Intensified, High-Rate Reductive Immobilization of Hexavalent Chromium

项目总结/摘要 六价铬或Cr（VI）是美国水资源中最广泛的污染物之一， 世界各地在1，699份当前或以前的国家优先清单中，至少有1，127份发现了Cr（VI） (NPL)美国环境保护署（EPA）已确定为最严重的 危险废物的网站在全国和最高优先目标的长期联邦清理活动。 毒理学研究发现，高浓度的Cr（VI）可导致胃癌、肾癌、 肝损伤和生殖损伤。因此，供水者的需求很大， 超级基金的管理人员，以创新技术解决Cr（VI）污染问题， 环境可持续的方式。 缺乏具有成本效益的技术来降低水中的Cr（VI）水平是由于相关的技术挑战 采用现有的物理/化学方法，包括高成本，需要处理二次废物 河流，和性能，可能容易受到进水地球化学。具体而言，需要 采用新技术，以更低的成本和更少的浪费，可靠地将Cr（VI）降低到非常低的十亿分之一水平 现有的物理或化学处理技术。 该项目旨在通过材料科学和细菌还原的新组合来解决这一需求 固定化。与传统的物理或化学技术相比，这种新技术不 产生危险的二次废物流。此外，所提出的技术提供了独特的氧化还原灵活性， 这使得它即使在水文地质特征可能改变时也能保持有效。这些和其他 优点有助于将所提出的技术定位为高效的非原位或原位处理方法， 实现水中低浓度的Cr（VI）。 在所提出的项目中，通过综合动力学开发了所提出技术的原型 在全基因组转录研究支持的各种操作条件下的研究。除了 开发处理系统的最佳参数，该项目还将提供独特的见解， 用于实现Cr（VI）的还原固定的生理学。复合材料的发展， 部署高密度的靶向培养物以迭代方式进行以最终选择一种复合物 在连续流反应器研究中使用合成和实际受污染的地下水进行评估。 该项目的成果将是一种新技术的概念验证， 和成本效益高的Cr（VI）治疗。因此，该项目具有重大的承诺，提供一个关键的 保护和修复饮用水供应免受铬污染的必要工具，因此 促进公共安全和环境健康。

Project Summary / Abstract Hexavalent chromium, or Cr(VI), is among the most widespread contaminants in water resources in the U.S. and around the world. Cr(VI) has been found in at least 1,127 of the 1,699 current or former National Priority List (NPL) sites, which have been identified by the U.S. Environmental Protection Agency (EPA) as the most serious hazardous waste sites in the nation and are the highest priority targets for long-term federal cleanup activities. Toxicological research has found that high concentrations of Cr(VI) can contribute to stomach cancers, kidney and liver damage, and reproductive harm. As a result, there is significant demand among water providers and managers of Superfund sites for innovative technologies to address Cr(VI) contamination in a cost-effective and environmentally sustainable manner. The lack of cost-effective technologies to reduce Cr(VI) levels in water are due to technical challenges associated with existing physical/chemical approaches, including high cost, the need for disposal of secondary waste streams, and performance that can be vulnerable to influent water geochemistry. Specifically, there is a need for new technologies to reliably reduce Cr(VI) to very low parts-per-billion levels with lower costs and less waste than existing physical or chemical treatment technologies. This project seeks to address this need through a novel combination of materials science and bacterial reductive immobilization. In contrast to conventional physical or chemical technologies, this new technology does not produce a hazardous secondary waste stream. Moreover, the proposed technology offers unique redox flexibility, which allows it to remain effective even while hydrogeological characteristics may change. These and other advantages help position the proposed technology as a highly effective ex-situ or in-situ treatment approach to achieve low concentrations of Cr(VI) in water. In the proposed project, a prototype of the proposed technology is developed through comprehensive kinetic studies under various operating conditions supported by whole-genome transcriptional studies. In addition to developing optimum parameters for the treatment system, the project will also provide insights into the unique physiology employed to achieve reductive immobilization of Cr(VI). Development of material composites to deploy a high density of the targeted culture proceeds in an iterative manner to ultimately select one composite to evaluate in a continuous-flow reactor study using both synthetic and actual contaminated groundwater. The outcome of this project will be the proof-of-concept of a new technology for efficient, environmentally friendly, and cost-effective Cr(VI) treatment. As a result, this project holds significant promise to provide a critically necessary tool for protecting and remediating drinking water supplies from chromium contamination, thus promoting public safety and environmental health.