摘要
采用罐采样/气相色谱-氢离子火焰检测器/质谱检测器联用法对银川市2021年7-9月大气中116种VOCs进行手工监测,分析其污染特征、臭氧生成潜势和来源。结果表明:观测期间,银川市共检出81种VOCs,总挥发性有机物的平均体积浓度值为58.4×10-9,各主要组分浓度由大到小依次为:含氧挥发性有机物(OVOCs)(42.5%)、烷烃(32%)、卤代烃(7.7%)、芳香烃(6.8%)、烯烃(6.6%)。银川市主要非甲烷烃类体积浓度水平处于国内中等水平。加密观测期间,日变化规律呈双峰结构,高浓度主要出现在凌晨0:00-03:00和午后15:00-18:00,大气光化学反应二次生成对醛酮类有较大贡献,昼间醛酮类物质表现出与臭氧浓度一致的变化特征。臭氧生成潜势分析银川市夏季VOCs臭氧生成潜势为503.1μg/m3,其中醛酮类含氧VOCs(52.4%)和芳烃(19.1%)是主要贡献组分。利用示踪法和比值法推断,液化石油气(LPG)燃烧、机动车尾气和工业排放是非甲烷烃类的主要来源。
In order to evaluate pollution characteristics,ozone formation potential(OFP)and analyze potential sources of VOCs in Yinchuan from July to September in 2021,116 VOCs species were measured by SUMMA tank sampling-GC-FID/MS analysis method.The results showed that a total of 81 kinds of species were detected and the averaged volume fraction of TVOCs was 58.4x10-9.The major components were oxygen-containing VOCs,alkanes,halogenated hydrocarbon,aromatics and alkenes,which accounted for 42.4%,32.0%,7.7%,6.8%and 6.6%.The volume concentration of 57 critical ozone precursors was generally at the intermediate level in China.The diurnal cycles of VOCs reveal“bimodal”distribution.The higher concentration of VOCs observed at 00:00-03:00 in the midnight and 15:00-18:00 in the afternoon.The carbonyls were manly affected by the secondary formation from the atmospher ic photochemical process.The diurnal variation of carbonyls concentrations was consistent with the trend of 03.Furthermore,maximum incremental reaction(MIR)analysis was used to estimate ozone formation(OFP)of VOCs.The results showed that the calculated OFPs in Yinchuan were 503.ljxg/m^(3).Carbonyls and aromatic hydrocarbons were the dominant contributors to OFPs,which accounted for 52.4%and 19.1%to total OFPs,respectively.From the results of tracer analysis and concentration ratios analysis,the non-methane hydrocarbons(NMHCs)pollutants in Yinchuan were mainly contributed by liquefied petroleum gas(LPG),automobiles exhaust and industrial emissions.
作者
司利国
赵涛
杨丽蓉
金玉梅
郭英茹
郭小宁
Si Liguo;Zhao Tao;Yang Lirong;Jin Yumei;Guo Yingru;Guo Xiaoning(Yinchuan Eco-environmental Monitoring Station,Yinchuan Ningxia 750001,China)
出处
《环境与发展》
2023年第2期62-70,共9页
Environment & Development
基金
宁夏自然科学基金项目(项目编号:2022AAC03751)。
关键词
挥发性有机物
污染特征
臭氧生成潜势
OCs
Pollution characteristics:
Ozone formation potentials
