Atmospheric chemistry of nitrous acid and its effects on hydroxyl radical and ozone at the urban area of Beijing in early spring 2021.
Atmospheric chemistry of nitrous acid and its effects on hydroxyl radical and ozone at the urban area of Beijing in early spring 2021.
复制标题
DOI：
10.1016/j.envpol.2022.120710
复制
发表时间：
2022-11
影响因子：
8.9
通讯作者：
Wenqian Zhang;Shengrui Tong;Deng Lin;Fangjie Li;Xinran Zhang;Lili Wang;D. Ji;G. Tang;Zirui Liu;B. Hu;Maofa Ge
中科院分区：
文献类型：
--
作者：
Wenqian Zhang;Shengrui Tong;Deng Lin;Fangjie Li;Xinran Zhang;Lili Wang;D. Ji;G. Tang;Zirui Liu;B. Hu;Maofa Ge
亚硝酸（HONO）由于对羟基自由基的重要贡献而受到广泛关注。NO2的非均相反应是HONO的重要来源，其反应机理受多种因素的影响，如气态NO2浓度、表面吸附水、相对湿度和温度等。虽然实验室研究已经证实了温度对NO2非均相反应的影响，但很少有现场观测报告。我们在2021年早春进行了现场观测，当时温度范围很广（−0.1-24.7 °C）。得到了北京城区HONO及相关污染物的浓度。HONO的小时平均浓度为4.87 ppb，平均值为1.48 ± 1.09 ppb。结合箱模型和RACM 2机理，我们发现在本实验中NO2的非均相反应存在一个最佳温度（约10 °C）。当考虑最佳温度的促进作用时，NO2的非均相反应对HONO的贡献可增加10%。这一结果将为建立大气中HONO化学的精确模式提供必要的信息，特别是在温度变化较大的某些时期或地区。NO2的非均相反应是HONO的重要来源，对模拟HONO的贡献率为63-76%。HONO光解是OH自由基最重要的生成途径，环境HONO浓度是模型模拟评估大气氧化的附带约束。
The atmospheric chemistry of nitrous acid (HONO) has received extensive attention because of its significant contribution to hydroxyl (OH) radicals. Heterogeneous reaction of NO2is an important HONO source, and its reaction mechanism is affected by many factors, such as concentration of gaseous NO2, surface adsorbed water, relative humidity and temperature. Although laboratory studies have confirmed the effect of temperature on heterogeneous reaction of NO2, there are few field observations reporting about it. We have conducted a field observation in the early spring 2021 when the temperature ranges widely (−0.1–24.7 °C). Concentrations of HONO and related pollutants at the urban area of Beijing are obtained. The hourly averaged HONO concentration reaches 4.87 ppb with a mean value of 1.48 ± 1.09 ppb. Combined with box model and RACM2 mechanism, we found an optimal temperature (∼10 °C) existing for heterogeneous reaction of NO2during this measurement. When considering the promotion effect of optimal temperature, the contribution of heterogeneous reaction of NO2to HONO can increase by 10%. This result will provide essential information for developing an accurate model of HONO chemistry in the atmosphere especially for certain periods or regions with temperature changing largely. Moreover, heterogeneous reaction of NO2is the vital source of HONO, contributing 63–76% to simulated HONO during this measurement. Note that HONO photolysis is the most important formation pathway of OH radicals, and ambient HONO concentration is the obbligato constraint for evaluating atmospheric oxidation by model simulations.