引用本文: | 赖安兴,王洪伟,谢珂,顾于,李化炳,王丽娜,李彪,吴庆龙.长江中下游湖泊沉积物厌氧铁氨氧化过程及脱氮贡献.湖泊科学,2024,36(6):1743-1756. DOI:10.18307/2024.0622 |
| Lai Anxing,Wang Hongwei,Xie Ke,Gu Yu,Li Huabing,Wang Lina,Li Biao,Wu Qinglong.The feammox mechanism within lake sediments in the middle and lower Yangtze River basin and its contribution to nitrogen removal. J. Lake Sci.2024,36(6):1743-1756. DOI:10.18307/2024.0622 |
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长江中下游湖泊沉积物厌氧铁氨氧化过程及脱氮贡献 |
赖安兴1,2, 王洪伟1,2, 谢珂1,2, 顾于1,3, 李化炳1, 王丽娜1, 李彪1, 吴庆龙1,4,5
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1.中国科学院南京地理与湖泊研究所, 湖泊与流域水安全重点实验室, 南京 210008;2.中国科学院大学, 北京 100049;3.南京师范大学地理科学学院, 南京 210023;4.中国科学院抚仙湖高原深水湖泊研究站/抚仙湖高原深水湖泊云南省野外科学观测站, 澄江 652500;5.南方海洋科学与工程广东省实验室, 广州 511548
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摘要: |
湖泊氮素污染问题严重,水体富营养化程度正在日益加剧。湖泊沉积物中传统脱氮过程的研究主要关注反硝化和厌氧氨氧化过程,而厌氧铁氨氧化过程(feammox)的发现更新了人们对于氮素转换途径的认识,也使得湖泊沉积物中各个脱氮途径的贡献至今尚不明确。本研究通过15N稳定同位素示踪技术定量了长江中下游18个湖泊沉积物反硝化、厌氧氨氧化和厌氧铁氨氧化过程的速率,计算了各个过程的脱氮贡献。结果显示,冬季反硝化、厌氧氨氧化和厌氧铁氨氧化的平均速率分别为(2.38±0.80)、(0.06±0.04)和(0.015±0.025) mg/(kg·d),平均脱氮贡献分别为96.5%±2.4%、2.7%±2.0%和0.8%±1.4%;夏季反硝化、厌氧氨氧化和厌氧铁氨氧化的平均脱氮速率分别为(2.54±1.04)、(0.12±0.06)和(0.005±0.005) mg/(kg·d),平均脱氮贡献分别为95.0%±3.4%、4.8%±3.2%和0.2%±0.3%。尽管厌氧铁氨氧化过程对于总体氮素脱除的贡献较为有限,但对NH+4的脱除贡献值得关注,其NH+4脱除贡献率在冬季和夏季分别为15.5%±23.4%和13.4%±22.4%。在冬季的洪湖、西凉湖和斧头湖以及夏季的鄱阳湖中厌氧铁氨氧化的NH+4脱除贡献率甚至高于厌氧氨氧化,表明厌氧铁氨氧化过程在沉积物NH+4脱除中的作用不容忽视。多元统计分析结果表明,pH、硝态氮、总有机碳和总无机碳可能是厌氧铁氨氧化过程的主要影响因素。本研究丰富了湖泊生态系统氮循环路径的认识,明确了湖泊生态系统氮素的转化过程和环境归趋,为湖泊生态系统氮素管理与水体富营养化治理提供了重要的理论支撑。 |
关键词: 反硝化 厌氧氨氧化 厌氧铁氨氧化 同位素示踪技术 脱氮贡献 长江中下游湖泊 |
DOI:10.18307/2024.0622 |
分类号: |
基金项目:国家自然科学基金项目(U2040201,32201334,32101311)和南方海洋科学与工程广东省实验室(广州)项目(GML20220017)联合资助。 |
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The feammox mechanism within lake sediments in the middle and lower Yangtze River basin and its contribution to nitrogen removal |
Lai Anxing1,2, Wang Hongwei1,2, Xie Ke1,2, Gu Yu1,3, Li Huabing1, Wang Lina1, Li Biao1, Wu Qinglong1,4,5
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1.Key Laboratory of Lake and Watershed Science for Water Security, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, P. R. China;2.University of Chinese Academy of Sciences, Beijing 100049, P. R. China;3.School of Geographical Sciences, Nanjing Normal University, Nanjing 210023, P. R. China;4.Fuxianhu Research Station for Alpine Deep Lake, Fuxianhu Observation Station of Yunnan Province, Chengjiang 652500, P. R. China;5.Southern Marine Sciences and Engineering Guangdong Laboratory(Guangzhou), Guangzhou 511548, P. R. China
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Abstract: |
Nitrogen pollution in lakes poses a significant challenge. Historically, researches on nitrogen removal from lake sediments has concentrated on denitrification and anaerobic ammonium oxidation(anammox) processes. The recent discovery of anaerobic ammonium oxidation coupled to iron(Ⅲ) reduction (feammox) had expanded our understanding of nitrogen transformation pathways, leaving the specific contributions of each nitrogen removal process in lake sediments still unclear. This study quantitatively assessed the rates of denitrification, anammox, and feammox in the sediments of 18 lakes located in the middle and lower reaches of the Yangtze River utilizing the 15N stable isotope tracing technique. We then estimated the nitrogen removal efficiency attributed to each process. The findings revealed that the average denitrification, anammox, and Feammox rates in winter were (2.38±0.80) mg/(kg·d), (0.06±0.04) mg/(kg·d), and (0.015±0.025) mg/(kg·d), respectively, contributing to 96.5%±2.4%, 2.7%±2.0%, and 0.8%±1.4% of nitrogen removal. During summer, the rates were (2.54±1.04) mg/(kg·d), (0.12±0.06) mg/(kg·d) and (0.005±0.005) mg/(kg·d), respectively, with contributions of 95.0%±3.4%, 4.8%±3.2%, and 0.2%±0.3%. Despite the relatively minor role of feammox in overall nitrogen removal, its significance in NH+4 elimination is noteworthy, accounting for 15.5%±23.4% in winter and 13.4%±22.4% in summer. Notably, in Lake Honghu, Lake Xiliang, and Lake Futou in winter, and in Lake Poyang in summer, feammox's contribution to NH+4 removal exceeded that of anammox, underscoring the importance of feammox in sediment NH+4 removal. Multivariate statistical analysis suggested that pH, nitrate, total organic carbon, and total inorganic carbon were key factors influencing feammox activity. This study enhanced our comprehension of nitrogen cycling pathways within lake ecosystems, elucidated the transformation processes and environmental fate of nitrogen, and provided crucial theoretical support for managing nitrogen and controlling eutrophication in these environments. |
Key words: Denitrification anammox feammox stable isotope tracing nitrogen removal lakes in middle and lower reaches of the Yangtze River |
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