武汉夏季大气羰基化合物的污染特征及光化学反应性  

Pollution characteristics and photochemical reaction of atmospheric carbonyl compounds during summer in Wuhan

作　　者：裴小芬 陶卉婷 胡柯 成海容[1] PEI Xiaofen;TAO Huiting;HU Ke;CHENG Hairong(School of Resource and Environment Science,Wuhan University,Wuhan 430072;Wuhan Environment Monitoring Center,Wuhan 430015)

机构地区：[1]武汉大学资源与环境科学学院,武汉430072 [2]武汉市生态环境监控中心,武汉430015

出　　处：《环境科学学报》2025年第3期33-41,共9页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金(No.42277093);湖北省杰出青年项目(No.2023AFA057);中央高校基本科研业务费专项资金(No.2042024kf0013)。

摘　　要：在武汉市夏季典型臭氧污染时期(2021年7月31日—8月8日)开展大气羰基化合物的离线观测,分析不同臭氧浓度水平下羰基化合物的化学特征,并利用基于观测的光化学反应模型(PBM-MCM)识别羰基化合物对HO_(2)自由基和O_(3)生成的贡献.结果表明,武汉城区夏季高臭氧日大气羰基化合物总浓度为(33.63±3.76)μg·m^(-3),约为非高臭氧日的1.35倍.甲醛和乙醛是最主要的羰基化合物,两者均呈现“单峰型”日变化规律.武汉城区夏季高臭氧日与非高臭氧日乙醛和丙醛特征比值(C_(2)/C_(3))分别为3.78和4.78,表明高臭氧日受人为源影响较大.PBM-MCM模拟结果显示,在高臭氧日和非高臭氧日,甲醛的光化学反应的HO_(2)生成速率分别为2.62×10^(-9)h^(-1)和2.17×10^(-9)h^(-1),贡献率分别为27.32%和28.00%,说明甲醛对HO_(2)生成具有重要作用;且未输入羰基化合物观测数据模拟时O_(3)的净生成速率相比输入羰基化合物观测数据模拟时下降超过50%,表明羰基化合物对O_(3)的生成贡献大.甲醛和乙醛在高臭氧日和非高臭氧日均对臭氧生成的贡献最大,且明显高于其他非甲烷碳氢化合物.研究结果有助于提高对武汉市大气羰基化合物光化学反应性的认识,为武汉市政府科学防控臭氧污染提供科学依据.During a typical ozone pollution period(July 31st to August 8th,2021),we conducted a measurement on atmospheric carbonyl compounds,at un urban site in Wuhan,to analyze their chemical characteristics and relationships with ozone.The photochemical reactions of carbonyls were simulated with an observation-based photochemical reaction box model(PBM-MCM)to identify the contribution of carbonyls to HO_(2)radical and O_(3)formation.The total concentration of carbonyls on high ozone days was(33.63±3.76)μg·m^(-3),which was approximately 1.35 times higher than that on non-high ozone days.Among these,formaldehyde and acetaldehyde were the most abundant,both exhibiting a"single-peak"at noon.The ratios of acetaldehyde to propionaldehyde(C_(2)/C_(3))were 3.78 and 4.78 on high ozone days and non-high ozone days,respectively,indicating that human activities have a greater impact on high ozone days.The simulation based on PBM-MCM shows that on high ozone days and non-high ozone days,the generation rates of HO_(2)contributed by HCHO were 2.62×10^(-9)h^(-1)and 2.17×10^(-9)h^(-1),accounting for 27.32%and 28.00%to total HO_(2)generation,proving the importance of HCHO.When removing aldehyde data in the simulation,the net generation rate of O_(3)decreases by over 50%,suggesting that carbonyl compounds play a significant role.The contribution of formaldehyde and acetaldehyde to ozone were the highest on both high ozone days and non-high ozone days,and are significantly higher than other non-methane hydrocarbons.This study helps to enhance our understanding of atmospheric carbonyls and its photochemical reactivity,providing valuable datasets for local authorities to formulate strategies against ozone.

关 键 词：羰基化合物 污染特征 光化学反应性 PBM-MCM模型 武汉 

分 类 号：X831[环境科学与工程—环境工程] X515