衡水夏季典型时段VOCs污染特征及O3污染过程分析

选取臭氧（O₃）污染高发的7月为夏季典型月,采用自动观测设备,从前体物VOCs的浓度水平及O₃生成潜势（OFP）,前体物、气象因素与O₃相关性等多方面研究了衡水市O₃污染影响因素,并剖析了一次典型的O₃污染过程,以期为衡水市夏季O₃污染防治提供科学参考。研究结果表明：衡水市VOCs主要组分浓度占比为烷烃 > 烯烃 > 芳香烃 > 乙炔,主要组分对总OFP的贡献为烯烃 > 芳香烃 > 烷烃 > 乙炔;O₃与前体物VOCs、NO₂存在负相关性,与温度存在正相关性;相对湿度低于48%时,O₃和相对湿度呈负相关性,相对湿度高于48%时,O₃和相对湿度呈正相关性;气团中VOCs化学组成稳定性较低,平均VOCs最大增量反应活性（MIR）较低,为4.855gO₃/gVOCs;衡水市7月2—4日重度污染过程受本地生成和区域传输叠加影响。

Analysis of VOCs Pollution Characteristics and O3 Pollution Process in the Typical Summer Period of Hengshui

July was chosen as the typical summer month due to high incidence of O₃ pollution.The ratio of maximum ozone formation potential(OFP)to volatile organic compounds (VOCs),the correlation between O₃ and precursors and meteorological factors were analyzed,a typical ozone pollution process and the sensitivity of ozone formation control were also discussed to provide scientific basis for the prevention and control of O₃ pollution in Hengshui.The results showed that the concentration of each species of VOCs was in the order of alkanes > olefins > aromatics > acetylene,contribution of each species to total OFP was in the order of olefins > aromatics > alkanes > acetylene.There was a negative correlation between O₃ concentration with precursors VOCs and NO₂,and a positive correlation with temperature.When the relative humidity was lower than 48%,the correlation between O₃ and relative humidity was negative;when the relative humidity was higher than 48%,the correlation between O₃ and relative humidity was positive.The maximum incremental reaction activity of VOCs was low,and the average MIR was 4.855 g O₃/gVOCs.The heavy pollution process in July 2-4 in Hengshui was mainly affected by the superposition of local generation and regional transmission.