基于UV-Vis和EEM-PARAFAC的草海沉积物DOM时空分布特征  

Spatial and Temporal Distribution Characteristics of DOM in Sediments from Guizhou Caohai Based on UV-Vis and EEM-PARAFAC

作　　者：龙云川[1,2] 王龙燕 胡菁 蒋娟 LONG Yunchuan;WANG Longyan;HU Jing;JIANG Juan(Guizhou Institute of Biology,Guizhou Academy of Sciences,Guiyang 550009,China;Caohai Ecological Research Station,Guizhou Academy of Sciences,Weining 553100,China;College of Resource and Environmental Engineering,Guizhou University,Guiyang 550025,China)

机构地区：[1]贵州科学院贵州省生物研究所,贵州贵阳550009 [2]贵州科学院草海生态站,贵州威宁553100 [3]贵州大学资源与环境工程学院,贵州贵阳550025

出　　处：《环境科学研究》2024年第12期2698-2709,共12页Research of Environmental Sciences

基　　金：贵州省基础研究计划项目(黔科合基础ZK[2023]一般233);国家自然科学基金项目(No.32360036);贵州科学院博士科研启动项目(黔科院R字[2023]02号)。

摘　　要：为揭示高原湿地贵州草海沉积物溶解性有机质(DOM)不同水期的时空演变特征及影响因素,本文利用紫外可见吸收光谱(UV-Vis)、三维荧光光谱结合平行因子分析(EEM-PARAFAC)解析贵州草海枯水期和丰水期沉积物DOM含量、分子性质、来源及荧光组分。结果表明:①草海沉积物中DOM含量为0.79~5.14 mg/g,包含类蛋白(C1)和类腐殖质(C2)两种荧光组分,其中C1为优势组分,其平均荧光强度占比为78.01%。DOM以弱腐殖化特征的富里酸类物质为主,呈现内源为主、陆源为辅的混合来源特征,生物可利用性较高。②除DOM自生源特性外,丰水期沉积物DOM含量、相对浓度、腐殖化程度、芳香度、官能团数均低于枯水期。枯水期各组分的高荧光强度值出现在草海湖心区域及东北区域,可能与草海湖泊地形及北部城市人类活动有关;丰水期C2组分在南部湖滨区域聚集,可能与草海南部农业径流相关。③相关性分析、共现网络分析及Mantel test分析表明,TOC含量、TP含量及CAT酶活性均与DOM组分呈显著相关,人类活动及微生物作用介导着枯水期DOM特征,丰水期DOM来源可能还受风浪扰动、光降解等更多因素影响。研究显示,草海沉积物DOM以类蛋白组分为主、呈弱腐殖化特征、可生化利用性好,需警惕水华暴发风险。To reveal the spatio-temporal evolution characteristics and influencing factors of dissolved organic matter(DOM)in sediments from plateau wetland-Guizhou Caohai during different water periods,ultraviolet-visible absorption spectrum(UV-Vis),threedimensional excitation-emission matrix(EEM)fluorescence spectroscopy,and parallel factor analysis(PARAFAC)were used to analyze the DOM content,source,molecular properties,and fluorescence components in sediments from Caohai during dry and wet periods to provide a theoretical basis for understanding substance cycling and aquatic ecological protection in plateau wetlands.The results showed that DOM concentration in sediments ranged from 0.79 to 5.14 mg/g,and it contained two fluorescence components:protein-like(C1)and humus-like(C2),among which C1 was the dominant component with the average fluorescence intensity of 78.01%.The DOM was predominantly composed of fulvic acids,exhibiting weak humification characteristics and a combination of endogenous and terrigenous origins with high bioavailability.The content,relative concentration,degree of humification,aromaticity,and number of functional groups of DOM in sediments were lower in the wet season than in the dry season,while the autogenetic characteristics were stronger in the wet season.The high fluorescence intensity of fluorescence components was observed in the central and northeastern area of Caohai during the dry season,which might be related to the topography of Caohai Lake and human activities in the northern cities.The C2 component concentrated in the southern lakeside area in the wet season,probably due to agricultural runoff in the southern Caohai.Correlation analyses,co-occurrence network,and Mantel test showed that the TOC,TP and CAT enzyme activity were significantly correlated with DOM components.Human activities and microbial processes influenced DOM characteristics in the dry season,whereas it might also be affected by more factors such as wind-wave disturbance and photodegradation in the wet season.The study

关 键 词：高原湖泊 三维荧光光谱 溶解性有机质(DOM) 紫外可见光谱 分子性质 

分 类 号：X524[环境科学与工程—环境工程]