Measurement of heavy metal speciation over redox gradients in natural water-sediment interfaces and implications for uptake by benthic organisms.
Measurement of heavy metal speciation over redox gradients in natural water-sediment interfaces and implications for uptake by benthic organisms.
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DOI：
10.1021/es0200701
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发表时间：
2002-12
影响因子：
11.4
通讯作者：
J. Vink
中科院分区：
文献类型：
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作者：
J. Vink
沉积物或动物孵化实验（SOFIE）是一种实验研究工具，用于分析天然原状沉积物或水-沉积物界面孔隙沃茨中重金属的浓度和化学形态随时间的变化，同时对沉积物生物进行暴露试验。因此，化学物种的浓度与生物区系的积累直接相关。结果表明，氧化还原敏感的金属和营养物质的离散梯度发生在非常小的间隔。这些梯度不同于游离金属离子的活性梯度。形态影响沉积物生物对金属的吸收，而沉积物生物又对金属形态产生重大影响。由于每种金属的反应动力学不同，生物体从水相中摄取金属可能受到阻碍（例如，Cu，Zn）或促进的（例如，Ni，As）。在吸收和消除模型中纳入了随时间变化的金属暴露浓度。水体中的镉，铜，镍，锌的水生寡毛类Limnodrilus的浓度可以最好地描述随时间变化的自由离子浓度在上覆水。体浓度的As和Pb的沉积物孔隙水浓度最好的描述。它的结论是SOFIE提供了必要的实验工具，以支持，在一个机械的方式，污染物的环境风险评估。
The sediment or fauna incubation experiment (SOFIE) is an experimental research tool that was developed to analyze concentrations and chemical speciation of heavy metals in pore waters of natural, undisturbed sediments or water-sediment interfaces over time, while simultaneously conducting exposure tests with sediment-dwelling organisms. In this way, concentrations of chemical species are directly linked to accumulation by biota. It is shown that discrete gradients of redox-sensitive metals and nutrients occur over very small intervals. These gradients differ from those of free metal ion activities. Speciation affects the uptake of metals by sediment-dwelling organisms, which, in their turn, have a significant effect on metal speciation. With reaction kinetics that differ per metal, uptake of metals by organisms from the water phase may be hindered (e.g., Cu, Zn) or promoted (e.g., Ni, As). Time-varying exposure concentrations of metals were incorporated in uptake and elimination models. Body concentrations of Cd, Cu, Ni, and Zn in the aquatic oligochaete Limnodrilus could best be described by the time-varying free ion concentration in the overlying water. Body concentrations of As and Pb were best described by sediment pore water concentrations. It is concluded that SOFIE provides the necessary experimental tool to support, in a mechanistic way, environmental risk assessments of contaminants.