Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), Department of Environmental Science and Engineering, Institute of Atmospheric Sciences, Fudan University, Shanghai 200433, China.
Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), Department of Environmental Science and Engineering, Institute of Atmospheric Sciences, Fudan University, Shanghai 200433, China.
J Environ Sci (China). 2018 Sep;71:99-107. doi: 10.1016/j.jes.2017.10.011. Epub 2017 Nov 8.
The α-pinene ozonolysis under the different environmental conditions were observed in a smog chamber. The second-order rate constant (k) was determined to be (7.25±0.06)×10-cm/(molecule·sec) under 20% of relative humidity (RH) and room temperature. RH showed a marked influence on the α-pinene ozonolysis. The value of k increased with RH increase, which was 1.6 times faster at RH=80% than that at RH=20%. Additionally, the value of k apparently changed in the presence of the aerosol particles. The diesel soot increased the k value. The fly ash prohibited the reaction, however, HSO-treated fly ash promoted the reaction. The information of products gained using FT-IR and SPAMS showed that pinonic acid, 10-hydroxy-pinonic acid and pinic acid could be generated during the α-pinene ozonolysis. Water molecules could take part in the formation of the products, and play a vital role in the degradation of α-pinene. The atmospheric residence time calculation showed that the ozonolysis in the atmosphere is an important way of the α-pinene consumption as compared to that reacted with OH during daytime. The results suggested that the degradation of α-pinene via the ozonization in the atmosphere may be affected greatly by RH, as well as the presence of aerosol particles. The ozonolysis reaction may be an important way of the α-pinene consumption during daytime.
在烟雾箱中观察了不同环境条件下的α-蒎烯臭氧分解反应。在 20%相对湿度（RH）和室温下，确定其二级反应速率常数（k）为（7.25±0.06）×10-16cm3/（molecule·sec）。RH 对α-蒎烯臭氧分解反应有显著影响。k 值随 RH 的增加而增加，在 RH=80%时比 RH=20%时快 1.6 倍。此外，k 值在气溶胶颗粒存在下明显发生变化。柴油烟尘增加了 k 值。飞灰抑制了反应，但经过 HSO 处理的飞灰促进了反应。使用 FT-IR 和 SPAMS 获得的产物信息表明，在α-蒎烯臭氧分解过程中可以生成 pinonic 酸、10-羟基-pinonic 酸和 pinic 酸。水分子可以参与产物的形成，并在α-蒎烯的降解中发挥重要作用。大气停留时间计算表明，与白天与 OH 反应相比，大气中的臭氧分解是α-蒎烯消耗的重要途径。结果表明，大气中通过臭氧化降解α-蒎烯可能会受到 RH 和气溶胶颗粒存在的很大影响。臭氧分解反应可能是白天α-蒎烯消耗的重要途径。
