He Yi, Men Bin, Yang Xiaofang, Li Yaxuan, Xu Hui, Wang Dongsheng
State Key Laboratory of Environmental Aquatic Chemistry, Research Centre for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China.
State Key Laboratory of Environmental Aquatic Chemistry, Research Centre for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China.
Chemosphere. 2017 Oct;184:235-243. doi: 10.1016/j.chemosphere.2017.05.177. Epub 2017 Jun 2.
Bioturbation/bioirrigation can affect the remobilization of metals from sediments. In this study, experiments were performed to examine the effect of bioturbation/bioirrigation by different organisms on cadmium (Cd), copper (Cu), zinc (Zn) and lead (Pb) releasing from the spiked sediment. The diffusive gradient in thin films technique (DGT) revealed that at the end of exposure time, the labile heavy metals concentrations in the pore water for all metal and organisms combinations except Cu and chironomid larvae were much lower than that in the control group. However, the concentrations of heavy metals detected by the DGT were virtually indistinguishable among the treatments with tubificid, chironomid larvae and loach. The correlation analysis of heavy metals with iron (Fe) and manganese (Mn) suggested that Cd, Zn and Pb were most likely bound as Fe-Mn oxidation form in the pore water, but Cu was in other forms. After 28 d of exposure, bioturbation/bioirrigation produced a significant release of particulate heavy metals into the overlying water, especially in the treatment with loach. The bioturbation/bioirrigation impact on the Pb remobilization was less than the other three heavy metals. The effects of bioturbaiton/bioirrigation on the heavy metals remobilization in the sediment were complex that with studying the heavy metals remobilization in the sediment and water interface, the biological indicators should be recommended.
生物扰动/生物灌溉会影响沉积物中金属的再迁移。在本研究中，开展了实验以考察不同生物的生物扰动/生物灌溉对添加了金属的沉积物中镉（Cd）、铜（Cu）、锌（Zn）和铅（Pb）释放的影响。薄膜扩散梯度技术（DGT）显示，在暴露时间结束时，除了铜和摇蚊幼虫的所有金属与生物组合的孔隙水中不稳定重金属浓度均远低于对照组。然而，在用颤蚓、摇蚊幼虫和泥鳅处理的组中，DGT检测到的重金属浓度实际上难以区分。重金属与铁（Fe）和锰（Mn）的相关性分析表明，镉、锌和铅在孔隙水中最有可能以铁 - 锰氧化态结合，但铜以其他形式存在。暴露28天后，生物扰动/生物灌溉导致颗粒态重金属大量释放到上覆水中，尤其是在泥鳅处理组中。生物扰动/生物灌溉对铅再迁移的影响小于其他三种重金属。生物扰动/生物灌溉对沉积物中重金属再迁移的影响很复杂，在研究沉积物和水界面的重金属再迁移时，应推荐使用生物指标。
