摘要
大气活性氮沉降对陆地和海洋生态系统有重要的影响,对于气溶胶和降雨中硝酸盐沉降通量和硝酸盐氮氧同位素的研究较多,但对NO_(y)(NO、NO_(2)、NO_(3)、N_(2)O_(5)、HNO_(3)和NO_(3)^(−))干沉降通量及其氮氧同位素的研究很少。本研究于2019年8月7日-2019年8月31日在江西省南昌市东华理工大学分昼夜采集了NO_(y)干沉降样品,分析了干沉降样本中硝酸盐浓度,δ^(15)N-NO_(3)−和δ^(18)O-NO_(3)^(−)值,基于干沉降样本中硝酸盐浓度估算了大气NO_(y)干沉降通量。结果表明,南昌市夏季白天NO_(y)干沉降通量(16.0-110.2μg·h^(−1)·m^(−2),均值(42.6±26.1)μg·h^(−1)·m^(−2))高于夜晚(11.9-51.9μg·h^(−1)·m^(−2),均值(26.7±14.1)μg·h^(−1)·m^(−2))。NO_(y)干沉降样品中δ^(18)O-NO_(3)^(−)值在白天(均值为(62.4‰±7.5‰))稍低于夜晚(均值为(66.7‰±4.1‰)),表明白天NO_(y)参与的化学过程与晚上不同。NO_(y)干沉降样品中δ^(15)N-NO_(3)^(−)在白天(−5.8‰-−0.1‰,均值为(−2.0‰±1.4‰))与晚上(−5.0‰-+0.6‰,均值为(−2.0‰±1.2‰))类似,表明机动车尾气是南昌市夏季大气中NO_(x)的主要来源。
Atmospheric reactive nitrogen deposition has important effects on terrestrial and marine ecosystems.Although many studies have focused on the nitrate deposition fluxes and nitrate dual isotopic compositions of aerosol and precipitation,rarely studies reported the NO_(y)(NO_(2),N_(2)O_(5),HNO_(3) and NO_(3)^(−))dry deposition fluxes and nitrogen and oxygen isotopic compositions.In this study,the NO_(y) dry deposition samples were collected during the daytime and at night on the campus of East China University of Technology in Nanchang City from August 7 to 31,2019.Concentration of nitrate,values of δ^(15)N-NO_(3)^(−) and δ^(18)O-NO_(3)^(−)in dry deposition samples were analyzed,and the dry deposition fluxes of NO_(y) were estimated.The estimated NO_(y) dry deposition fluxes during the daytime(from 16.0-110.2μg·h^(−1)·m^(−2) with average of(42.6±26.1)μg·h^(−1)·m^(−2))were higher than these during night(from 11.9-51.9μg·h^(−1)·m^(−2) with mean of(26.7±14.1)μg·h^(−1)·m^(−2)).Values of δ^(18)O-NO_(3)^(−)in daytime(with average of 62.4‰±7.5‰)were lower than these during night(with average of 66.7‰±4.1‰),indicated that the NO_(y) involved atmospheric photochemical oxidation processes in daytime were different from these at night.δ^(15)N-NO_(3)^(−)values in daytime(from−5.8‰to−0.1‰,with mean of(−2.0‰±1.4‰))were similar to these at night(from−5.0‰to+0.6‰,with average of(−2.0‰±1.2‰)),suggested that vehicle exhaust was the main NO_(x) source of in the atmosphere of Nanchang City in summer.
作者
孔露静
尤子昇
张永运
王小嫚
张浩然
刘敏
罗笠
KONG Lujing;YOU Zisheng;ZHANG Yongyun;WANG Xiaoman;ZHANG Haoran;LIU Min;LUO Li(School of Water Resources and Environmental Engineering,East China University of Technology,Nanchang,330013,China;Key Laboratory of Causes and Control of Air Pollution,Jiangxi Province,East China University of Technology,Nanchang,330013,China;Jiangxi Environmental Monitoring Center Station,Nanchang,330029,China;State Key Laboratory of Marine Resource Utilization in South China Sea,Hainan University,Hainan,570228,China)
出处
《环境化学》
CAS
CSCD
北大核心
2021年第11期3501-3509,共9页
Environmental Chemistry
基金
国家自然科学基金(41763001)
江西省教育厅科技项目(GJJ160580)
东华理工大学博士科研启动基金(DHBK2016105)资助。
