广州秋季HONO污染特征及夜间来源分析  

HONO Pollution Characteristics and Nighttime Sources During Autumn in Guangzhou,China

作　　者：田智林 杨闻达 虞小芳 张曼曼 张贺伟 程丁 程鹏 王伯光 TIAN Zhi-lin1,2, YANG Wen-da1,3, YU Xiao-fang1,3, ZHANG Man-man1,3, ZHANG He-wei1,3, CHENG Ding1,3, CHENG Peng1,3 ,WANG Bo-guang1,2.(1. Institute of Mass Spectrometer and Atmospheric Environment, Jinan University, Guangzhou 510632, China; 2. Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, China; 3. Guangdong Provincial Engineering Research Center for On-line Source Apportionment System of Air Pollution, Jinan University, Guangzhou 510632, Chin)

机构地区：[1]暨南大学质谱仪器与大气环境研究所,广州510632 [2]暨南大学环境与气候研究院,广州511443 [3]广东省大气污染在线源解析系统工程技术研究中心,广州510632

出　　处：《环境科学》2018年第5期2000-2009,共10页Environmental Science

基　　金：国家自然科学基金青年科学基金项目(41405002);国家重点研发计划项目(2017YFC0210104);科技部科技支撑计划项目(2014BAC21B01)

摘　　要：大气亚硝酸(HONO)光解是对流层大气中OH自由基(·OH)的主要来源,对光化学过程具有重要作用,但其夜间化学过程的研究较为薄弱.本文利用2015年10月暨南大学大气超级站的HONO及相关参数的观测数据,针对夜间HONO的污染过程和来源进行了分析.结果表明广州秋季HONO夜间浓度平均值为4.32μg·m^(-3),是日间浓度平均值(1.67μg·m^(-3))的2.6倍;夜间HONO平均转化率CHONO为0.006 8 h-1;夜间机动车直接排放对HONO的平均贡献为15.1%,并在20:00左右出现峰值(37.8%);夜间NO和·OH反应生成HONO的净速率平均值为0.44μg·(m^3·h)^(-1);相关性分析,发现大气颗粒物对HONO的生成不重要,但相对湿度(33%<RH<78%)对HONO生成具有显著促进作用.相关计算表明沉降的NO_2与水汽在地表的非均相反应可能是夜间HONO的主要来源.Nitrous acid（ HONO） plays an important role in atmospheric photochemistry processes because its photolysis provides an efficient source of hydroxyl（ OH） radicals in the troposphere. However,few studies exist on HONO in nocturnal chemistry processes.Using the observation data of HONO and related parameters for a super site at Guangzhou Jinan University in October 2015,the pollution processes and sources of HONO during nighttime were analyzed in this study. The results showed that the average concentration of HONO was 4. 32 μg·m^（-3） during the nighttime,which was 2. 6 times its concentration of 1. 67 μg·m^（-3） in the daytime.The conversion rate of HONO,CHONO,during the nighttime was 0. 006 8 h^（-1）,and the average contribution of vehicle emissions to HONO was 15. 1%,with a peak of 37. 8% at 20： 00. The average net HONO generation rate from the reaction of NO and OH radicals during the night was 0. 44 μg·（ m^3·h）^（-1）. Correlation analysis suggested that particles could not be the major HONO source,but that relative humidity（ RH; 33%-78%） was a key factor. Relevant calculation indicated that the heterogeneous reaction of deposited NO2 on humid ground surfaces could be the main source of HONO during nighttime.

关 键 词：气态亚硝酸 污染特征 夜间来源 直接排放 气相反应 

分 类 号：X511[环境科学与工程—环境工程]