佛山市挥发性有机化合物污染特征及其关键组分分析

Analysis of the Characteristics and Key Components of Volatile Organic Compounds in Foshan

本研究基于2022年佛山市大气综合观测场的挥发性有机化合物(VOCs)在线监测数据,分析了佛山市大气VOCs浓度水平和化学组成等特征,并通过计算各组分臭氧生成潜势(OFP)和二次有机气溶胶生成潜势(AFP),识别了影响臭氧和颗粒物污染的关键组分。结果显示,佛山市VOCs平均浓度为28.26 ppbv,其中烷烃含量最高,占比60.0%,其次是芳香烃。春季VOCs平均浓度最高,其次是冬季、秋季和夏季;日变化呈“U”型分布特征,夜间高白天低。间/对-二甲苯、甲苯、邻-二甲苯和乙苯是影响佛山市臭氧和二次有机气溶胶的共同的关键物种,应加大对这些物种的协同减排。

In this study,the characteristics of volatile organic compounds(VOCs)including abundance and composition were analyzed based on the field measurement conducted at an atmospheric comprehensive observation site in Foshan in 2020.In addition,the ozone formation potential(OFP)and the secondary organic aerosol formation potential(AFP)of VOC components were calculated to identify the key species affecting ozone and particulate matter pollution.The results showed that the mean mixing ratio of measured VOCs was 28.26 ppbv,with the largest contribution from alkanes accounting for 60.0%,followed by aromatics.N-butane,propane and toluene were the top three abundant VOC species.The mean mixing ratio of measured VOCs was the highest in spring,followed by winter,autumn and summer.The diurnal variation of VOCs showed a U-shaped distribution,which was higher at night and lower during the day.Among all measured VOC species,m/p-xylene,toluene,o-xylene and ethylbenzene played an essential role in the photochemical formation of ozone and secondary organic aerosols,indicating that more efforts should be made to reduce the emission of these key species.