不同环境功能区大气颗粒物中水溶性有机碳的污染特征及其吸光性研究  

Pollution characterization of water-soluble organic carbon in atmospheric particulate matter and its light absorption in different environmental function areas

作　　者：丁润萍 程振宇 陆国繁 彭琬钰 韦玉贵 幸娇萍 叶清[1,2] 刘苑秋[1,2] 王燕[1,2] DING Runping;CHENG Zhenyu;LU Guofan;PENG Wanyu;WEI Yugui;XING Jiaoping;YE Qing;LIU Yuanqiu;WANG Yan(Key Laboratory of Forest Ecosystem Protection and Restoration of Poyang Lake Basin,State Forestry and Grassland Bureau,Jiangxi Agricultural University,Nanchang 330045;College of Forestry,Jiangxi Agricultural University,Nanchang 330045)

机构地区：[1]江西农业大学,鄱阳湖流域森林生态系统保护与修复国家林业和草原局重点实验室,南昌330045 [2]江西农业大学林学院,南昌330045

出　　处：《环境科学学报》2024年第4期252-262,共11页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金(No.42065007)。

摘　　要：为了探究不同环境功能区水溶性有机碳(WSOC)光学特性的差异及其影响因素,本研究采集了江西农业大学(城区)、南昌梅岭森林公园(郊区)和庐山风景区(背景点)的大气细颗粒物(PM_(2.5))样品.采用总有机碳分析仪和紫外可见分光光度计对WSOC浓度及吸光系数(Abs_(365))、质量吸收效率(MAE_(365))和吸收波长指数(AAE)进行测量与估算.结果表明,城区、郊区和背景点均存在不同程度的PM_(2.5)污染,浓度水平呈城区>郊区>背景点的趋势.WSOC浓度水平呈郊区>城区>背景点的趋势,郊区和城区WSOC浓度与PM_(2.5)浓度有显著的相关性,而背景点没有显著相关性,说明城区和郊区的WSOC与PM_(2.5)颗粒物来源更具有同源性.WSOC的Abs_(365)呈城区>郊区>背景点的特点,3个观测点WSOC均存在一定量的吸光性物质,且城区的WSOC含有更多的吸光性物质.WSOC的MAE_(365)呈城区>背景点≈郊区的特点,说明城区的WSOC中有更强吸光性物质.郊区和背景点WSOC的MAE_(365)值相近,说明虽然背景点WSOC中含有较少的吸光性物质,但其含有的吸光性物质具有更强的吸光能力.3个观测点WSOC的AAE值接近,但分布范围有所不同.郊区的AAE值变化范围较大,WSOC的来源可能更为复杂.城区和背景点的AAE分布在4.7~7.0水平的占比较大,说明二次有机气溶胶(SOA)可能是城区和背景点WSOC的主要来源.WSOC的Abs_(365)与WSOC含量有关,随污染程度增加而增加.而WSOC的MAE_(365)与WSOC含量和Abs_(365)大小无关,高污染水平下不一定具有高MAE_(365).高污染水平下WSOC的吸光性更倾向于短波长,且污染水平越高,WSOC的Abs、MAE的波长依赖性越强.In this study,PM_(2.5) samples were collected at Jiangxi Agricultural University (urban site),Nanchang Meiling Forest Park (suburban site),and Lushan Scenic Area (background site) in order to investigate the differences in the optical properties of water-soluble organic carbon (WSOC) in different environmental functional areas and their influencing factors.A total organic carbon analyser was used to measure the WSOC concentration,and a UV-visible spectrophotometer was used to estimate the absorbance coefficient (Abs_(365)),mass absorption efficiency (MAE_(365)),and absorption wavelength index (AAE).The results showed that PM_(2.5) pollution was different among urban,suburban and background sites,and the WSOC concentration levels were suburban>urban>background sites.There was a significant correlation between WSOC concentration and PM_(2.5) concentration in the suburban and urban sites,while there was no significant correlation in the background site,indicating that WSOC in urban and suburban sites are more homologous to PM_(2.5) particulate matter sources.Abs_(365) was urban>suburban>background sites for WSOC.There were a certain number of lightabsorbing substances in WSOC at all three observation sites,and WSOC in urban sites contained more light-absorbing substances.MAE_(365) was urban>background sites≈suburban,indicating that there were more light-absorbing substances.The similar MAE_(365) values for the WSOC in the suburbs and the background sites indicated that although the WSOC in the background site contained less light-absorbing substances,the lightabsorbing substances had stronger light-absorbing capacity.The AAE values of the three observation sites WSOC were close to each other,but the distribution ranges were different.The AAE values of the suburban sites had a larger range of variation,and the source of WSOC might be more complex.The AAE distributions of urban and background sites had a larger percentage of 4.7~7.0 levels,indicating that SOA might be the main source of WSOC in urban and background

关 键 词：PM_(2.5) 水溶性有机碳(WSOC) 光学特性 不同环境功能区 

分 类 号：X513[环境科学与工程—环境工程] X831