| 摘要: |
| 溶解态有机质（DOM）是湖泊沉积物的重要组分，解析DOM的组成和来源对于深入理解湖泊有机质生物地球化学循环及水体富营养化控制具有重要意义。 本研究于2021年5月和8月采集了大庆市库里泡表层及柱状沉积物样品、泡内水生物样品（浮游藻类、挺水植物和沉水植物）、岸边土壤、陆生C3和C4植物、禽畜粪便以及城镇污水等样品，分析了样品DOM的稳定同位素（δ13C 和 δ15N）组成及三维荧光光谱特征，并利用IsoSource软件计算了不同来源样品对沉积物DOM的贡献率。结果显示：（1）库里泡内表层沉积物DOM的δ13C和δ15N组成存在季节性差异，5月δ13C和δ15N均值分别-25.54‰和9.02‰，8月分别为-26.81‰和8.40‰。（2）库里泡内柱状沉积物DOM的δ13C和δ15N组成在垂直方向存在差异，表层（0~3 cm）δ13C和δ15N均值分别为-26.58‰和9.04‰，深层（3~30cm）均值分别为-25.40‰和10.61‰。（3）表层沉积物DOM的三维荧光组分存在季节性差异。5月类腐殖质荧光组分为主,占比87.89%，HIX和BIX分别为6.27和0.67；8月份蛋白类荧光组分占比49.58%，HIX和BIX指数均值分别为1.72和0.87。（4）表层沉积物DOM来源，5月份外源输入占比61%，以土壤（21.40%）和城镇污水（18.08%）为主；8月内源贡献占比稍高（55.10%），且以挺水植物为为主（48.68%）。（5）柱状沉积物（0~30 cm）不同深度DOM来源组成相近，主要为城镇污水、沉水植物/藻和挺水植物，贡献率均值分别为42.13%、25.07%和18.53%。整体上，库里泡沉积物DOM来源主要受到流域内人类活动及气候特征的影响，本文研究结果能够促进对我国东北地区湖泊沉积物有机质迁移转化及累积规律的理解。 |
| 关键词: 库里泡 沉积物 溶解态有机质 三维荧光光谱-平行因子分析 碳氮稳定同位素 来源解析 |
| DOI： |
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| 基金项目:国家重大科技专项资助 |
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| Composition characteristics and source tracing of Dissolved Organic Matter in a typical lacustrine sediment in Lake Kulipo, northeasten China |
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Huang Yanyu1, Liu Tingting2, Wang Guiyan3, Chu Zhaosheng2, Gaosijia2, Pan Yunfeng1, Zheng Binghui2
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1.School of Pharmaceutical Engineering,Shenyang Pharmaceutical University;2.National Engineering Laboratory for Lake Pollution Control and Ecological Restoration,Chinese Research Academy of Environmental Sciences;3.School of Pharmaceutical Engineering, Shenyang Pharmaceutical University
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| Abstract: |
| Dissolved organic matter (DOM) is one of the important components in lake sediment. Identifying the composition and sources of sediment DOM exerts great significance on the understanding of carbon biogeochemical process and eutrophication control of lake. To trace the source of sediment DOM in Kulipao Lake, samples of sediment and potential sources were collected in May and August 2021, including surface and core sediment samples, phytoplankton, macrophytes, C3 and C4 plants, livestock manure and treated effluent. Stable isotope (δ13C and δ15N) and fluorescence spectroscopy were applied to characterize the DOM composition of sediment and source samples. Furthermore, contribution rates of different sources to surface and core sediment DOM were calculated using IsoSource software. Results suggested that (1) δ13C and δ15N of DOM in surface sediment differed in May (average values of -25.54‰ and 9.02‰) and August (average values of -26.81‰ and 8.40 ‰). (2) δ13C and δ15N of DOM in core sediment differed in depth, with average values of -26.58‰ and 9.04‰ in depth of 0~3 cm and -26.58‰ and 9.04‰ in depth of 3~30 cm. (3) Fluorescence components of surface sediment DOM dominated by humic-like component (87.89%) in May, with HIX and BIX values of 6.27 and 0.67. In August, protein-like component increased to 49.58% with HIX and BIX values of 1.72 and 0.87. (4) Source analysis showed that allochthonous DOM (61%) dominated in surface sediment in May, with soil and treated effluent proportions of 21.40% and18.08%, respectively. In August, proportion of autochthonous DOM increased to 55.10%, with a high contribution of emergent macrophyte (48.68%). (5) DOM sources of core sediment showed no significant variation with depth, with treated effluent, submerged plant/algae and emergent macrophyte dominating the DOM with proportions of 42.13%、25.07% and 18.53%, respectively. In a whole, sources of sediment DOM in Kulipao Lake was mainly related to the human activity and climate feature. Results of this study contributed to the understanding of DOM accumulation and transportation in northeast watershed of China. |
| Key words: Kulipao Lake sediment dissolved organic matter EEM-PARAFAC carbon and nitrogen stable isotope source tracing |
