海南区域背景点光化学污染特征及VOCs来源解析  

Characteristics of photochemical pollution and sources analysis of atmospheric volatile organic compounds in the regional background station of Hainan

作　　者：林尤静 颜为军 徐文帅 杜传东 王伯光 龚道程 李勤勤 盛慧 孟鑫鑫 LIN You-jing;YAN Wei-jun;XU Wen-shuai;DU Chuan-dong;WANG Bo-guang;GONG Dao-cheng;LI Qin-qin;SHENG Hui;MENG Xin-xin(Hainan Ecological Environmental Monitoring Center,Haikou 571126,China;Institute for Environmental and Climate Research,Jinan University,Guangzhou 511443,China)

机构地区：[1]海南省生态环境监测中心,海南海口571126 [2]暨南大学环境与气候研究院,广东广州511443

出　　处：《中国环境科学》2024年第5期2418-2430,共13页China Environmental Science

基　　金：海南省重大科技计划项目(ZDKJ202007);海南省院士创新平台科研专项(YSPTZX202205);海南省自然科学基金青年基金资助项目(423QN315)。

摘　　要：海南区域背景点位于海南省东北部,是热带地区大气传输通道上的重要站点.于2021年8月~12月在海南区域背景点开展光化学污染物(O_(3)、PAN)及其前体物VOCs的在线观测,分析了光化学污染变化特征及规律、VOCs的组成特征、臭氧生成潜势(OFP)及化学活性(L^(·OH)),并利用PSCF和PMF方法进行VOCs来源解析.结果表明,海南区域背景站环境空气污染物浓度水平较低.当主导风向转偏北风后,各项污染物浓度升高.O_(3)在气象条件影响下白天生成夜间积累,形成光化学污染.观测期间光化学反应前体物VOCs平均浓度(体积分数)为(7.21×10^(-9)±4.60×10^(-9)),各类VOCs浓度从大到小排序为烷烃>OVOC>芳香烃>烯烃>炔烃.污染期各项浓度显著高于清洁期.VOCs活性分析结果表明OVOC和烯烃主要参与光化学反应.污染期前体物、PAN和O_(3)的潜在来源高值区主要分布在珠三角至福建东南部发达的沿海地区.根据PMF源解析模型分析结果海南区域站受到人为源显著影响,机动车尾气(37.8%~46.2%)是海南O_(3)污染的重要贡献来源.The regional background site in Hainan Province is located in the northeastern part of Hainan Province and serves as an important site along the atmospheric transport pathway in tropical regions in China.This study conducted online observations of photochemical pollutants(O_(3),PAN)and their precursors VOCs from August to December 2021 at the regional background site.The study analyzed the characteristics and trends of photochemical pollution,the composition of VOCs,ozone formation potential(OFP),and chemical reactivity(L^(·OH)),and utilized PSCF and PMF methods to investigate the sources of VOCs.The results indicated that the concentration levels of ambient air pollutants at the regional background site in Hainan were relatively low.However,when northerly winds prevailed as the dominant wind direction,concentrations of various pollutants increased.O_(3) was generated during the day and accumulated at night under the influence of meteorological conditions,leading to photochemical pollution.The average concentration(volume fraction)of photochemical precursor VOCs during the observation period was 7.21×10^(-9)±4.60×10^(-9),with concentrations of various types of VOCs ranked from highest to lowest as alkanes>OVOC>aromatics>alkenes>alkynes.Pollutant concentrations were significantly higher during pollution periods compared to clean periods.Analysis of VOCs reactivity revealed that OVOC and alkenes were the main contributors to photochemical reactions.High-value areas of potential sources of precursors,PAN,and O_(3) during pollution periods were mainly distributed in the developed coastal areas from the Pearl River Delta to the southeast of Fujian.According to the results obtained using PMF source analysis model,this regional background site was significantly influenced by anthropogenic sources,with vehicular exhaust emissions(37.8%to 46.2%)being an important contributor to O_(3) pollution in Hainan.

关 键 词：区域背景 光化学污染 VOCS 反应活性 来源解析 

分 类 号：X511[环境科学与工程—环境工程]