| 洱海沉积物间隙水中溶解有机质的地球化学特性 |
| |
| 引用本文： | 傅平青,吴丰昌,刘丛强.洱海沉积物间隙水中溶解有机质的地球化学特性[J].水科学进展,2005,16(3):338-344. |
| |
| 作者姓名： | 傅平青 吴丰昌 刘丛强 |
| |
| 作者单位： | 1.中国科学院地球化学研究所环境地球化学国家重点实验室, 贵州, 贵阳, 550002; |
| |
| 基金项目： | 国家自然科学基金资助项目(40403011)，国家重点基础研究发展计划(973)资助项目(2002CB412300)，中国科学院知识创新工程重要方向项目(KZCX3 SW 140)~~ |
| |
| 摘 要： | 对洱海沉积物间隙水中溶解有机质(DOM)含量、紫外可见吸收、荧光以及分子量等的垂直分布特征进行了研究。结果表明,DOC含量在沉积物水界面明显富集,随后急剧下降,6cm处达到最小值,随后呈上升趋势。DOC与吸光度值、荧光发射光谱强度之间具有一定的线性相关关系。DOM的E3/E4值范围在1～6之间,绝大多数在1～35之间。表征DOM中腐殖质来源的指标荧光指数值处于148～159之间,说明DOM以陆源输入为主。此外,洱海沉积物间隙水DOM分子量分布呈多峰分布模式,重均分子量(Mw)值在1462～1953Da之间,数均分子量(Mn)值在547～900Da之间,多分散性系数ρ值在202～305之间。随着沉积深度增大,Mw和Mn有略微的增大趋势,但变化不大。沉积物的氧化还原条件、微生物活动以及铁、锰氧化物等在沉积剖面的差异是控制间隙水中DOM各种地球化学特性的主要因素。
|
| 关 键 词： | 溶解有机质 沉积物间隙水 荧光 高效体积排阻色谱 洱海 地球化学特征 |
| 文章编号： | 1001-6791(2005)03-0338-07 |
| 收稿时间： | 2004-02-25 |
| 修稿时间： | 2004年2月25日 |
Geochemical characteristics of dissolved organic matter in the sediment pore water of Erhai Lake |
| |
| FU Ping-qing,WU Feng-chang,LIU Cong-qiang.Geochemical characteristics of dissolved organic matter in the sediment pore water of Erhai Lake[J].Advances in Water Science,2005,16(3):338-344. |
| |
| Authors: | FU Ping-qing WU Feng-chang LIU Cong-qiang |
| |
| Affiliation: | 1.State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China;2.Graduate School of the Chinese Academy of Sciences, Beijing 100039, China |
| |
| Abstract: | We study the DOC concentrations, the UV-Vis absorbance, fluorescence and the molecular weight of the dissolved organic matter in the sediment pore water of Erhai Lake.DOC concentration has a high value at the sediment-water interface, with a sharp decrease within the depth of 6 cm, and, then, increases later.The vertical distributions of a254, a280 and fluo-rescence intensity at Ex=335 nm are in agree with the distribution of DOC.The E3/E4 values range from.to 6 and most of the values are less than 3.5, which means that the DOM in sediment pore water has relatively high humification, aromaticity and molecular weight.f450/500 values range from 1.48 to 1.59, showing the terrestrial nature of the majority of the sediment pore water DOM.Through the HPSEC results, all the sediment pore water DOM show a multi-modal distribution of the molec-ular weight.Weight-average molecular weight (Mw), which ranges from 1462 to 1953 Da, and number-average molecular weight (Mn), which ranges from 547 to 900 Da, vary a little along the depth and mainly have a trend of increase.The poly-dispersity, ρ (the ration of Mw to Mn) ranges from 2.02 to 3.05, which suggests that the pore water DOM resides in a rela-tively wide size distribution.In general, the geochemical characteristics of sediment pore water DOM are attributed to the changes in redox chemistry occurrs as a function of the sediment depth, partial mineralization of particulate organic matter as a result of the biotic or abiotic reduction and the effect of metal oxide through the dissolution and formation process. |
| |
| Keywords: | dissolved organic matter sediment pore water fluorescence high-performance size exclusion chromatography Erhai Lake geochemical characteristics |
| 本文献已被 CNKI 维普 万方数据 等数据库收录！ |
| 点击此处可从《水科学进展》浏览原始摘要信息 |
|
点击此处可从《水科学进展》下载全文 |
|
