摘要
臭氧已成为影响我国环境空气质量的重要污染物之一,准确解析环境臭氧及其前体物VOCs的关键源类及其贡献对于有效防控臭氧污染具有重要作用.因此,利用光化学年龄参数方法估算了青岛胶州市2021年1月1日至2月28日在线VOCs监测数据的初始浓度,矫正环境VOCs物种的光化学损耗;并利用正定矩阵因子分解(PMF)和臭氧生成潜势(OFP)模型进行了环境VOCs及其OFP来源解析研究,以期为青岛市环境臭氧污染的防控提供数据支撑.结果表明,研究期间青岛市环境ρ(TVOCs)和OFP的平均值分别为65.9μg·m^(-3)和176.7μg·m^(-3);其中丙烷浓度(12.4μg·m^(-3))和占比(18.9%)最高,而间/对-二甲苯的OFP(24.6μg·m^(-3))及占比(13.9%)最高.研究期间TVOCs的初始浓度为153.1μg·m^(-3),其光化学损耗率达到63.8%.烯烃是光化学损耗率(92.1%)最高的VOCs物种,其中异戊二烯的光化学损耗率达到98.6%,明显高于其它VOCs物种.基于初始浓度的来源解析(IC-PMF)结果来看,液化石油气(24.2%)、溶剂使用(17.8%)、天然气和石化相关企业排放(16.6%)、汽油挥发(13.2%)、燃烧和汽油车排放(12.2%)、植物排放(8.6%)及柴油车排放(7.4%)是青岛胶州市环境VOCs主要的贡献源类.相比于IC-PMF的解析结果,基于观测浓度的解析结果(OC-PMF)中植物排放贡献被低估了38.9%,天然气和石化相关企业排放的贡献低估了28.5%;其贡献的低估量明显高于其它源类.相比春节前,春节期间汽油挥发对于VOCs贡献显著增加;相比春节期间,春节后溶剂使用、燃烧和汽油车排放对于VOCs贡献增加最为明显.研究期间环境臭氧生成的主要贡献源类为溶剂使用(31.3%)、天然气和石化相关企业排放(16.1%)、植物排放(14.5%)和燃烧和汽油车排放(13.2%).春节期间不同时期臭氧生成首要贡献源类表现出明显差异.春节前溶剂使用的贡献浓度最高(71.1μg·m^(-3)),春节期间汽油挥发是最高的贡献源类(34.4μg·m^(-3)),而春节后植物排放是最高的贡献源类(39.1μg·m^(-3)).
Ozone was one of the major pollutants affecting the environmental air quality in China.The accurate apportionment of key sources and their contributions of ambient ozone and its precursor VOCs played an important role in the effective prevention and control of ozone pollution.Therefore,this study utilized the photochemical-age-based parameterization method to estimate the initial concentrations of ambient VOCs data collected from January 1 to February 28,2021 in Jiaozhou,Qingdao and corrected the photochemical losses of ambient VOC species.The positive matrix factorization(PMF)and ozone formation potential(OFP)models were used to conduct source apportionment of ambient VOCs and their OFPs so as to provide data support for the prevention and control of ozone pollution in Qingdao.The results showed that the average values of ambientρ(TVOCs)and OFP in Qingdao during the study period were 65.9μg·m^(-3) and 176.7μg·m^(-3),respectively.Propane had the highest concentration(12.4μg·m^(-3))and percentage(18.9%),whereas m/p-xylene had the highest OFP(24.6μg·m^(-3))and percentage(13.9%).The mean initial concentration of TVOCs during the study was 153.1μg·m^(-3),and its photochemical loss rate reached 63.8%.Alkenes were the VOC species with the highest photochemical loss rate(92.1%),and the photochemical loss rate of isoprene reached 98.6%,which was substantially higher than that of other VOC species.According to the source apportionment results of initial concentrations(IC-PMF),liquefied petroleum gas(24.2%),solvent use(17.8%),natural gas and petrochemical-related enterprises(16.6%),gasoline volatilization(13.2%),combustion and gasoline vehicle emissions(12.2%),biogenic emissions(8.6%),and diesel vehicle emissions(7.4%)were the main contributing sources of the ambient VOCs in Jiaozhou.Compared with the apportioned results of IC-PMF,the contribution of biogenic emissions was underestimated by 38.9%in the apportioned results based on observed concentrations(OC-PMF),and the contribution of natural gas and petrochemical-related enterprises was underestimated by 28.5%,and the underestimations of their contributions were substantially higher than those of other sources.Compared with that before the Spring Festival,the contribution of gasoline volatilization to ambient VOCs increased markedly during the Spring Festival,whereas the contributions of solvent use,combustion,and gasoline vehicle emissions to ambient VOCs increased most significantly after the Spring Festival.The main contributing sources of ambient ozone during the study period were solvent use(31.3%),natural gas and petrochemical-related enterprises(16.1%),biogenic emissions(14.5%),and combustion and gasoline vehicle emissions(13.2%).The primary contributors of ambient ozone in different Spring Festival periods showed substantial differences.Before the Spring Festival,solvent use had the highest contribution(71.1μg·m^(-3)),and gasoline volatilization was the highest contributor during the Spring Festival(34.4μg·m^(-3)),whereas biogenic emissions after the Spring Festival were the highest contributor(39.1μg·m^(-3)).
作者
孔翠丽
吴雨彤
顾瑶
宋江邦
孟赫
石来元
刘保双
KONG Cui-li;WU Yu-tong;GU Yao;SONG Jiang-bang;MENG He;SHI Lai-yuan;LIU Bao-shuang(Jiaozhou Branch of Qingdao Ecology and Environment Bureau,Qingdao 266300,China;State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control,College of Environmental Science and Engineering,Nankai University,Tianjin 300350,China;Qingdao Eco-environment Monitoring Center of Shandong Province,Qingdao 266003,China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2023年第12期6551-6563,共13页
Environmental Science
基金
大气重污染成因与治理攻关项目(DQGG2021301)
国家自然科学基金项目(42177085)。
