摘要
近年来近地面臭氧问题日益凸显,成为影响空气质量持续改善的瓶颈.本研究基于2017年8—9月在湖州市城区开展的为期1个月的臭氧及其前体物挥发性有机物(VOCs)和氮氧化物(NOx)在线观测数据,分析了臭氧及其前体物污染特征,利用正矩阵因子分析(PMF)解析了VOCs来源,并采用基于观测的模型(OBM)对臭氧生成机制进行研究.研究结果表明:1)观测期间湖州市VOCs平均体积分数为(24.78±9.10)×10^-9,其中占比最高的组成为烷烃、含氧VOCs(OVOCs)和卤代烃;2)在臭氧非超标时段,湖州市臭氧生成处于VOCs控制区,而在臭氧重污染期间湖州市处于以VOCs控制为主的过渡区;3)在臭氧超标时段,对臭氧生成潜势(OFP)贡献最大的是芳香烃(39.6%),其次是烯烃(21.5%)和OVOCs(19.4%),排名前三的关键组分为甲苯、乙烯和间/对二甲苯;4)源解析结果显示观测期间湖州市VOCs的主要来源是溶剂使用(27.0%)、交通排放(22.7%)、背景+传输(19.3%)、工业排放(16.9%)、汽油挥发(7.7%)和植物排放(6.4%),重污染过程期间对OFP贡献最大的两类源是交通排放源和溶剂使用源,贡献百分比分别为35.1%和30.5%.因此,对交通排放和溶剂使用方面进行控制管理对湖州市大气臭氧污染防控有重要意义.
Surface ozone pollution has become a bottleneck affecting the continuous improvement of air quality in recent years.Based on online observation data of ozone and its precursors including volatile organic compounds(VOCs)and nitrogen oxides(NOx)in Huzhou during August 23rd to September 23rd,2017,the pollution characteristics of ozone and its precursors were analyzed.Furthermore,source apportionment of VOCs and the formation mechanism of ozone were investigated using positive matrix factorization(PMF)and observation based model(OBM),respectively.The results showed that average volume fraction of VOCs in Huzhou was(24.78±9.10)×10^-9 during the observation period.Alkanes,oxygenated VOCs(OVOCs),and halogenated hydrocarbons accounted for highest proportion to total VOCs.During the period when ozone concentration did not exceed air quality standard,ozone formation was in VOCs-limited regime,while during ozone pollution days,O3 formation was in transitional regime but still limited by VOCs.During O3 pollution days,aromatic hydrocarbons,olefins,and OVOCs were the three largest contributors to ozone formation potential(OFP),with relative contributions of 39.6%,21.5%,and 19.4%,respectively.The top three key components for OFP were toluene,ethylene,and m,p-xylene.PMF source apportionment results showed that the VOCs in Huzhou during the observation period were from solvent use(27.0%),traffic emission(22.7%),background and transport(19.3%),industrial emission(16.9%),gasoline volatilization(7.7%),and biogenic emission(6.4%).During O3 pollution episodes,traffic emission and solvent use were the two largest contributors to OFP,with relative contributions of 35.1%and 30.5%,respectively.Therefore,reduction in traffic emissions and solvent use is an effective way to control ozone pollution in Huzhou.
作者
常艳春
魏莉
杨晓红
费勇
沈学勇
陈江
张海燕
缪丽娜
CHANG Yanchun;WEI Li;YANG Xiaohong;FEI Yong;SHEN Xueyong;CHEN Jiang;ZHANG Haiyan;MIAO Lina(Huzhou Environmental Protection Monitoring Center Station,Huzhou 313000;Nanjing Intelligent Environmental Sci-Tech Company Limited,Nanjing 211800)
出处
《南京信息工程大学学报(自然科学版)》
CAS
2020年第6期739-748,共10页
Journal of Nanjing University of Information Science & Technology(Natural Science Edition)
关键词
臭氧
挥发性有机物
敏感性分析
臭氧生成潜势
源解析
ozone
volatile organic compounds
sensitivity analysis
ozone formation potential
source apportionment