University of Chinese Academy of Science, Beijing 100049, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Science, Nanjing 210008, China.
University of Chinese Academy of Science, Beijing 100049, China; Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
Sci Total Environ. 2022 Sep 1;837:155438. doi: 10.1016/j.scitotenv.2022.155438. Epub 2022 Apr 27.
The toxicity of heavy metals in sediments is inseparable from their forms in the environment. Traditional sediment toxicity assessment systems, such as total metals, dissolved metals in pore water, metals extracted by the Community Bureau of Reference procedure, and acid volatile sulphide (AVS)-simultaneously extracted metal (SEM), have their own limitations. This study revealed the horizontal and vertical distribution characteristics of AVS and SEM in Lake Chaohu and three typical groups of two-dimensional profiles of diffusive gradients in thin-film (DGT)-labile S(-II) were obtained at representative sampling sites. There was a positive correlation between DGT-labile S(-II) and AVS due to sulphate-reducing bacteria and a negative correlation due to the high sulphate reduction rate induced by high total organic carbon. Moreover, there was no correlation between DGT-labile S(-II) and AVS when bioturbation was dominant in the sediments. To realise the application of DGT measurement in toxicity assessment of heavy metals in sediment through the sandwich relationship of DGT-labile metals vs. metals speciation vs. sediment toxicity assessment, the key relationship of DGT-labile metals vs. metals speciation was explored. DGT-labile Ni showed potential to reveal this relationship.
重金属在沉积物中的毒性与其在环境中的形态密不可分。传统的沉积物毒性评估系统，如总金属、孔隙水中溶解的金属、社区参考局程序提取的金属和可酸提取的挥发硫化物（AVS）-同时提取的金属（SEM），都有其自身的局限性。本研究揭示了巢湖沉积物中 AVS 和 SEM 的水平和垂直分布特征，并在代表性采样点获得了三种典型二维二维扩散梯度薄膜（DGT）-可溶硫（-II）剖面。由于硫酸盐还原菌的作用，DGT-可溶硫（-II）与 AVS 呈正相关，而由于总有机碳含量高导致的高硫酸盐还原率则呈负相关。此外，当沉积物中生物搅动占主导地位时，DGT-可溶硫（-II）与 AVS 之间没有相关性。为了通过 DGT-可溶金属与金属形态与沉积物毒性评估的三明治关系实现 DGT 测量在沉积物中重金属毒性评估中的应用，探讨了 DGT-可溶金属与金属形态的关键关系。DGT-可溶镍显示出揭示这种关系的潜力。
