莆田市O3污染来源解析模拟研究

福建省莆田市作为典型的海滨城市，自2015年以来以O₃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O₃污染，以2016年莆田市O₃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O₃来源追踪方法分析了莆田市近地面O₃生成控制区，以及O₃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（O₃）的贡献率仅为21.0%，福建省福州市和泉州市对莆田市ρ（O₃）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O₃的外来输送不仅发生在ρ（O₃）较高的时段，在ρ（O₃）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（O₃）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（O₃）峰值下降约5 μg/m3.研究显示，莆田市NO_x与VOCs主要来自本地排放，O₃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O₃污染的有效方法. 

Analysis and Source Apportionment of Ozone Pollution in Putian City

In order to reduce the O₃ pollution in Putian City, it is necessary to develop scientific and effective emission reduction measures. The ground-level ozone (O₃) pollution problem in Putian City in 2016 was studied via observation data analysis, sensitivity analysis and source apportionment modeling. The O₃ sensitive zone, regional and sectorial emission source contributions to the ambient NO_x, VOC and O₃ 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% O₃ 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% O₃ in Putian City, and the adjacent Zhejiang Province contributes approximately 11.6%. The regional-wide O₃ transport occurs not only in the high O₃ episode, but also in the low O₃ concentration period. (3) Industrial sources contribute the most, about 57%, to the locally formed O₃ 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 O₃ concentrations by about 5 μg/m3 at the national monitoring sites. The research shows that NO_x and VOCs mainly come from the local emission contribution in Putian City, and O₃ is affected by external transmission. The largest emission is the local industrial source. O₃ pollution can be alleviated by reducing certain emissions of NO_x and VOCs.