摘要
2020年9月对长三角区域唯一一个连续9天出现臭氧污染的城市六安市的臭氧污染过程进行了深入分析并于2020年秋季在六安市城市监测站点进行为期41天的连续在线VOCs监测,探究了臭氧前体物挥发性有机物(VOCs)的浓度水平和组成变化特征,根据臭氧生成潜势(OFP)得到了监测站点的关键臭氧生成前体物,利用受体模型(PMF)解析了VOCs的来源,据此提出了六安市臭氧和VOCs污染防治对策。结果表明,六安市的臭氧污染是气象因素和人为因素共同主导,受台风外围的下沉气流及高空臭氧的垂直输送影响,加上水平扩散较差,导致出现连续的臭氧污染。监测站点VOCs平均浓度水平为30.9 ppb,占比较高的VOCs类别为烷烃。OFP值与浓度值均大于该站点90分位数的组分为间/对二甲苯、甲苯,这2种组分同时兼具较高的臭氧贡献潜势与管控减排潜力;监测大楼站点OFP值排名前十的组分中,芳香烃占5种,烯烃占4种,OVOCs占1种,说明当地工业排放和溶剂使用对臭氧生成起了主要的促进作用。运用PMF受体模型确定了燃烧源、溶剂使用源、工业排放源、油品挥发源、植物源、机动车尾气排放源,六安市的O3生成起到主导作用的是机动车尾气源和工业排放源,建议作为优控源。
In September 2020, the ozone pollution process of Lu’an City, the only city in the Yangtze River Delta with ozone pollution for 9 consecutive days, was analyzed in depth. In the autumn of 2020, the 41-day continuous online VOCs monitoring was carried out at the urban monitoring station of Lu’an City, exploring the concentration level and composition change characteristics of volatile organic compounds (VOCs) as ozone precursors. According to the ozone generation potential (OFP), the key ozone precursors at the monitoring station were obtained, the source of VOCs was analyzed by using the receptor model (PMF), and the prevention and control measures of ozone and VOCs pollution in Lu’an City were put forward accordingly. The results show that the ozone pollution in Lu’an City is jointly dominated by meteorological factors and human factors. Influenced by the downdraft around the typhoon and the vertical transport of ozone in the upper air, coupled with poor horizontal diffusion, continuous ozone pollution occurs. The average concentration level of VOCs at the monitoring station is 30.9 ppb, and the VOCs with high proportion are alkanes. The components whose OFP value and concentration value are greater than the 90th percentile of the site are m-xylene/p-xylene and toluene, both of which have high ozone contribution potential and control and emission reduction potential;among the top ten components with OFP values at the monitoring building site, 5 are aromatic hydrocarbons, 4 are olefins, and 1 is OVOCs, indicating that local industrial emissions and solvent use play a major role in promoting ozone generation. The PMF receptor model is used to determine the combustion source, solvent use source, industrial emission source, oil volatile source, plant source, and vehicle exhaust emission source. The vehicle exhaust gas source and industrial emission source play a leading role in the generation of O3 in Lu’an City, and it is recommended to be the optimal control source.
出处
《自然科学》
2023年第1期81-95,共15页
Open Journal of Nature Science
