中国环境科学

作者：谈琰, 张玉佳, 刘晓, 刘亭, 马子轸, 张华伟, 李顺诚

单位：1. 青岛理工大学环境与市政工程学院, 山东 青岛 266520;2. 香港科技大学(广州)功能枢纽地球与海洋大气科学学域, 广东 广州 511453

关键词：异戊二烯,臭氧,烟雾箱,氧化产物

基金：山东省自然科学基金资助项目(ZR202111290185)

A chamber experiment was conducted simulate the nighttime ozone oxidation process of isoprene. The concentration changes of gas-phase products in the isoprene-ozone reaction system were monitored in real-time using proton transfer reaction time-of-flight mass spectrometry (PTR-TOF-MS). Furthermore, the production process of secondary organic aerosols (SOA) was assessed in real-time through scanning mobility particulate size spectrometry (SMPS). The findings revealed that under the conditions of a reaction temperature of (298 ±1) K and a relative humidity of 30%, isoprene was consumed by ozone, resulting in the formation of SOA. The concentration of SOA peaked at 3.14µg/m3 approximately 4 hours into the reaction. The main gas-phase products of the nighttime ozone oxidation reaction of isoprene were oxygenated volatile organic compounds (OVOCs) ranging from C1 ~ C4, including formaldehyde (HCHO), formic acid (CH2O2), acetic acid (C2H4O2), acetone (C3H6O), propionic acid (C3H6O2), methacrolein (MACR), methyl vinyl ketone (MVK), and methacrylic acid (C4H6O2), and the yields of these products varied with the ratio of ozone to isoprene. Notably, HCHO and MACR + MVK exhibited the highest yields among all oxidation products. When the ozone/isoprene ratio ranged from 0.5 to 6.8, the yield ranges were 17.0% to 35.6% for HCHO and 59.3% to 89.5% for MACR + MVK. Additionally, NO2 was found to inhibit the production of HCHO and MACR + MVK, while other OVOCs displayed a mild negative correlation with increasing NO2 concentrations. The nighttime oxidation of isoprene plays a significant role in the formation of OVOCs and SOA.

来源：2024年第11期

《中国环境科学》期刊编辑部

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