摘要
基于大气综合观测站的气态污染物(HCHO、O_(3)、PAN、CO、NOx、异戊二烯)及气象要素(温度、湿度、风速、风向)等在线观测数据,研究沿海城市厦门秋季大气HCHO的时间变化特征及其关键影响因子,利用多元线性回归分析方法定量识别HCHO的主要来源,并估算HCHO对·OH生成的贡献.结果表明:HCHO平均浓度为(3.15±1.40)×10^(-9),范围为(0.55~7.96)×10^(-9),呈现明显“单峰”日变化特征,峰值出现在13:00左右.HCHO与O_(3)、PAN显著正相关;温度、湿度和UV是影响HCHO浓度的主要气象因素,强辐射、高温、低湿、低风速和西南风的条件促进了厦门大气HCHO的二次生成.HCHO小时光解量(PHCHO)范围为(0.01~3.02)×10^(-9)/h,平均PHCHO为0.61×10^(-9)/h,同时,大气HCHO光解成稳定分子H2和CO的速率是光解成自由基H·和HCO·速率的1.1~1.6倍.观测期间大气HCHO来源主要包括二次生成(39.2%)、一次排放(26.6%)和背景源(34.2%);白天HONO光解、O_(3)光解和HCHO光解的平均·OH生成率分别为1.86×10^(-9)/h、1.11×10^(-9)/h和0.70×10^(-9)/h,P(OH_HCHO)占总·OH生成率的10%~21%.
The temporal variations and key influencing factors of atmospheric formaldehyde(HCHO)in autumn in the southeastern coastal city of Xiamen were investigated using online observation data of gaseous pollutants(HCHO,O_(3),peroxyacetyl nitrate(PAN),CO,NOx,isoprene)and the meteorological parameters(temperature,humidity,wind speed,wind direction)at an atmospheric environment supersite.The major sources of HCHO were identified quantitatively using the multilinear regression analysis method,and the contribution of HCHO to the formation of hydroxyl radical(·OH)was also estimated.It showed that the diurnal variation of HCHO displayed an obvious single-peak pattern,with the peak value appearing at around 13:00;and the concentrations of HCHO varied from 0.55×10^(-9)to 7.96×10^(-9)with an average concentration of(3.15±1.40)×10^(-9).Significant positive correlations between O_(3),PAN,and HCHO were observed.Temperature,humidity,and UV were the main meteorological factors affecting HCHO levels.Intense solar radiation,high temperature,low humidity,low wind speed,and southwest wind conditions favor the secondary formation of HCHO in Xiamen.The photolysis rate of HCHO(PHCHO)ranged from 0.01×10^(-9)/h to 3.02×10^(-9)/h,with a mean value PHCHO of 0.61×10^(-9)/h.The rate of HCHO photolysis to produce stable molecules of H2 and CO was 1.1~1.6 times that of H·and HCO·free radicals.The primary sources of atmospheric HCHO in the autumn of Xiamen included secondary formations(39.2%),direct emissions(26.6%),and regional background(34.2%).During the daytime in autumn,the average·OH formation rates from the photolysis of HONO,O_(3),and HCHO were 1.86×10^(-9)/h,1.11×10^(-9)/h,and 0.70×10^(-9)/h,respectively.And the production rate of OH caused by HCHO photolysis(P(OH_HCHO))accounted for 10%~21%of the total·OH formation rate.
作者
林宜玲
洪有为
纪晓婷
许可
邵智乾
于瑞莲
陈进生
LIN Yi-ling;HONG You-wei;JI Xiao-ting;XU Ke;SHAO Zhi-qian;YU Rui-lian;CHEN Jin-sheng(College of Chemical Engineering,Huaqiao University,Xiamen 361021,China;Center for Excellence in Regional Atmospheric Environment,Institute of Urban Environment,Chinese Academy of Sciences,Xiamen 361021,China;Key Lab of Urban Environment and Health,Institute of Urban Environment,Chinese Academy of Sciences,Xiamen 361021,China;Fujian Key Laboratory of Atmospheric Ozone Pollution Prevention,Institute of Urban Environment,Chinese Academy of Sciences,Xiamen 361021,China;School of Life Sciences,Hebei University,Baoding 071000,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2023年第1期52-60,共9页
China Environmental Science
基金
国家自然科学基金资助项目(42277091)
福建省对外合作项目(2020I0038)
海洋大气化学与全球变化重点实验室开放基金资助项目(GCMAC2020)。
关键词
甲醛
污染特征
来源
大气氧化性
沿海城市
formaldehyde
pollution characteristics
source
atmospheric oxidation capacity
coastal city
作者简介
林宜玲(1998-),女,福建厦门人,硕士研究生,主要研究方向为大气光化学污染研究;责任作者:洪有为,副研究员,ywhong@iue.ac.cn;责任作者:于瑞莲,教授,ruiliany@hqu.edu.cn。
