绍兴城区夏季大气挥发性有机物特征、来源及大气反应活性

Characteristics,sources and atmospheric reactivity of volatile organic compounds in Shaoxing urban during summer

研究了2019年夏季(8月)绍兴城区的烷烃、烯烃、炔烃、芳烃、卤代烃、含氧挥发性有机物(VOCs)、腈7类共98种VOCs的特征、来源及大气反应活性。结果表明,7类VOCs的平均质量浓度由大到小依次为烷烃(24.29μg/m 3)>卤代烃(17.17μg/m 3)>芳烃(15.89μg/m 3)>含氧VOCs(14.72μg/m 3)>烯烃(4.06μg/m 3)>炔烃(1.23μg/m 3)>腈(0.27μg/m 3)。烃、腈和卤代烃白天浓度低,夜间浓度高,含氧VOCs基本上终日保持稳定。白天交通排放的贡献较为显著;夜间除交通排放外,挥发性有机溶剂的使用对绍兴城区夏季VOCs也有重要影响。此外,VOCs在一定程度上受到了长距离气团传输的影响,也存在一定的老化现象。烯烃、芳烃是绍兴城区夏季最具大气反应活性的VOCs。

7 kinds of 98 volatile organic compounds(VOCs),including alkane,alkene,alkyne,aromatic hydrocarbon,halogenated hydrocarbon,oxygen-containing VOCs,and nitrile were investigated in summer(August),2019 to identify the characteristics,sources and atmospheric reactivity of VOCs in Shaoxing urban.Results showed that the average mass concentrations of 7 kinds of VOCs were alkane(24.29μg/m 3)>halogenated hydrocarbon(17.17μg/m 3)>aromatic hydrocarbon(15.89μg/m 3)>oxygen-containing VOCs(14.72μg/m 3)>alkene(4.06μg/m 3)>alkyne(1.23μg/m 3)>nitrile(0.27μg/m 3).Concentrations of hydrocarbon,nitrile and halogenated hydrocarbon were low in the daytime,and high in the nighttime,but those of oxygen-containing VOCs remained stable all over the day.It was confirmed that the main source of VOCs in the daytime was tansportation emissions,but volatile organic solvents usage should not be negligible besides tansportation emissions in the nighttime.In addition,VOCs in Shaoxing urban were affected by long-distance air mass transmission,and there was a certain aging phenomenon.Alkene and aromatic hydrocarbon were the most active VOCs in Shaoxing urban during summer.