| 洪泽湖溶解态有机质与重金属汞的结合特性 |
| 摘要点击 1721 全文点击 598 投稿时间：2021-08-17 修订日期：2021-10-01 |
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| 中文关键词 溶解态有机质(DOM) 汞(Hg) 荧光光谱 荧光淬灭 洪泽湖 |
| 英文关键词 dissolved organic matter (DOM) mercury (Hg) fluorescence spectroscopy fluorescence quenching Hongze Lake |
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| 中文摘要 |
| 水体中溶解态有机质（DOM）能够与重金属络合形成复合化合物，进而影响水环境中重金属的迁移转化、生物可利用性和毒性.通过荧光光谱结合不同的光谱分析方法研究了洪泽湖不同季节水体DOM与重金属汞（Hg）的结合特性.结果表明，春季DOM以类蛋白质为主，秋季则以类腐殖质为主，洪泽湖秋、冬季蓄水导致DOM性质存在显著差异.同步荧光光谱结合二维相关光谱分析结果表明，洪泽湖春季DOM与Hg （Ⅱ）的结合强度依次为：360~425 nm>290 nm>300~350 nm，秋季DOM与Hg （Ⅱ）的结合强度依次为：290 nm>315~355 nm>365~380 nm>380~465 nm.三维荧光光谱和荧光淬灭实验表明，洪泽湖水体DOM的5种荧光组分均与Hg （Ⅱ）有不同程度地络合.Ryan-Weber模型拟合结果进一步表明，春季DOM类腐殖质组分与Hg （Ⅱ）结合能力强于类蛋白质，秋季则是类蛋白质组分的结合能力强于类腐殖质.总体而言，洪泽湖秋、冬季蓄水能够显著改变DOM的性质，从而影响DOM与重金属Hg （Ⅱ）的结合特性，可能会增强洪泽湖水体中Hg的生物可利用性和毒性. |
| 英文摘要 |
| Dissolved organic matter (DOM) can form complex compounds with heavy metals and then affect the transport, transformation, bioavailability, and toxicity of heavy metals in aquatic environments. Here, fluorescence spectroscopy combined with various spectral analysis methods were conducted to study the binding affinity between heavy metal Hg and seasonal dissolved organic matter in Hongze Lake. DOM was dominated by protein-like substances in spring, whereas DOM in autumn was dominated by humic-like substances. These results indicated that lake impoundment during autumn and winter resulted in significant variations in DOM compositions in Hongze Lake. Two-dimensional correlation spectroscopy analysis of synchronous fluorescence spectra revealed that the binding sequence to Hg(Ⅱ) was 360-425 nm>290 nm>300-350 nm for spring DOM and 290 nm>315-355 nm>365-380 nm>380-465 nm for autumn DOM. Fluorescence quenching characteristics showed a relatively different trend for five fluorescent components. The results of the Ryan-Weber model further indicated that the binding affinity with Hg(Ⅱ) for spring humic-like components was higher than that for protein-like components. However, the opposite binding affinity between humic- and protein-like components and Hg(Ⅱ) was observed for autumn DOM. In general, impoundment could significantly alter the DOM composition and the binding affinity between DOM and heavy metal Hg and may eventually increase the bioavailability and toxicity of Hg in Hongze Lake. |
