State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510 640, China.
University of Chinese Academy of Sciences, Beijing, China.
Environ Sci Technol. 2020 Sep 15;54(18):11079-11086. doi: 10.1021/acs.est.0c02627. Epub 2020 Sep 2.
Polycyclic aromatic hydrocarbons (PAHs) as constituents of urban grime and indoor surfaces can impact the photochemical conversion of nitrogen dioxide (NO) to nitrous acid (HONO) thereby impacting the oxidation capacity of the atmosphere. In this study we investigate the effect of relative humidity (RH%), light intensity, and NO concentrations on uptake coefficients (γ) of NO on solid film consisting of fluorene (FL) and a mixture of FL and NaSO as a proxy for urban and indoor grime at ambient pressure and temperature. γ(NO) on solid FL increased markedly from (5.7 ± 1.7) × 10 at 0% RH to (4.6 ± 1.0) × 10 at 90% RH. The NO to HONO conversion yield, (ΔHONO/ΔNO)%, increases with RH from 40% at 0% RH up to 80% at 60-90% RH, indicating that the water molecules favor the formation of HONO up to 60% RH. These results suggest that the heterogeneous photochemical reaction of NO on FL and FL/NaSO can be an important source of HONO in the urban environment and indoor atmosphere and should be considered in photochemical models.
多环芳烃 (PAHs) 作为城市污垢和室内表面的组成部分，可以影响二氧化氮 (NO) 向亚硝酸 (HONO) 的光化学转化，从而影响大气的氧化能力。在这项研究中，我们研究了相对湿度 (RH%)、光强和 NO 浓度对固体薄膜上的 NO 吸收系数 (γ) 的影响，该固体薄膜由芴 (FL) 和 FL 与 NaSO 的混合物组成，作为城市和室内污垢的代表，在环境压力和温度下。在 0% RH 时，固体 FL 上的 γ(NO) 从 (5.7 ± 1.7) × 10 显著增加到 90% RH 时的 (4.6 ± 1.0) × 10。NO 向 HONO 的转化率，(ΔHONO/ΔNO)%，随着 RH 从 0% RH 时的 40%增加到 60-90% RH 时的 80%，表明水分子有利于 HONO 的形成，直到 60% RH。这些结果表明，NO 在 FL 和 FL/NaSO 上的非均相光化学反应可能是城市环境和室内大气中 HONO 的一个重要来源，应在光化学模型中加以考虑。
