银川市秋冬季大气挥发性有机物污染特征、来源及其对臭氧的生成的影响

Pollution Characteristics and Sources of Atmospheric Volatile Organic Compounds in Autumn and Winter in Yinchuan and Their Effects on Ozone Formation

基于2021年和2022年的10月至12月银川市秋冬季挥发性有机物(VOCs)在线监测结果,分析银川市秋冬季VOCs的组分特征,并采用用正交矩阵因子分析(PMF)模型和耦合MCM机制光化学反应箱式模型(PBM-MCM)分别分析了秋冬季银川市臭氧(O_(3))浓度升高的VOCs的来源及臭氧生成敏感性。结果表明,2022年10—12月总挥发有机物(TVOC)平均浓度较2021年同期偏高6.49ppbv,增幅17.8%,烷烃、炔烃、卤代烃和含氧挥发性有机物(OVOCs)组分均同比上升,其中炔烃上升幅度最大,同比增长61.9%;2021年和2022年的10—12月各类源的分担率类似,其中2021年区域传输工业源和燃烧源贡献较多,占比分别为24.3%和22.0%,溶剂使用源1、溶剂使用源2、油气挥发源和机动车尾气源四类源占比相当,在12.3%-14.9%。2022年燃烧源贡献升至首位,占比为22.0%,其次为区域传输源、工业源,占比为18.4%,溶剂使用源1、溶剂使用源2、油气挥发源和机动车尾气源四类源占比相当,在13.2%-16.7%。2021年和2022年的10—12月基本位于VOCs控制区,其中2022年12月人为源对臭氧生成的敏感性最大,如达到臭氧生成潜势降低10%的目标,按比例削减VOCs和NO_(X)(3:1),排放量总削减百分比达到27%。由此可见,现阶段削减VOCs仍是银川市降低臭氧生成潜势的有效途径。

Based on the online monitoring results of volatile organic compounds(VOCs) in autumn and winter of Yinchuan from October to December 2021 and 2022,the composition characteristics of VOCs in autumn and winter of Yinchuan were analyzed.The orthogonal matrix factor analysis(PMF) model and the coupled MCM mechanism photochemical reaction box model(PBM-MCM) were used to analyze the sources and ozone generation sensitivity of VOCs with increased ozone(O_3) concentration in autumn and winter of Yinchuan.The results showed that the average concentration of total volatile organic compounds(TVOC) from October to December 2022 was 6.49 ppbv,higher than the same period in 2021,with an increase of 17.8%.The components of alkanes,alkynes,halogenated hydrocarbons,and oxygen-containing volatile organic compounds(OVOCs) all increased year-on-year,among which alkynes show the largest growth and a year-on-year increase of 61.9%;and the sharing rate of each source in October December 2021 and 2022 was similar,with regional transmission industrial sources and combustion sources contributing more in 2021,accounting for 24.3% and 22.0% respectively.The proportion of solvent application sources included:1.solvent,2.oil and gas volatilization sources,and 3.motor vehicle exhaust,all of which were equivalent,ranging from 12.3% to 14.9%.In 2022,the contribution of combustion sources has risen to the top,accounting for 22.0%,followed by regional transmission sources and industrial sources,accounting for 18.4%.The solvent application source included:1.solvent,2.oil and gas volatilization sources,and 3.motor vehicle exhaust,all of which were equivalent,accounting for 13.2%-16.7%.The period from October to December 2021 and 2022 was basically located in the VOCs control zone.Among them,in December 2022,anthropogenic sources were most sensitive to ozone generation.If the goal of reducing ozone generation potential by 10% was achieved,VOCs and NO_(X) would be reduced proportionally(3:1),and the total emission reduction percentage would reach 27%.It can be seen that reducing VOCs was still an effective way for Yinchuan to reduce the potential for ozone generation at the current stage.