漯河市夏季大气挥发性有机物变化特征和来源解析

Characteristics and Sources of Volatile Organic Compounds(VOCs)in Luohe City During Summer

漯河市是中原城市群重要的节点城市,近年来大气臭氧(O_(3))污染情势严峻.为此,于2022年7月在漯河市开展O_(3)前体物挥发性有机物(VOCs)的在线观测,分析其变化特征并进行来源解析,为O_(3)污染控制提供科学依据.观测期间φ(TVOCs)的均值为(16.49±5.73)×10^(-9).其中,烷烃(33.7%)、含氧有机物OVOC(24.0%)和卤代烃(21.9%)占比前3.源解析结果表明,主要VOCs来源(贡献)分别有天然气(NG)使用(20.1%)、区域输送(14.8%)、溶剂使用(14.2%)、汽油车排放(12.3%)、工业排放(11.6%)、柴油车排放(10.5%)、液化石油气(LPG)使用(9.8%)和植物排放(6.7%).OVOC对臭氧生成潜势(OFP)和自由基损耗速率(L·OH)贡献最大.结果表明,机动车尾气贡献(22.8%)是漯河市VOCs的首要来源,但其它来源复杂且相对均衡,需要制定有针对性的综合防治措施.

Luohe City is an important node city in the Central Plains Urban Agglomeration in China,where the atmospheric ozone(O_(3))pollution situation has been serious in recent years.In order to provide a scientific basis for O_(3) pollution control,the online filed observation of O_(3) precursor volatile organic compounds(VOCs)was carried out in Luohe City in July 2022 to understand their variation characteristics and sources.The mean ratio ofφ(TVOCs)during the observation period was(16.49±5.73)×10^(-9).Among them,alkane(33.7%),oxygenated volatile organic compounds OVOC(24.0%),and halohydrocarbon(21.9%)accounted for the top three.The results from source apportionment showed that the main VOCs sources(contributions)included the natural gas(NG)use(20.1%),regional transport(14.8%),solvent use(14.2%),gasoline vehicle emissions(12.3%),industrial emissions(11.6%),diesel vehicle emissions(10.5%),liquefied petroleum gas(LPG)use(9.8%),and plant emissions(6.7%).OVOC contributed the most to ozone formation potential(OFP)and free radical loss rate(L·OH).The results showed that the contribution of motor vehicle exhaust(>22.8%)was the primary source of VOCs in Luohe City.However,other sources were complex and with comparable contributions,requiring the development of targeted and comprehensive prevention and control measures.