Copper Sediment Toxicity and Partitioning during Oxidation in a Flow-Through Flume.
Copper Sediment Toxicity and Partitioning during Oxidation in a Flow-Through Flume.
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DOI：
10.1021/acs.est.5b00147
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发表时间：
2015-05
影响因子：
11.4
通讯作者：
D. Costello;C. R. Hammerschmidt;G. A. Burton
中科院分区：
文献类型：
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作者：
D. Costello;C. R. Hammerschmidt;G. A. Burton
沉积物中过渡金属的生物有效性往往取决于沉积物中的氧化还原条件。我们探索了缺氧铜改良沉积物的物理化学和毒性如何随着它们的老化而变化（即，自然氧化）在流通水槽中。我们修正了两个沉积物（道和Ocoee）与铜，培养的沉积物在一个流通水槽，并测量沉积物的物理化学和毒性超过213天。随着沉积物的老化，氧气渗透到更深的沉积物，铁氧化物的相对丰度增加，在表层和深层沉积物，和酸挥发性硫化物的浓度下降，在Ocoee表层沉积物。沉积物中Cu的总库在老化过程中没有变化，但孔隙水Cu，结合到无定形铁氧化物的Cu减少，而与结晶铁氧化物的Cu增加。的剂量反应的表底端足类Hyalella azteca沉积物总铜随时间的推移而变化，与旧的沉积物比新鲜加标沉积物的毒性较小。我们观察到孔隙水Cu和H之间存在很强的剂量-反应关系。在所有取样期内，在低于美国环境保护局建立的间隙水标准的浓度下，观察到阿兹台克生长，相对生长率出现可测量的下降。此外，固相生物利用度模型的基础上AVS和有机碳是过度保护和预测老化沉积物中的毒性差。我们建议，沉积物质量标准的铜是最好的建立从测量孔隙水中的铜，而不是估计生物可利用的铜从各种固相配体，随时间和空间的变化。
The bioavailability of transition metals in sediments often depends on redox conditions in the sediment. We explored how the physicochemistry and toxicity of anoxic Cu-amended sediments changed as they aged (i.e., naturally oxidized) in a flow-through flume. We amended two sediments (Dow and Ocoee) with Cu, incubated the sediments in a flow-through flume, and measured sediment physicochemistry and toxicity over 213 days. As sediments aged, oxygen penetrated sediment to a greater depth, the relative abundance of Fe oxides increased in surface and deep sediments, and the concentration of acid volatile sulfide declined in Ocoee surface sediments. The total pool of Cu in sediments did not change during aging, but porewater Cu, and Cu bound to amorphous Fe oxides decreased while Cu associated with crystalline Fe oxides increased. The dose-response of the epibenthic amphipod Hyalella azteca to sediment total Cu changed over time, with older sediments being less toxic than freshly spiked sediments. We observed a strong dose-response relationship between porewater Cu and H. azteca growth across all sampling periods, and measurable declines in relative growth rates were observed at concentrations below interstitial water criteria established by the U.S. EPA. Further, solid-phase bioavailability models based on AVS and organic carbon were overprotective and poorly predicted toxicity in aged sediments. We suggest that sediment quality criteria for Cu is best established from measurement of Cu in pore water rather than estimating bioavailable Cu from the various solid-phase ligands, which vary temporally and spatially.