深圳市中心城区VOCs污染特征与臭氧来源量化分析

Study on VOCs pollution characteristics and quantification of ozone pollution sources in urban areas of Shenzhen

文章利用莲花山生态监测站污染物观测数据与近地面气象数据,分析了2018年9月21日~10月18日深圳市出现连续臭氧(O_(3))污染过程期间,城区挥发性有机物(VOCs)体积分数与活性的变化特征;同时结合光化学箱模型对深圳市O_(3)污染来源进行了量化分析。研究发现:阴雨天VOCs局地累积效应增强,O_(3)生成主要受限于光照条件;偏东气流影响下,VOCs存在老化现象,沿海长距离传输使O_(3)体积分数维持在较高水平;在持续偏北气流影响下,O_(3)体积分数的峰值组成中区域残留贡献39.7%,化学生成贡献37.6%,区域传输贡献22.7%;与受南北气流交替影响下的臭氧污染过程比较,持续偏北气流影响下臭氧来源区域传输贡献更加突出,且VOCs组分以芳香烃升高为主。深圳市O_(3)主要来源于本地化学生成与区域传输贡献,建议在加强本地间/对-二甲苯、甲苯和邻-二甲苯等活性VOCs的来源管控,同时加强与北面城市的联防联控。

In this paper,the VOCs pollution characteristics and the quantification of ozone(O_(3))pollution sources in urban areas of Shenzhen from September 21;to October 18;in 2018 were analyzed by using a photo-chemical model and the observation data of general pollutants and VOCs of Lianhuashan Ecological Monitoring Station,and the meteorological data of Zhuzilin Meteorological Base.The results showed that the local cumulative effects of VOCs increased in the cloudy and rainy day,while the production of O_(3)was limited by the solar radiation.When the air flew from the east,VOCs were found to be of aging,and O_(3)brought by long-distance transmission along the coast were generally higher.When the air flew from the north,the residual effects,chemical formation and transmission contributed 39.7%,37.6%and 22.7%to the peak value of O_(3),respectively.Comparing with the ozone pollution under the influence of alternating north and south air,the former ozone pollution was more prominently contributed by the transmission,and VOCs components were mainly increased by aromatic hydrocarbons.Local chemical formation and regional transmission were the main sources of O_(3)in Shenzhen.It was recommended to strengthen the control of local sources of active VOCs such as m/p-xylene,toluene,and o-xylene,and also strengthen the joint defense and control with the northern cities.