School of Environment and Planning, University of Liaocheng, Liaocheng 252000, China; College of Water Science, Beijing Normal University, Beijing 100875, China.
School of Environment and Planning, University of Liaocheng, Liaocheng 252000, China; Taihu Laboratory for Lake Ecosystem Research, State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
Environ Pollut. 2020 Jun;261:113644. doi: 10.1016/j.envpol.2019.113644. Epub 2019 Nov 19.
Sediment dissolved organic matter (DOM) was collected in November 2018 from Lake Dongping, China. The lake was divided into the entrance of the Dawen River, the open region of the lake, the tourism district and the macrophyte-dominated region based on principal component analysis (PCA) of 9 DOM-related parameters. Multispectroscopic tools were used to investigate the binding of zinc (Zn) with four kinds of DOM collected from the entrance of the Dawen River (EDOM), the open area of the lake (ODOM), the macrophyte-dominated area (mainly dominated by Potamogeton crispus L.) (PDOM) and the tourism district (TDOM). Three fluorescent components, the humic-like (components 1 and 3) and protein-like (component 2) components, were found by excitation-emission matrix spectra with parallel factor analysis. The EDOM, ODOM and TDOM were controlled by protein-like components, and the PDOM was controlled by humic-like components. Different components respond differently to Zn addition. The binding order of the tyrosine-like fraction > the tryptophan fraction > the humic-like fraction was identified by Synchronous fluorescence (SF) spectra and two-dimensional correlation spectroscopy (2D-COS). The fluorescence intensity of the protein-like component was suppressed, and the humic-like component was enhanced with the addition of Zn. The effective quenching constants (log K) of the protein-like component in PDOM were clearly higher than those in the EDOM, ODOM and TDOM, indicating higher metal binding potential in PDOM than in other kinds of DOM in Lake Dongping. The %F (the amounts of each component measured as % of the total fluorescence maxima for the three components) of the humic-like components exhibited a gradual increase in all kinds of DOM with the addition of Zn, suggesting that the addition of Zn increased the humification of DOM.
2018 年 11 月，在中国东平湖采集了溶解态有机物质（DOM）。根据 9 个与 DOM 相关参数的主成分分析（PCA），将该湖分为大汶河入口、湖区开阔区、旅游区和大型植物主导区。采用多光谱技术研究了从大汶河入口（EDOM）、湖区开阔区（ODOM）、大型植物主导区（主要由菹草（Potamogeton crispus L.）主导）（PDOM）和旅游区（TDOM）采集的四种 DOM 与锌（Zn）的结合情况。通过激发-发射矩阵光谱与平行因子分析发现了三种荧光组分，即腐殖质样（组分 1 和 3）和蛋白质样（组分 2）组分。EDOM、ODOM 和 TDOM 受蛋白质样组分控制，PDOM 受腐殖质样组分控制。不同的组分对 Zn 加入的响应不同。通过同步荧光（SF）光谱和二维相关光谱（2D-COS）确定了酪氨酸样部分>色氨酸部分>腐殖质样部分的结合顺序。随着 Zn 的加入，蛋白质样组分的荧光强度受到抑制，腐殖质样组分增强。PDOM 中蛋白质样组分的有效猝灭常数（log K）明显高于 EDOM、ODOM 和 TDOM，表明 PDOM 中 DOM 的金属结合潜力高于东平湖中的其他类型的 DOM。随着 Zn 的加入，所有类型的 DOM 中腐殖质样组分的 %F（作为三个组分的总荧光最大值的每个组分的量）逐渐增加，表明 Zn 的加入增加了 DOM 的腐殖化程度。
