Activated Carbon as a Multifunctional Amendment to Treat PCBs and Mercury

描述（由申请人提供）： 该项目的目标是开发活性炭（AC）改良剂作为一种多功能原位沉积物修复技术，以降低受污染沉积物场地汞（Hg）和多氯联苯（PCB）的生物利用度。活性炭颗粒将浸渍纳米级零价铁 (nZVI)，以诱导汞还原和封存，以及 PCB 脱氯。这项创新技术的成功应用可以显着降低许多危险废物场的汞和多氯联苯对人类健康的风险，同时最大限度地减少对敏感栖息地的负面影响。该项目将通过光谱、物理化学和生物测试的结合来实现其主要目标。最先进的显微光谱学将用于了解颗粒尺度上与活性炭结合的污染物。物理化学测试将探讨汞和多氯联苯在活性炭颗粒中的分配情况，并深入了解封存和脱氯率，包括从机理上了解 nZVI 在这些过程中的作用。最后，对相关蛤类物种的生物测试将证明 AC 改良剂在降低沉积物大型无脊椎动物的汞和 PCB 生物利用度方面的有效性。这些测试将使用来自 Stege Marsh（加利福尼亚州旧金山湾）的沉积物，这是一个受到汞和多氯联苯污染的有毒“热点”。使用 (nZVI-) AC 进行原位处理可以保护敏感栖息地和濒临灭绝的物种，例如加州 Stege Marsh 的拍板铁路。汞和多氯联苯污染共同造成了美国目前生效的绝大多数鱼类消费建议。此外，由于汞和多氯联苯污染场地的公众使用受到限制，因为这些经常同时出现的污染物会带来人类健康风险。这项研究将 AC 修正作为一种补救策略，通过 (1) 降低进入食物链的汞和多氯联苯的水平，以及 (2) 减少当地环境中汞和多氯联苯的可用性，从而降低这两类人类健康风险。

DESCRIPTION (provided by applicant): The goal of this project is to develop activated carbon (AC) amendment as a multifunctional, in-situ sediment remediation technique to reduce the bioavailability of both mercury (Hg) and polychlorinated biphenyls (PCBs) at contaminated sediment sites. Activated carbon particles will be impregnated with nanoscale zero-valent iron (nZVI) to induce Hg reduction and sequestration, and PCB dechlorination. Successful application of this innovative technology may significantly reduce the human health risks posed by Hg and PCBs at many hazardous waste sites, while minimizing negative impact to sensitive habitats. The project will accomplish its main goal through a combination of spectroscopic, physicochemical, and biological tests. State-of-the-art microspectroscopy will be used to understand contaminant binding to AC at the particle scale. Physicochemical tests will probe the partitioning of Hg and PCBs to AC particles, and provide insight into sequestration and dechlorination rates, including mechanistic understanding of the role of nZVI on these processes. Finally, biological tests with a relevant clam species will document the effectiveness of AC amendment in reducing Hg and PCB bioavailability to sediment-dwelling macro- invertebrates. Sediment from Stege Marsh (San Francisco Bay, CA), a toxic "hot spot" contaminated with both Hg and PCBs, will be used in these tests. In-situ treatment with (nZVI-) AC may protect sensitive habitats and endangered species, such as the California clapper rail in the case of Stege Marsh. Combined, Hg and PCB contamination are responsible for the vast majority of fish consumption advisories currently in effect in the US. In addition, public use of Hg- and PCB-contaminated sites is limited due to human health risks associated with these often co-occurring contaminants. This research advances AC amendment as a remediation strategy that will lower both types of human health risks by (1) reducing the level of Hg and PCBs entering the food chain, and (2) decreasing the availability of Hg and PCBs to the local environment.