Wintertime ozone surges:The critical role of alkene ozonolysis  

作　　者：Jin Yang Yangzong Zeren Hai Guo Yu Wang Xiaopu Lyu Beining Zhou Hong Gao Dawen Yao Zhanxiang Wang Shizhen Zhao Jun Li Gan Zhang 

机构地区：[1]Air Quality Studies,Department of Civil and Environmental Engineering,Kowloon,999077,The Hong Kong Polytechnic University,Hong Kong,China [2]Research Institute for Land and Space,The Hong Kong Polytechnic University,Kowloon,999077,Hong Kong,China [3]Department of Geography&Smart Society Lab,Hong Kong Baptist University,Kowloon,999077,Hong Kong,China [4]Key Laboratory for Environmental Pollution Prediction and Control,College of Earth and Environmental Sciences,Lanzhou University,Lanzhou,Gansu,730050,China [5]Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou,511443,China

出　　处：《Environmental Science and Ecotechnology》2024年第6期304-313,共10页环境科学与生态技术（英文）

基　　金：Research Grants Council(RGC)of the Government of the Hong Kong Special Administrative Region(PolyU 152124/21 E and N_PolyU530/20);research support scheme of Research Institute for Land and Space at The Hong Kong Polytechnic University(1-CD79);Start-up Fund for RAPs under the Strategic Hiring Scheme of the Hong Kong Polytechnic University(1-BD3T).

摘　　要：Ozone(O_(3))pollution is usually linked to warm weather and strong solar radiation,making it uncommon in cold winters.However,an unusual occurrence of four high O_(3)episode days(with maximum hourly concentrations exceeding 100 ppbv and peaking at 121 ppbv)was recorded in January 2018 in Lanzhou city,China.During these episodes,the average daytime concentration of total non-methane volatile organic compounds(TVOCs)reached 153.4±19.0 ppbv,with alkenes—largely emitted from the local petrochemical industry—comprising 82.3±13.1 ppbv.Here we show a photochemical box model coupled with a Master Chemical Mechanism to elucidate the mechanisms behind this unusual wintertime O_(3)pollution.We find that the typically low temperatures(−1.7±1.3℃)and weak solar radiation(263.6±60.7 W m^(-2))of those winter episode days had a minimal effect on the reactivity of VOCs with OH radicals.Instead,the ozonolysis of alkenes generated Criegee intermediates,which rapidly decomposed into substantial ROx radicals(OH,HO_(2),and RO_(2))without sunlight.This radical production led to the oxidation of VOCs,with alkene ozonolysis ultimately contributing to 89.6±8.7%of the O_(3)formation during these episodes.This mechanism did not activate at night due to the depletion of O_(3)by the NO titration effect.Furthermore,the findings indicate that a reduction of alkenes by 28.6%or NO_(x)by 27.7%in the early afternoon could significantly mitigate wintertime O_(3)pollution.Overall,this study unravels the unique mechanism of alkene-induced winter O_(3)pollution and offers a reference for winter O_(3)reduction strategies in the petrochemical industrial regions.

关 键 词：Ozone pollution Winter ALKENES Radical chemistry PBM-MCM 

分 类 号：X703[环境科学与工程—环境工程]