莆田市O3污染来源解析模拟研究

Analysis and Source Apportionment of Ozone Pollution in Putian City

福建省莆田市作为典型的海滨城市,自2015年以来以O 3为首要污染物的天数逐年增加.为了制定科学有效的减排措施,减轻莆田市的O 3污染,以2016年莆田市O 3污染高发的7—9月为研究时段,通过观测数据分析、空气质量模型敏感性分析和O 3来源追踪方法分析了莆田市近地面O 3生成控制区,以及O 3及其生成前体物NO x 与VOCs的区域和行业来源.结果表明:①莆田市西部地区为NO x 控制区,而东部沿海地区则为VOCs控制区.②莆田市ρ(NO x)与ρ(VOCs)主要来自本地排放贡献,二者本地排放的贡献率分别为69.4%与64.2%,而本地排放对莆田市ρ(O 3)的贡献率仅为21.0%,福建省福州市和泉州市对莆田市ρ(O 3)的贡献率之和为37.6%,外来输送贡献率较大的为浙江省,其贡献率为11.6%.莆田市O 3的外来输送不仅发生在ρ(O 3)较高的时段,在ρ(O 3)较低的时段也占了很大的比例.③莆田市工业源对本地排放ρ(O 3)贡献率最大,达57%,其次是机动车源.④通过敏感性时间序列分析得出,同时削减10%的NO x 和VOCs排放,能使莆田市国控点位平均ρ(O 3)峰值下降约5 μg/m^3.研究显示,莆田市NO x 与VOCs主要来自本地排放,O 3受外来输送影响较大,推进本地工业NO x 和VOCs污染的治理与加强机动车尾气的污染控制是减轻本地O 3污染的有效方法.

In order to reduce the O 3 pollution in Putian City,it is necessary to develop scientific and effective emission reduction measures.The ground-level ozone (O 3) pollution problem in Putian City in 2016 was studied via observation data analysis,sensitivity analysis and source apportionment modeling.The O 3 sensitive zone,regional and sectorial emission source contributions to the ambient NO x ,VOC and O 3 in Putian City were determined and analyzed.The results show that:(1) Controlling NO x emissions is beneficial for ozone reduction in the western mountain area,while it appears VOC sensitive in the eastern coast area of Putian City.(2) About 69.4% NO x and 64.2% of VOCs in Putian City are mainly caused by local emissions.However,only 21.0% O 3 are formed from locally emitted NO x and VOCs.Source apportionment modeling indicates that the emissions from Fuzhou City and Quanzhou City in Fujian Province contribute almost 37.6% O 3 in Putian City,and the adjacent Zhejiang Province contributes approximately 11.6%.The regional-wide O 3 transport occurs not only in the high O 3 episode,but also in the low O 3 concentration period.(3) Industrial sources contribute the most,about 57%,to the locally formed O 3 concentrations in Putian City,followed by mobile sources.(4) Based on time the series sensitivity analysis results,reducing local NO x and VOCs emissions simultaneously by 10% may achieve the averaged reduction of the peak O 3 concentrations by about 5 μg/m^3 at the national monitoring sites.The research shows that NO x and VOCs mainly come from the local emission contribution in Putian City,and O 3 is affected by external transmission.The largest emission is the local industrial source.O 3 pollution can be alleviated by reducing certain emissions of NO x and VOCs.