与间二甲苯或大气代用品混合物在城市相关低NOx和极低NOx（H2O2）条件下光氧化产生的二次有机气溶胶（SOA）。添加间二甲苯抑制SOA的形成从个人PAH前体。在替代混合物光氧化过程中观察到类似的抑制SOA形成的效果，表明气相化学反应对SOA形成的重要性。不同PAH-间二甲苯混合物的SOA增长速率与初始[HO2]/[RO2]比呈强相关，但与初始间二甲苯/NO比呈负相关。减少SOA的形成，观察到增加间二甲苯/多环芳烃的比例和增加初始间二甲苯/NO的比例。SOA的化学组成特征，如f 44与f 43、H/C比、O/C比和碳的氧化态OS ′ c，与连续老化一致，SOA表现出两种前体的特征。从多环芳烃的SOA形成也被抑制在一个大气的替代混合物相比，从个别多环芳烃形成的SOA，表明大气反应性直接影响SOA的形成从多环芳烃。
SOA formation is not well predicted in current models in urban area. The interaction among multiple anthropogenic volatile organic compounds is essential for the SOA formation in the complex urban atmosphere. Secondary organic aerosol (SOA) from the photooxidation of naphthalene, 1-methylnaphthalene, and 2-methylnaphthalene as well as individual polycyclic aromatic hydrocarbons (PAHs) mixed with m-xylene or an atmospheric surrogate mixture was explored in the UCR CE-CERT environmental chamber under urban relevant low NO x and extremely low NO x (H 2 O 2) conditions. Addition of m-xylene suppressed SOA formation from the individual PAH precursor. A similar suppression effect on SOA formation was observed during the surrogate mixture photooxidation suggesting the importance of gas-phase chemical reactivity to SOA formation. The SOA growth rate for different PAH-m-xylene mixtures was strongly correlated with initial [HO 2]/[RO 2] ratio but negatively correlated with initial m-xylene/NO ratio. Decreasing SOA formation was observed for increasing m-xylene/PAHs ratios and increasing initial m-xylene/NO ratio. The SOA chemical composition characteristics such as f 44 versus f 43, H/C ratio, O/C ratio, and the oxidation state of the carbon OS¯ c were consistent with a continuously aging with the SOA exhibiting characteristics of both individual precursors. SOA formation from PAHs was also suppressed within an atmospheric surrogate mixture compared to the SOA formed from individual PAHs, indicating that atmospheric reactivity directly influences SOA formation from PAHs.