深圳市工业区VOCs污染特征与臭氧生成敏感性

于2020年9~10月在深圳北部典型工业区开展在线观测以分析该地VOCs污染状况,并使用基于观测的模型(OBM)研究臭氧生成敏感性.观测期间VOCs的总浓度为48.5×10^-9,浓度水平上烷烃>含氧有机物(OVOCs)>卤代烃>芳香烃>烯烃>乙炔>乙腈.臭氧生成潜势(OFP)为320μg/m³,其中芳香烃、OVOCs以及烷烃贡献最大,这3类物种OFP贡献总和超过90%.乙烯与苯呈现“两峰一谷”的日变化特征,主要受到机动车排放的贡献.相对增量反应性(RIR)分析表明,削减人为源VOCs对控制当地臭氧生成最为有效,当中又应优先控制芳香烃;经典动力学曲线(EKMA)分析表明该片区臭氧生成处于过渡区,在开展VOCs区域联防联控的同时,需要在当地进行有力的NOx控制以强化该地区臭氧污染长期管控.

The characteristics of VOCs and ozone formation sensitivity in a typical industrial area in Shenzhen

VOCs were sampled online in a typical industrial area in north of Shenzhen from September to October 2020 to analyze the VOCs polluted and used the Observation-Based-Model (OBM) to study the O₃ formation sensitivity. During the sampling, the average mixing ratio of TVOCs was about 48.5×10^-9, and alkane was the most abundant species, followed by oxygenated volatile organic compounds (OVOCs), halohydrocarbon, aromatic, alkene, acetylene and acetonitrile. The average ozone formation potential (OFP) of TVOCs was 320μg/m³, among which aromatic, OVOCs and alkane contributed most, and OFP contributed by these three categories exceeded 90%. The diurnal variation of ethene and benzene shown “two peaks and one valley” pattern, mainly contributed by vehicle exhaust. The result of relative incremental reactivity (RIR) analysis indicated that reducing anthropogenic VOCs was most effective method for local O₃ formation, and aromatics should be controlled first; empirical kinetics modeling approach curve (EKMA) revealed that the local O₃ formation was in the transition area. While carrying out VOCs regional joint control, it is also necessary to carry out strong local NOx control to strengthen the long-term controlling of O₃ in this area.