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碳(AC)修改剂，作为一种多功能的就地沉积物修复技术，以降低受污染沉积物中汞(Hg)和多氯联苯(PCbs)的生物可利用性。活性碳颗粒将被纳米级零价铁(NZVI)浸渍，以诱导汞还原和隔离以及多氯联苯的脱氯。这项创新技术的成功应用可能会大大减少汞和多氯联苯在许多危险废物地点对人类健康造成的风险，同时最大限度地减少对敏感生境的负面影响。该项目将通过光谱、物理化学和生物测试的组合来实现其主要目标。最先进的显微光谱学将被用来在颗粒尺度上了解污染物与AC的结合。物理化学测试将探索汞和多氯联苯在AC颗粒中的分配，并提供对隔离和脱氯速率的洞察，包括从机理上理解nZVI在这些过程中的作用。最后，对相关的文蛤物种进行的生物测试将证明AC改良剂在降低汞和多氯联苯对沉积物栖息的大型无脊椎动物的生物有效性方面的有效性。来自加利福尼亚州旧金山湾的Stege Marsh的沉积物将用于这些测试，Stege Marsh是一个同时受到汞和多氯联苯污染的有毒“热点”。用(nZVI-)AC进行原位处理可能会保护敏感的栖息地和濒危物种，例如Stege Marsh的加利福尼亚克拉珀铁轨。总而言之，汞和多氯联苯污染是美国目前生效的绝大多数鱼类消费建议的原因。此外，汞和多氯联苯污染场地的公众使用受到限制，因为与这些经常共存的污染物有关的人类健康风险。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水平，以及(2)减少汞和多氯联苯对当地环境的可获得性，从而降低这两种类型的人类健康风险。

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.