| 摘要: |
| 本研究旨在系统分析太湖不同区域沉积物中腐殖酸(humic acid, HA)的空间分布特征及其对甲烷生成过程的影响。采样区域涵盖东太湖、梅梁湾、湖心区和大浦口,分别采集表层沉积物进行定量分析。通过傅里叶红外光谱(FTIR)、分光光度法、元素分析、电化学测量以及醌类基团的定量测试,表征了HA的含量、结构特征及氧化还原特性(包括电子接受能力(electron accepting capacity, EAC)和电子供给能力(electron donating capacity, EDC))。研究结果表明,太湖不同区域的HA含量及其氧化还原特性存在显著空间差异。草型湖区(如东太湖)的HA的含量较高,主要由于其沉积物中富含类纤维素、类木质素物质；而藻型湖区(如梅梁湾)的HA的前驱体具有更多的蛋白质等含氮物质,因此具有更高的氮含量。藻型湖区的HA表现出更强的EAC。相关性分析显示,HA的EAC与沉积物碳氮比呈显著负相关以及HA的芳香缩合度呈显著正相关。为了进一步明确太湖HA对产甲烷过程的影响,本研究在富集体系中探究了不同EAC的HA对甲烷生成的调控作用,并通过测定甲烷累积量和辅酶F420相对活性来表征产甲烷过程。结果表明,随着HA的EAC增加,其对产甲烷过程的抑制作用越强,辅酶F420相对活性显著降低。这一发现表明湖泊HA能够通过其氧化还原特性在调控CH4排放方面起着关键作用。未来的研究应进一步关注不同前驱体对湖泊HA形成机制的影响,以及影响HA的EAC的关键因素,以全面理解湖泊HA在气候变化调控中的潜在作用。 |
| 关键词: 腐殖酸 电子接受能力 产甲烷 太湖 藻型湖区 草型湖区 |
| DOI： |
| 分类号: |
| 基金项目:江苏省自然科学(BK20220015),国家自然科学(92251304) |
|
| Spatial Distribution Characteristics of Humic Acid in Lake Taihu Sediments and Its Influence on Methanogenesis |
|
Zhou Wenjie,Wang Hongwei,Zhao Cheng,Xun Fan,Han Xuexin,Xu Yan,Xing Peng
|
|
1.School of Civil Engineering,Southeast University;2.Nanjing Institute of Geography & Limnology, CAS
|
| Abstract: |
| This study aims to systematically analyze the spatial distribution characteristics of humic acid (HA) in sediments from different regions of Lake Taihu and its influence on methane production. Surface sediment samples were collected from Dongtaihu Lake, Meiliang Bay, the central lake area, and Dapukou for quantitative analysis. Fourier-transform infrared spectroscopy (FTIR), spectrophotometry, elemental analysis, electrochemical measurements, and quinone group quantification were employed to characterize the HA content, structural properties, and redox characteristics, including electron accepting capacity (EAC) and electron donating capacity (EDC). |
| Key words: Humic acid electron accepting capacity methane production Lake Taihu algal-dominated regions macrophyte-dominated regions |
