Ionic Strength Effect Alters the Heterogeneous Ozone Oxidation of Methoxyphenols in Going from Cloud Droplets to Aerosol Deliquescent Particles
Ionic Strength Effect Alters the Heterogeneous Ozone Oxidation of Methoxyphenols in Going from Cloud Droplets to Aerosol Deliquescent Particles
复制标题
离子强度效应改变甲氧基酚从云滴到气溶胶潮解颗粒的非均相臭氧氧化
DOI：
10.1021/acs.est.0c03648
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发表时间：
2020
影响因子：
11.4
通讯作者：
Gligorovski Sasho
中科院分区：
文献类型：
--
作者：
Mekic Majda;Wang Yiqun;Loisel Gwendal;Vione Davide;Gligorovski Sasho
甲氧基酚是大气木材烟雾污染最丰富的生物标记示踪剂之一。大气氧化剂（臭氧，OH）与甲氧基酚的反应可能有助于形成二次有机气溶胶（SOA）。在这里，我们首次使用成熟的垂直湿壁流管 (VWWFT) 反应器来评估离子强度 (I)、pH、温度和臭氧浓度对臭氧与乙酰丁香酮 (ACS)（作为代表性甲氧基苯酚化合物）的反应动力学的影响。在酸性大气潮解颗粒的典型 pH 值固定为 3 的条件下，通过 Na2SO4 调节 I= 0.9 M，O3 的吸收系数 (γ) 增加了 2 个数量级，从纯盐溶液 (Na2SO4) 上的 γ = (5.0 ± 0.8) × 10–8 到 ACS 和 Na2SO4 混合物上的 γ = (6.0 ± 0.01) × 10–6。不同pH值下O3吸收系数的比较表明，反应动力学强烈依赖于ACS酚基的酸性。观察到的气相臭氧与 ACS 的不同反应性对云滴的稀水相和负载无机盐的气溶胶潮解颗粒吸收臭氧有影响，并且它可以影响大气中 SOA 的形成。
Methoxyphenols are one of the most abundant classes of biomarker tracers for atmospheric wood smoke pollution. The reactions of atmospheric oxidants (ozone, OH) with methoxyphenols can contribute to the formation of secondary organic aerosols (SOA). Here, for the first time, we use the well-established vertical wetted wall flow tube (VWWFT) reactor to assess the effect of ionic strength (I), pH, temperature, and ozone concentration on the reaction kinetics of ozone with acetosyringone (ACS), as a representative methoxyphenol compound. At fixed pH 3, typical for acidic atmospheric deliquescent particles, and atI= 0.9 M adjusted by Na2SO4, the uptake coefficient (γ) of O3increases by 2 orders of magnitude from γ = (5.0 ± 0.8) × 10–8on neat salt solution (Na2SO4) to γ = (6.0 ± 0.01) × 10–6on a mixture of ACS and Na2SO4. The comparison of the uptake coefficients of O3at different pH values indicates that the reaction kinetics strongly depends on the acidity of the phenolic group of ACS. The observed different reactivity of gas-phase ozone with ACS has implications for ozone uptake by the dilute aqueous phase of cloud droplets and by aerosol deliquescent particles loaded with inorganic salts, and it can affect the formation of SOA in the atmosphere.