中文关键词
挥发性有机物(VOCs)浓度特征臭氧生成潜势(OFP)·OH损耗率化学反应活性 英文关键词volatile organic compounds(VOCs)concentration characteristicsozone formation potential(OFP)·OH loss ratechemical reactivity |
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中文摘要 |
2019年对沈阳市大气挥发性有机物(VOCs)开展了为期1 a的观测,并对得到的53种物种进行浓度特征以及反应活性的研究.结果表明,观测期间沈阳市VOCs平均浓度为65.33 μg·m-3,烷烃、烯烃和芳香烃质量分数分别为62.44%、16.52%和19.32%.浓度排名前10的物种主要是C3~C5的烷烃、烯烃和部分芳香烃,累计占VOCs总浓度的64.13%.大气中烷烃、烯烃和芳香烃浓度均表现为双峰型的日变化特征,峰值分别出现在06:00~08:00和19:00~20:00,最低点出现在14:00~15:00;月变化上,该地ρ(VOCs)分别在12月和5月达到最高值(136.44 μg·m-3)和最低值(35.61 μg·m-3);VOCs表现出明显的季节变化特征,即冬季 > 秋季 > 夏季 > 春季,且烷烃、烯烃和芳香烃均随季节表现出增加趋势.通过特征值甲苯/苯(T/B)研究发现,沈阳春季VOCs主要来源于交通源和采暖源,夏季主要来源机动车尾气以及溶剂挥发,秋冬季主要受生物质燃烧和煤燃烧等排放源的影响.通过对反应活性分析,燃烧源是沈阳市控制臭氧污染的关键,丙烯、乙烯和1-己烯是沈阳市大气VOCs中反应活性最高的物种. |
英文摘要 |
The atmospheric volatile organic compounds (VOCs) in Shenyang were observed in 2019, and the concentration characteristics and reactivity of 53 species were studied. The results showed that the average concentration of VOCs was 65.33 μg·m-3, and the proportions of alkanes, olefins, and aromatics were 62.44%, 16.52%, and 19.32%, respectively. The top ten species of VOCs were primarily C3-C5 alkanes, olefins, and some aromatics, accounting for 64.13% of the total VOCs. The concentrations of alkanes, alkenes, and aromatics in Shenyang showed a bimodal diurnal variation trend, with the peak values at 06:00-08:00 and 19:00-20:00 and the lowest values at 14:00-15:00. The highest (136.44 μg·m-3) and the lowest (35.61 μg·m-3) ρ(VOCs) occurred in December and May, respectively. The concentrations of VOCs showed an obvious seasonal variation:winter > autumn > summer > spring. In addition, alkanes, olefins, and aromatics showed an increasing trend with the seasons. Through the value of toluene/benzene (T/B), it was found that VOCs in Shenyang mainly come from traffic and combustion sources in spring, vehicle exhaust and solvent volatilization in summer, and biomass combustion and coal combustion in autumn and winter. It was found that combustion sources were the key to controlling ozone pollution in Shenyang, and propylene, ethylene, and 1-hexene are the most reactive species in atmospheric VOCs in Shenyang based on the analysis of reaction activity. |
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