上海城区大气OH自由基反应活性的连续测量及其组成解析  

Continuous measurement and constituents analysis of OH reactivity in urban area of Shanghai

作　　者：杨舒春 周文鑫 黄聪艳 吴宇航 景盛翱 周俊 袁斌 楼晟荣 YANG Shuchun;ZHOU Wenxin;HUANG Congyan;WU Yuhang;JING Shengao;ZHOU Jun;YUANBin;LOU Shengrong(Institute for Environmental and Climate Research,Jinan University,Guangzhou 511443;Guangdong-Hongkong-Macao Joint Laboratory of Collaborative Innovation for Environmental Quality,Guangzhou 511443;State Environmental Protection Key Laboratory of Formation and Prevention of the Urban Air Pollution Complex,Shanghai Academy of Environmental Sciences,Shanghai 200233;School of Energy and Power Engineering,University of Shanghai for Science and Technology,Shanghai 200093)

机构地区：[1]暨南大学环境与气候研究院,广州511443 [2]粤港澳环境质量协同创新联合实验室,广州511443 [3]上海环境科学研究院,国家环境保护城市大气复合污染成因与防治重点实验室,上海200233 [4]上海理工大学能源与动力工程学院,上海200093

出　　处：《环境科学学报》2024年第9期103-114,共12页Acta Scientiae Circumstantiae

基　　金：国家重点研发计划(No.2023YFC3706200);国家自然科学基金(No.22176129)。

摘　　要：OH自由基反应活性(k_(OH))是判断大气氧化性的重要指标之一.本研究采用基于激光光解-激光诱导荧光技术(LP-LIF)的k_(OH)测量系统,于2023年春夏季在上海城区进行了k_(OH)测量,并同步测量无机痕量气体、甲烷以及挥发性有机物(VOCs)以探究k_(OH)变化特征及主要组成成分,并分析活性缺失的可能来源.研究结果表明,观测期间OH自由基反应活性平均测量值为13.1 s^(-1),日变化特征显著,平均存在27%的活性缺失.无机化合物和一次排放的VOCs对k_(OH)的贡献较大,其次是以甲醛和乙醛作为优势物种的含氧挥发性有机物(OVOCs),贡献占比最高可达到17.9%.通过结合光化学盒子模型,发现未测量的OVOCs物种是造成活性缺失的主要物种,其中乙二醛和甲基乙二醛占据k_(OH)模拟值的11.5%~12.5%.同时利用多元线性回归模型对4月和6月的活性缺失来源进行探究后,发现工业排放及溶剂使用对活性缺失的影响显著,影响占比分别为50.62%和29.1%.OH reactivity(k_(OH))is one of the key indicators of atmospheric oxidation capacity.A k_(OH) measurement system based on laser flash photolysis-laser induced fluorescence(LP-LIF)technology was used to measure k_(OH) in the urban area of Shanghai during the spring and summer of 2023.Along with measurements of inorganic trace gases,methane,and volatile organic compounds(VOCs),this study focused on the characteristics of k_(OH) variation,explored its main constituents and analyzed the possible sources of the missing OH reactivity.The results showed that the mean measured OH reactivity was 13.1 s-1 with a significant daily variation while the averaged missing OH reactivity was about 27%during the observation.Inorganic compounds and primary emission VOCs were the main contributors to k_(OH),followed by oxygenated volatile organic compounds(OVOCs)that mainly were formaldehyde and acetaldehyde,contributing up to 17.9%of k_(OH).By using the photochemical box model,the unmeasured OVOCs species were modeled,and the result showed glyoxal and methylglyoxal could contribute 11.5%~12.5%to all modelled k_(OH).With the application of multiple linear regression model,the possible sources of missing OH reactivity in April and June were explored,revealing the significance of industrial emissions and solvent usage,accounting for 50.62%and 29.1%of missing k_(OH),respectively.

关 键 词：OH自由基反应活性 激光闪光光解-激光诱导荧光技术 活性缺失 挥发性有机物 大气氧化性 

分 类 号：X51[环境科学与工程—环境工程]