高寒湖泊表层沉积物有机质的组分特征  

Compositional characteristics of organic matter in surface sediments of alpine lakes

作　　者：赵李佳 张文强[1,3] 单保庆 张殿伟[1,3] 魏东洋 李杰 ZHAO Lijia;ZHANG Wenqiang;SHAN Baoqing;ZHANG Dianwei;WEI Dongyang;LI Jie(Key Laboratory of Environmental Aquatic Chemistry,Research Center for Eco~Environment Sciences,Beijing 100085,China;School of Environmental and Municipal Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院生态环境研究中心,环境水质学国家重点实验室,北京100085 [2]兰州交通大学环境与市政工程学院,兰州730070 [3]中国科学院大学,北京101408

出　　处：《环境工程学报》2024年第12期3445-3453,共9页Chinese Journal of Environmental Engineering

基　　金：国家重点研发计划项目(2022YFC3204003)。

摘　　要：湖泊沉积物是全球碳循环过程的重要组成部分。高纬度地区气候寒冷,光照辐射较少,具有特殊的地理位置和气候环境,其沉积物有机质的赋存和迁移特征更容易受气候环境的影响。本研究以东北地区高寒湖泊大力加湖为例,采用有机质的连续提取法、碳氮比值(C/N)、δ^(13)C和δ^(15)N稳定同位素、三维荧光和紫外光光谱技术对大力加湖有机质空间分布、组分、来源和理化性质进行研究。结果表明:沉积物中有机质含量为2.26%~12.04%,平均值为6.88%,空间分布呈现湖心向两侧递减的趋势。有机质分级提取出:水提取态(WEOM)、富里酸(FA)、胡敏酸(HA)和胡敏素(HM)4种主要组分,其含量比例为1∶4.6∶11.3∶24.8;WEOM中共鉴别出4个荧光组分:2个类蛋白组分(C1、C2)、1个类蛋白和类腐殖质混合物(C3)、1个类腐殖质组分(C4),其中C1以类酪氨酸荧光峰为主、C2以低激发态酪氨酸荧光峰为主、C3以类酪氨酸和类富里酸混合为主、C4以类腐殖酸为主;有机质C/N和稳定同位素δ^(13)C、δ^(15)N含量分别为8.57~14.08、−30.129‰~−28.288‰和4.427‰~9.106‰,表明有机质来源为陆源与自生源相互作用,根据荧光积分类蛋白组分占据总体的74.92%,说明有机质来源主要以自生源输入为主,腐殖化程度低。本研究揭示的大力加湖表层沉积物有机质的分布、组成及赋存特征等可为深入研究高寒湖泊有机质在气候变化和碳中和背景下的作用和高寒湖泊治理策略制定提供一定研究依据。Lake sediments are pivotal in the global cycle.Particularly for those in high-latitude regions characterized by frigid climates and diminished solar radiation,the occurrence and migration characteristics of organic matters within them are easy affected by the climate and environment due to the unique geographic and climatic attributes.In this study,the alpine Dalijia Lake in Northeast China was taken as an example,then continuous extraction of organic matter,analysis of the carbon-nitrogen ratio(C/N),stable isotope analysis(δ^(13)C andδ^(15)N),three-dimensional fluorescence spectroscopy and ultraviolet spectroscopy were used to determine the spatial-temporal distribution,compositional characteristics,genesis and physicochemical properties of organic matter in Dalijia Lake sediments.The results showed that organic matter content in the sediments varies from 2.26%to 12.04%,with an average value of 6.88%,and a diminution tendency occurred from the central region towards the peripheries of the lake.Four principal constituents of organic matter were discerned:water-extractable organic matter(WEOM),fulvic acid(FA),humic acid(HA),and huminin(HM),and their content ratio was 1∶4.6∶11.3∶24.8.In WEOM,four fluorescent components were identified as follows:two protein-like fractions(C1 and C2),a combination of protein like fraction and huminin-like fraction(C3),a huminin-like fraction(C4),of which C1 is dominated by tyrosine fluorescent peak,C2 is dominated by low excited state tyrosine fluorescent peak,C3 predominantly features tyrosine-like and fulvic acid-like substances,C4 is chiefly composed of humic acid.The C/N ratio andδ^(13)C andδ^(15)N values of the organic matter were 8.57 to 14.08,−30.129‰to−28.288‰,and 4.427‰to 9.106‰,respectively.These metrics suggest a terrestrial autotrophic origin for the organic matter,based on the fluorescence integration,the protein-like components approximately accounted for 74.92%of total organic matter.This indicated a predominantly autogenous input for the organic

关 键 词：大力加湖 沉积物 有机质分级 空间分布 

分 类 号：X524[环境科学与工程—环境工程]