Activated Carbon as a Multifunctional Amendment to Treat PCBs and Mercury

描述（由申请人提供）： 本项目的目标是开发活性炭（AC）修正剂，作为一种多功能的原位沉积物修复技术，以降低受污染沉积物中汞（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），以诱导汞的减少和封存，以及PCB脱氯。成功应用这一创新技术，可以大大减少许多危险废物场汞和多氯联苯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、物理化学和生物学测试的结合来实现其主要目标。国家的最先进的显微光谱学将被用来了解污染物结合到AC在颗粒尺度。物理化学测试将探测汞和多氯联苯对活性炭颗粒的分配，并提供对螯合和脱氯率的深入了解，包括对nZVI在这些过程中的作用的机械理解。最后，对相关蛤类进行的生物试验将证明活性炭改良剂在降低沉积物大型无脊椎动物对汞和多氯联苯的生物利用率方面的有效性。这些测试将使用来自斯泰格沼泽（加利福尼亚州旧金山弗朗西斯科湾）的沉积物，这是一个被汞和多氯联苯污染的有毒“热点”。原位处理（nZVI-）AC可以保护敏感的栖息地和濒危物种，如斯泰格沼泽的加州的美洲秧鸡。汞和多氯联苯污染是美国目前实施的绝大多数鱼类消费禁令的原因。此外，汞和多氯联苯污染场地的公共使用受到限制，因为这些污染物往往同时存在，对人类健康构成风险。本研究将活性炭改良作为一种补救策略，通过（1）降低进入食物链的汞和多氯联苯的水平，（2）减少汞和多氯联苯在当地环境中的可用性，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.