广州森林大气中VOCs昼夜变化特征及对O3的影响

Diurnal Variations of VOCs and Relative Contribution to Ozone in Forest of Guangzhou

挥发性有机物化合物(VOCs)是大气光化学过程的重要前驱物,对大气中的臭氧(O)3有重要影响。文章对广州市花都区王子山森林公园大气中VOCs的昼夜变化特征进行了分析,并且评估了其对大气中O3的相对贡献。共定性和定量了21种VOCs,其中1,2,4-三甲基苯(21.50±32.90)μg/m3、甲基环戊烷(20.40±23.30)μg/m3和异戊二烯(14.90±39.20)μg/m3浓度最高。对于大多数VOCs来说,活性VOCs与相对惰性的VOCs表现出相反的昼夜变化特征,这反映了大气光化学反应对于VOCs的影响。采用Propy-Equiv浓度对大气VOCs对O3的影响评估结果表明,该地区大气VOCs对O3贡献的大小为:烯烃>苯系物>烷烃。

Volatile organic compounds （VOCs） as the important precursors during atmospheric photochemical reaction process have greatly effect to concentration of atmospheric ozone. Diurnal variations of VOCs were determined and contributions to O3 were evaluated in the Prince Hill Forest Park, Huadu District of Guangzhou. Twenty one VOCs were qualified and quantified, in which 1, 2, 4-trimethylbenzene followed by methylcyclopentane and isoprene have high concentrations. For most of the VOCs, highly reactive VOCs and other inactive VOCs showed different diurnal concentration variations, which reflected the importance of atmospheric photochemical reaction to the concentrations of VOCs. In addition, Propy-Equival concentrations were used to evaluate the contributions of VOCs to O3. Results showed that the contribution of VOCs to O3 were alkenes, benzene series and alkanes.