川西高原河流水体CDOM对pH的响应特征研究  

Study on Response Characteristics of Chromophoric Dissolved Organic Matter(CDOM)to pH in Natural Rivers in Western Sichuan Plateau

作　　者：刘堰杨 孙辉[2] LIU Yan-yang;SUN Hui(Chengdu Konggang Enviromnent Investment Co.,Ltd,Chengdu 610200,China;College of Architecture and Environment,Sichuan Unwersity,Chengdu 610065,China)

机构地区：[1]成都空港环境投资有限公司,成都610200 [2]四川大学建筑与环境学院,成都610065

出　　处：《四川环境》2022年第6期154-162,共9页Sichuan Environment

基　　金：国家自然科学基金(41271094)。

摘　　要：选取川西高原两种主要地貌类型的高海拔河流共五条,即杂谷脑河、抚边河及岷江(高山峡谷区)与白河、黑河(丘状高原区),采用三维荧光光谱、紫外-可见光吸收光谱、二维相关光谱研究其水体有色溶解性有机质(CDOM)在17天培养前后对pH的响应行为。5条河流CDOM在强酸环境(pH=2)中吸光度较低,高山峡谷区河流CDOM吸光度经培养后均出现上升现象,丘状高原河流则呈现出相反的趋势;5条河流FDOM中具有4种荧光峰,分别是A峰(260/380~460)、C峰(350/380~420)、B峰(275/310)及T峰(275/340)。其中,A、C峰属于类腐殖质物质,T、B分别代表类色氨酸、类酪氨酸物质;5条河流中A、C峰随pH值增高出现了“红移”现象,高山峡谷区河流T、B峰对于pH变化更为敏感,经培养后荧光强度增加。UVA类腐殖质FDOM在pH扰动下的光谱强度动态涨落总程度最强,丘状高原河流强于高山峡谷区河流,杂谷脑河、岷江、黑河FDOM中的类蛋白质峰对pH的扰动响应最快。川西高原是我国主要江河的源头集水区及低温有机碳库的主要分布区,首次运用二维相关光谱揭示高原河流水体有色溶解性有机质(CDOM)对pH的响应特征,对于揭示该地区在全球气候变化背景下水体碳输出形态与转化过程具有重要环境意义。In this paper,a total of five high-altitude rivers of two main landforms in the western Sichuan Plateau were selected,namely,the Zagunao River,the Fubian River,the Minjiang river(alpine valley area),Bai River and Hei River(hilllike plateau area),.three-dimensional fluorescence spectrum,UV-VIS absorption spectrum and two-dimensional correlation spectrum were used to study the environmental behavior of colored dissolved organic matter(CDOM)to pH before and after 17-day culture.The CDOM absorbance of the five rivers was low in the strong acid environment(pH=2).The CDOM absorbance of the rivers in alpine-gorge region increased after incubation,while the CDOM absorbance of the rivers in plateau planation surface showed the opposite trend.Four fluorescent peaks were found in the FDOM of five rivers:A(260/380~460),C(350/380~420)represented UVA humic-like fluorophores,T(275/340)and B(275/310)belonged to protein-like substance.The humic-like fluorescence peaks A,C appears"red shifting"with the increase of pH among the five rivers.The peak B(tyrosine-like)and peak T(tryptophan-like)of the rivers in alpine-gorge region were more sensitive to the change of pH,and the fluorescence intensity increased after culture.The total dynamic fluctuation degree of spectral intensity of UVA humic-like FDOM under pH disturbance was the strongest,the humus plateau river was stronger than the river in alpine canyon area,and the protein-like peak in the FDOM of Zagunao River,Minjiang River and Heihe River showed the fastest response to pH disturbance.The western Sichuan Plateau is the headwaters of major rivers and the main distribution area of low temperature organic carbon pool in China.In this paper,two-dimensional correlation spectroscopy(2 D-COS)was used to accurately reveal the influence of pH on chromophoric dissolved organic matter(CDOM)in rivers from western Sichuan Plateau,which is of great environmental significance to reveal the morphology and transformation process of carbon output in nature water from this region under the back

关 键 词：川西高原 溶解性有机质(DOM) PH 三维荧光光谱 二维相关光谱(2D-COS) 

分 类 号：X144[环境科学与工程—环境科学]