珠海市2021-2023年挥发性有机物污染特征及来源解析
- Characteristics and source analysis of VOCs pollution in Zhuhai from 2021 to 2023
- 摘要：近年来珠海市O3对空气质量的影响已超过细颗粒物（PM2.5），臭氧(O3)污染问题突出。为了深入认识珠海市O3前体物挥发性有机物（VOCs）组成特征及来源，重点利用基于观测的模型（OBM）、比值分析和PMF模型对比研究了珠海市2021年-2023年VOCs来源和贡献。研究表明,①珠海市中心城区VOCs呈现烷烃＞芳香烃＞烯烃＞炔烃的特征，与东莞、江门、佛山等珠三角城市一致，但总VOCs浓度显著低于其他城市。②间/对-二甲苯、甲苯、邻二甲苯、乙烯、丙烯、正丁烷、异丁烷、异戊烷等8个物种均出现各年度臭氧生成潜势（OFP）前十中，是对O3生成贡献最大的物种。珠海市中心城区O3生成处于VOCs控制区，减少 VOCs浓度有利于降低O3，在一定程度上降低NOx浓度可促进O3生成，各类二甲苯和CO对O3生成最敏感。③溶剂使用源对珠海市OFP贡献最大，甲苯、间/对-二甲苯、邻二甲苯是主要贡献物种，需重点关注。
- Abstract：In recent years, ozone (O?) has surpassed fine particulate matter (PM?.?) as the primary factor influencing the Air Quality Index in Zhuhai, underscoring the growing severity of O? pollution in the region. To enhance understanding of the characteristic and sources of volatile organic compounds (VOCs), which serve as key precursors to O? formation, this study utilized observation-based modeling (OBM), ratio analysis, and Positive Matrix Factorization (PMF) to analyze VOC sources and their contributions in Zhuhai from 2021 to 2023. The findings provide several key insights. First, in Zhuhai’s central urban area, alkanes were the most prevalent VOC species, followed by aromatics, alkenes, and alkynes in descending order of abundance, consistent with patterns observed in other Pearl River Delta cities such as Dongguan, Jiangmen, and Foshan. However, the total VOC concentration in Zhuhai was significantly lower than in these neighboring urban centers. Second, the compounds m/p-xylene, toluene, o-xylene, ethylene, propylene, n-butane, isobutane and isopentane were consistently identified among the top ten contributors to ozone formation potential (OFP) each year, which were dominant contributors to the O? production. Ozone formation in Zhuhai’s central urban area is within the VOC limited regime, with O3 formation being the most sensitive to xylene and CO. Reducing VOC concentrations is beneficial for lowering O3 levels, while decreasing NOx concentrations to some extent can promote O3 formation. Third, solvent usage emerged as the most significant source of OFP, with toluene, o-xylene, p-xylene, and m-xylene as the primary species of concern.
