Abstract Interaction between dissolved organic matter (DOM) and heavy metals have been widely studied, and the differences in DOM properties have a great impact on the capacity of DOM-metals binding. In this study, the samples were collected from the upper lake and lower lake in Nansi Lake, respectively. According to the ratio of the fluorescence intensity of component to the total fluorescence intensity (%Fmax) in the two areas, obvious differences were found in the properties of DOM. The content of humic-like substances showed a decreasing trend from the north to south in Nansi Lake. On this basis, samples from north and south ends of Nansi Lake were selected for fluorescence titration. All components were quenched with the increasing of Cu2+ addition. Combining the results of Synchronous fluorescence (SF) spectra with two-dimensional correlation spectroscopy (2D-COS), fluorescent quenching near 275 nm was quicker than the changes that occurred at the wavelength that after 275 nm, which suggested that the complexation occurred firstly for protein-like components as compared with humic-like components. The modified Stern-Volmer model suggested that protein-like components had larger effective quenching constants (logKa = 3.47 ± 0.13 for component C5 in the upper lake and logKa = 3.57 ± 0.19 for component C4 in the lower lake) than humic-like components and it is not affected by the region, indicating that protein-like substances might have a higher metal binding potential than humic-like substances in Nansi Lake. The binding constants and the binding sites suggested that humic-like components also had a nonnegligible binding potential in Nansi Lake although the protein-like components revealed a stronger binding ability in fluorescence quenching.

中文翻译：

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南四湖沉积物溶解有机质空间分布及铜结合能力的多光谱研究

摘要 溶解性有机物（DOM）与重金属之间的相互作用已被广泛研究，DOM性质的差异对DOM与金属的结合能力有很大影响。本研究分别从南四湖的上湖和下湖采集样品。从两个区域的组分荧光强度与总荧光强度的比值（%Fmax）可以看出，DOM的性质存在明显差异。南四湖腐殖质类物质含量由北向南呈递减趋势。在此基础上，选取南四湖南北两端的样品进行荧光滴定。随着Cu2+添加量的增加，所有组分均被淬火。结合同步荧光 (SF) 光谱和二维相关光谱 (2D-COS) 结果，275 nm 附近的荧光猝灭比 275 nm 之后波长发生的变化更快，这表明络合首先发生在类蛋白质成分与类腐殖质成分相比。改良的 Stern-Volmer 模型表明，类蛋白质组分具有比类腐殖质组分更大的有效猝灭常数（上湖组分 C5 的 logKa = 3.47 ± 0.13，下湖组分 C4 的 logKa = 3.57 ± 0.19）和不受区域影响，说明南四湖中类蛋白质物质可能比类腐殖质物质具有更高的金属结合势。