环境工程学报2024，Vol.18Issue(12)：3445-3453,9.DOI:10.12030/j.cjee.202312009
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
摘要
Abstract
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(δ13C and δ15N),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 and δ13C and δ15N 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 matter with a relatively low level of humification.The results of composition,distribution and occurrence of organic matters in surface sediments of alpine Dalijia Lake in this study can provide a support for the deep study of the function of organic matter in alpine lakes under the background of calimate change and carbon neutralization and making a strategy on alpine lake control.关键词
大力加湖/沉积物/有机质分级/空间分布Key words
dalijia lake/sediment/organic matter grading/spatial distribution分类
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赵李佳,张文强,单保庆,张殿伟,魏东洋,李杰..高寒湖泊表层沉积物有机质的组分特征[J].环境工程学报,2024,18(12):3445-3453,9.基金项目
国家重点研发计划项目(2022YFC3204003) （2022YFC3204003）
