秋季长江口海域海水和大气中BTEX的分布及环境效应  

Distributions and environmental effects of BTEX in seawater and atmosphere in the Yangtze River Estuary during autumn

作　　者：李云飞 乔浩 王健[2] 陈岩[2] 张洪海[1,2] LI Yunfei;QIAO Hao;WANG Jian;CHEN Yan;ZHANG Honghai(Frontiers Science Center for Deep Ocean Multispheres and Earth System,the Key Laboratory of Marine Chemistry Theory and Technology,Ministry of Education,Ocean University of China,Qingdao 266100;College of Chemistry and Chemical Engineering,Ocean University of China,Qingdao 266100)

机构地区：[1]中国海洋大学,深海圈层与地球系统前沿交叉中心,海洋化学理论与工程技术教育部重点实验室,青岛266100 [2]中国海洋大学化学化工学院,青岛266100

出　　处：《环境科学学报》2023年第7期264-272,共9页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金(No.41876082,42276042)。

摘　　要：以苯、甲苯、乙苯、间/对二甲苯和邻二甲苯为代表(简称BTEX)的单环芳烃是大气中挥发性有机物(VOCs)的重要组分,它们对臭氧(O3)和二次有机气溶胶(SOA)的生成具有重要作用.于2020年10月分析了长江口及邻近海域海水和大气中BTEX的分布特征,并评估了其海-气通量及大气环境效应.结果表明,研究海域表层海水中苯、甲苯、乙苯、间/对二甲苯和邻二甲苯的浓度平均值分别为(17.4±21.9)、(91.2±64.0)、(25.9±16.9)、(52.9±34.9)和(26.7±19.3)ng·L^(-1).BTEX浓度总体呈现近岸高、外海低的分布趋势,底层海水浓度略高于表层.大气中苯、甲苯、乙苯、间/对二甲苯和邻二甲苯的平均浓度分别为(90.4±46.6)×10^(-12)、(255±284)×10^(-12)、(139±115)×10^(-12)、(196±202)×10^(-12)和(131±116)×10^(-12),在舟山群岛附近海域浓度较高.大气中乙苯和二甲苯浓度表现出显著的相关性,表明它们具有相似的来源.长江口海域BTEX海-气通量为22.7~3737 g·km^(-2)·d^(-1),表明调查海域是上方大气中BTEX重要的源.通过O3和SOA生成潜势的计算,发现间/对二甲苯和甲苯是大气BTEX的关键活性组分,它们对环境效应的影响最为显著.Monocyclic aromatic hydrocarbons,represented by benzene,toluene,ethylbenzene,m-,p-xylene and o-xylene(BTEX)are important components of volatile organic compounds(VOCs)in the atmosphere,which play an important role in the formations of ozone(O3)and secondary organic aerosols(SOA).The distribution characteristics of BTEX in seawater and atmosphere were analyzed in the Yangtze River Estuary and adjacent areas in October 2020,and the sea-air fluxes and atmospheric environmental effects were also assessed.The average concentrations of benzene,toluene,ethylbenzene,m-,p-xylene and o-xylene in the surface seawater were(17.4±21.9),(91.2±64.0),(25.9±16.9),(52.9±34.9)and(26.7±19.3)ng·L^(-1),respectively.The concentrations of BTEX near shore were higher than those in the open sea.The concentrations in the bottom seawater were slightly higher than those in the surface seawater.The concentrations of benzene,toluene,ethylbenzene,m-,p-xylene and o-xylene in the atmosphere were(90.4±46.6),(255±284),(139±115),(196±202)and(131±116)part per trillion by volume,respectively,with the higher values appearing at the Zhoushan Islands.A positive correlation between ethylbenzene and xylene concentrations was observed in the atmosphere,suggesting that there were some common sources.The sea-air fluxes of BTEX ranged from 22.7 to 3737 g·km^(-2)·d^(-1),indicating that the Yangtze River Estuary is an important source of regional atmospheric BTEX.Through the calculation of the generation potentials of O3 and SOA,it was found that m-,p-xylene and toluene were the key active components of BTEX in the atmosphere,and they had the most significant atmospheric environmental effects.

关 键 词：单环苯系物 分布 海-气通量 环境效应 长江口 秋季 

分 类 号：X831[环境科学与工程—环境工程]