研究报告

  • 聂明华,刘慧慧,熊小英,晏彩霞,刘冲,徐健.南昌市湖泊水体中不同粒径胶体的三维荧光光谱特征研究[J].环境科学学报,2018,38(5):1929-1938

  • 南昌市湖泊水体中不同粒径胶体的三维荧光光谱特征研究
  • Fluorescence characterization of fractionated colloids in the lakes of Nanchang City
  • 基金项目:国家自然科学基金(No.41601521,41601523);江西省自然科学基金(No.20161BAB213079,20161BAB213077);鄱阳湖湿地与流域研究教育部重点实验室开放基金(No.PK2016006);江西省教育厅科技计划项目(No.GJJ150307,GJJ160320);江西师范大学博士启动基金
  • 作者
  • 单位
  • 聂明华
  • 江西师范大学地理与环境学院, 鄱阳湖湿地与流域研究教育部重点实验室, 南昌 330022
  • 刘慧慧
  • 江西师范大学地理与环境学院, 鄱阳湖湿地与流域研究教育部重点实验室, 南昌 330022
  • 熊小英
  • 江西师范大学地理与环境学院, 鄱阳湖湿地与流域研究教育部重点实验室, 南昌 330022
  • 晏彩霞
  • 江西师范大学地理与环境学院, 鄱阳湖湿地与流域研究教育部重点实验室, 南昌 330022
  • 刘冲
  • 江西师范大学地理与环境学院, 鄱阳湖湿地与流域研究教育部重点实验室, 南昌 330022
  • 徐健
  • 江西师范大学地理与环境学院, 鄱阳湖湿地与流域研究教育部重点实验室, 南昌 330022
  • 摘要:基于切向流超滤系统及三维荧光光谱(3D-EEM)技术,结合平行因子分析法(PARAFAC)及自组织映射神经网络(SOM),对南昌市典型湖泊水体中不同粒径胶体的荧光物质组分、来源及结构等进行分析.通过PARAFAC解谱发现,各粒径胶体主要由5种荧光组分组成,即类腐殖质组分(C1~C3)及类蛋白质组分(C4~C5).其中,类腐殖质组分主要集中在小分子量(1~10 kDa)胶体中,而类蛋白质组分则主要存在于大分子量(100 kDa~0.45 μm)胶体中.同时,利用光谱指数(FI、BIX、HIX、UV254)表征胶体组分来源及其特性,结果表明,大分子量胶体以自生源为主,而小分子量胶体的腐殖化程度及芳香性更高,这与其较高比例的类腐殖质组分有关.经SOM训练,探讨了不同粒径分级胶体在SOM映射图中的分布情况,其结果与PARAFAC所得结果一致,即小分子量胶体及大分子量胶体主要分别映射于SOM的下部和上部,而类蛋白质荧光峰强度占总荧光强度的比例为自右上至左下方向递减.PARAFAC与SOM的有效结合,可为了解水体中的物质组成、掌握胶体在水环境中的环境行为及其与污染物在水体中的归趋作用提供数据支持.
  • Abstract:Based on the parallel factor analysis (PARAFAC) and self-organizing map (SOM), the fluorescence characterization of fractionated colloids in the lakes of Nanchang City was processed using cross-flow ultrafiltration systems and three-dimension excitation-emission matrix fluorescence spectroscopy (3D-EEM). In this study, five fluorescence components were extracted by PARAFAC, including three humic-like components (C1~C3) and two protein-like components (C4~C5), of which humic-and protein-like were mainly in 1~10 kDa and 100 kDa~0.45 μm fractions, respectively. In addition, SOM was employed to explore the distribution of the fluorescence character in different size fractions of colloids, and the results in SOM were consistent with that in PARAFAC, i.e. <1 kDa and 100 kDa~0.45 μm fractions was located in the bottom and upper side of the map, and the proportion of the protein-like fluorescence in the total fluorescence intensity decreased from the upper-right corner to the bottom-left corner. Combining PARAFAC and SOM can help to provide a scientific basis for understanding the composition and fate of colloids and the interaction between contaminants and colloids in aquatic environments. Finally, spectral indices (including FI, the index of recent autochthonous contribution-BIX, humification index-HIX and UV254) were introduced to discover the source and spectral characteristic for the different size fractions of colloids. It revealed that the relatively large colloids were dominated by the recent autochthonous organic matter, while the relatively small colloids were characterized with higher aromaticity and hydrophobicity due to the relatively higher proportion of humic-like components.

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