摘要
有机酸是大气中含量丰富的有机化合物,对二次有机气溶胶的产生、云凝结核的形成和大气降水pH有重要影响.本研究利用GC-MS和离子色谱技术分析了典型城市北京市和典型酿酒工业集群区贵州省茅台镇环境空气小分子有机酸浓度和组成特征,并探讨不同天气条件下有机酸浓度变化规律.结果表明:茅台镇大气中总有机酸平均浓度为(46.47±18.81)μg·m^(-3),北京为(22.98±14.27)μg·m^(-3),有机酸对茅台地区大气总酸的贡献较大.乙酸是两地环境空气中含量最为丰富的小分子有机酸,其中茅台镇乙酸浓度为(38.33±16.65)μg·m^(-3),北京市乙酸浓度为(11.77±8.45)μg·m^(-3).茅台镇环境空气中有机酸浓度通常在上午的10:00-13:00或下午16:00-19:00时达到最高点,而北京地区小分子有机酸浓度日变化峰值出现在16:00-19:00.在不同的天气条件下,北京的环境空气中有机酸的浓度会随着PM_(2.5)、NO_(2)和CO的浓度以及相对湿度的上升而增加.而在茅台地区,小分子有机酸的浓度会随着NO2浓度的增大而增大,随风速的增大则会减小.由于地形因素的差异,北京市有机酸主要受到区域气象因素和汽车尾气排放的双重影响,而茅台镇受本地排放源的影响更为显著.此外,通过对比中国典型城市北京、深圳和上海大气中的甲酸和乙酸浓度的历史变化,发现有机酸浓度正在升高,未来需深入探究大气中有机酸变化特征,强化有机酸生态环境风险防控.
Organic acids are abundant organic compounds in the atmosphere,which have an important influence on the generation of secondary organic aerosols,the formation of cloud condensation nuclei and the pH of atmospheric precipitation.In this study,we used GC-MS and ion chromatography to analyze the concentration and compositional characteristics of small molecular organic acids in the ambient air of both Beijing,a typical urban area,and Maotai Town,Guizhou Province,a typical brewing industry cluster area.Moreover,we also explores the patterns of organic acid concentrations under various weather conditions.The results indicated that the average concentration of total organic acids in the atmosphere of Maotai Town was(46.47±18.81)μg·m^(-3),while in Beijing,it is(22.98±14.27)μg·m^(-3),showing that the organic acids contributed significantly to the total atmospheric acids in Maotai area.Acetic acid was the most abundant small molecule organic acid in the ambient air of both areas,with the concentration of(38.33±16.65)μg·m^(-3) in Maotai town and(11.77±8.45)μg·m^(-3) in Beijing.In Maotai Town,peak concentrations of organic acids in the air are typically observed either from 10:00 to 13:00 or from 16:00 to 19:00,whereas in Beijing,the highest daily concentrations of small molecule organic acids consistently appear between 16:00 and 19:00.In Beijing,with different meteorological conditions,the concentration of organic acids in the ambient air increased with the rise in PM_(2.5),NO_(2),CO,and relative humidity.Conversely,in the Maotai region,the concentrations of small molecule organic acids increase with the increase of NO2 concentration,but decreases with the increase of wind speed.This differential response is largely attributable to variances in topographical features.In Beijing,the organic acids are mainly affected by both regional meteorological factors and automobile exhaust emissions,whereas,in Maotai Town,the effects of localized emission sources are more pronounced.In addition,by comparing the historical changes of formic acid and acetic acid concentrations in the atmosphere of typical Chinese cities such as Beijing,Shenzhen and Shanghai,it has been observed that the concentrations of organic acids are on an upward trend.This indicates a need for future in-depth investigations into the characteristics of organic acid variations in the atmosphere,and the strengthening of ecological and environmental risk prevention and control measures for organic acids.
作者
陈炳蓉
霍美蓉
高宇
张逸
郭敏杰
田启秋
赵泽花
张晓山
王章玮
CHEN Bingrong;HUO Meirong;GAO Yu;ZHANG Yi;GUO Minjie;TIAN Qiqiu;ZHAO Zehua;ZHANG Xiaoshan;WANG Zhangwei(State Key Laboratory of Urban and Regional Ecology,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085;University of Chinese Academy of Sciences,Beijing 100049;Department of Resources and Environment,Moutai Institute,Renhuai 564507;Department of Tourism Management,Moutai Institute,Renhuai 564507)
出处
《环境科学学报》
CAS
CSCD
北大核心
2024年第9期10-20,共11页
Acta Scientiae Circumstantiae
基金
国家自然科学基金(No.42377266,42077345,42077381)。
关键词
有机酸
空气
北京
茅台镇
浓度特征
organic acids
air
Beijing
Maotai Town
concentration characteristics
作者简介
陈炳蓉(1998-),女,E-mail:brchen_st@rcees.ac.cn;王章玮,E-mail:wangzhw@rcees.ac.cn。
