State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
Shanghai Waterway Engineering Design and Consulting Co., Ltd., Shanghai 200120, China.
Sci Total Environ. 2019 Jun 20;670:361-368. doi: 10.1016/j.scitotenv.2019.03.167. Epub 2019 Mar 13.
Zinc (Zn) contamination in lake zones dominated by algae and macrophytes in Lake Taihu was analyzed through diffusive gradient in thin films (DGT) and dialysis (HR-Peeper) methods. It was found that in both zones Zn contamination varied by season. In July and October, dissolved Zn was present in high concentrations, and in July, high concentrations of labile Zn were found in sediments. In July, reductive dissolutions of Fe/Mn oxides likely played a key role in the release of Zn, which was confirmed by both zones having the lowest percentage of the reducible fraction of Zn in July. Complexation of dissolved organic matter (DOM) with Zn may be responsible for the observed increase in the dissolved Zn concentration in October. This conclusion was supported by noting that October had the highest percentages of Zn-DOM complexes (25.3% and 34.4%) in the algae- and macrophytes-dominated zones, respectively. However, in January, low dissolved and labile Zn contents were observed in sediments in the two zones, suggesting that the decrease of Zn in sediments was caused by the adsorption of Fe/Mn oxides.
采用扩散梯度薄膜（DGT）和透析（HR-Peeper）方法分析了太湖水生植物和藻类占主导地位的湖区中锌的污染情况。结果表明，两个区域的锌污染都随季节而变化。7 月和 10 月，溶解态锌的浓度较高，而 7 月时，沉积物中发现了大量的可利用态锌。7 月时，铁/锰氧化物的还原溶解可能在锌的释放中起关键作用，这一点在两个区域的可还原态锌比例在 7 月时最低得到了证实。溶解态有机物（DOM）与锌的络合作用可能是 10 月观察到溶解态锌浓度增加的原因。这一结论得到了支持，因为在藻类和水生植物占主导地位的区域，10 月的锌-DOM 络合物比例分别高达 25.3%和 34.4%。然而，在 1 月，两个区域的沉积物中溶解态和可利用态锌含量都较低，表明沉积物中锌的减少是由于铁/锰氧化物的吸附所致。
