A former mining site has been the subject of extensive remediation and restoration, with a significant focus on disconnecting mine spoils from groundwater and managing the quantity and quality of runoff. A remaining task is ensuring concentrations of zinc (Zn) in the stream outflow of a pit lake are reduced below water quality standards. The efficacy of multiple capping materials for decreasing Zn dissolution from sediments was conducted under natural and reasonable worst-case conditions (pH = 5.5). Capping materials included AquaBlok™, limestone, and limestone-bone char. Field exposures were conducted in limnocorrals that isolated overlying water columns above the sediment and capping treatments. Simultaneous in situ and ex situ toxicity tests were conducted using Daphnia magna, Hyalella azteca, and Chironomus dilutus. In situ caged organisms were protected from temperature shock (warm epilimnetic waters) by deploying within a Toxicity Assessment Container System (TACS). Organisms were exposed to surficial sediments, caps, and hypolimnetic overlying waters for 4 d. Ex situ testing was conducted in core tube mesocosms containing sediments and caps at similar temperatures (15-19 °C). Results demonstrated the usefulness of TACS deployment in stratified lake systems. There were no differences in responses between treatments involving sediment capping materials in both in situ and ex situ tests. The lack of differences was likely due to dissolved Zn in surface water being below the hardness-adjusted threshold effects levels (164 μg L-1 ). This field- and laboratory-based weight-of-evidence study provided site-specific data to support the selection of an effective remedy, with reduced uncertainty compared to laboratory and chemistry-only approaches. Environ Toxicol Chem 2019;39:240-249. © 2019 SETAC.

中文翻译：

---

沉积物封盖材料对锌通量，生物利用度和毒性的影响的实验室和基于现场的评估。

以前的采矿场一直是广泛的修复和恢复的主题，其主要重点是将矿渣从地下水中分离出来，并管理径流的数量和质量。剩下的任务是确保将坑湖的溪流中锌（Zn）的浓度降低到低于水质标准。在自然和合理的最坏情况下（pH = 5.5）进行了多种覆盖材料降低锌从沉积物中溶出的功效。封盖材料包括AquaBlok™，石灰石和石灰石骨炭。野外暴露是在稀疏层中进行的，该稀疏层隔离了沉积物上方的水柱和封盖处理。使用大型蚤（Daphnia magna），透明质酸透明质酸（Hyalella azteca）和稀释性Chironomus dilutus进行了原位和异位毒性测试。通过在毒性评估容器系统（TACS）中进行部署，可以保护原位笼养生物免受温度冲击（温暖的表皮水）。将有机物暴露于表面沉积物，水帽和低边际上覆水域4 d。异位测试是在相似温度（15-19°C）下，在包含沉积物和帽的芯管介观过程中进行的。结果表明，在分层湖泊系统中部署TACS很有用。在原位和非原位测试中，涉及沉积物覆盖材料的处理之间的响应没有差异。差异的缺乏可能是由于地表水中溶解的Zn低于硬度调整的阈值效应水平（164μgL-1）。这项基于现场和实验室的证据权重研究提供了特定地点的数据，以支持选择有效的补救措施，与仅采用实验室和化学方法相比，不确定性降低了。Environ Toxicol Chem 2019; 39：240-249。©2019 SETAC。