Intensified, High-Rate Reductive Immobilization of Hexavalent Chromium

项目摘要/摘要 六价铬，或称六价铬，在美国和世界各地的水资源中是一种非常普遍的污染物。 研究发现，高浓度的铬(VI)可能会致癌，并对公众健康构成危险。AS 因此，供水供应商和超级基金网站对创新技术的需求很大，以 以具有成本效益和环境可持续的方式减少水资源中的六价铬浓度。 现有的铬(VI)修复技术目前带来的技术挑战包括高成本、有限 实现低百万分比(Ppb)浓度的能力，以及进水的超大影响 地球化学对系统性能的影响。具体地说，需要新的技术来可靠地减少铬(VI) 以比现有技术更低的成本和更好的性能实现更低的百万分之几(Ppb)水平。 这个拟议的第二阶段项目建立在第一阶段的成功成果的基础上，在第一阶段，一个新的生物过程 技术得到了发展。这项新技术是基于增强的生物还原固定化 哪种微生物可将特定金属中的可溶、可移动和剧毒的形式还原为氧化态 这些金属很难溶解，很容易从水中除去。在这项新技术中，特别是 选定的天然微生物被并入称为生物催化剂的专有聚合物复合材料中。这个 生物催化剂旨在保留、控制和维持选定的高度活跃的种群。 生物反应器内的微生物，作为紧凑型、高性能水处理系统的一部分。 在第一阶段支撑中，开发了除铬(VI)生物催化剂，并设计了原型生物反应器， 建造、运营。在连续流条件下，对不同进水浓度的去除 持续表现出铬(VI)，包括99%以上的去除水平低于1μg/L，这 远低于五(5)μg/L的目标浓度。 对复合污染物污染地下水进行了技术经济分析。 在第二阶段，这项新技术将进一步优化，然后扩大规模，在受污染的 地点。第二阶段项目旨在进一步确定这一新的性能和业务参数 技术此外，拟议的项目通过以下方式将新技术定位为立即实施 记录技术的长期运行，进行压力测试和恢复研究，以及 评估详细的维护、成本和运行参数。 这项新技术解决了一个关键需求：可靠地处理无法去除的铬(VI) 有效利用现有技术。这个项目的成功极有希望成为一个商业项目 水管理人员和供应商解决铬(VI)污染、改善水环境的首选技术 安全，并促进美国和世界各地数千个社区的公共健康。

PROJECT SUMMARY / ABSTRACT Hexavalent chromium, or Cr(VI), is a highly prevalent contaminant in water resources in the U.S. and worldwide. Research has found that high concentrations of Cr(VI) can be carcinogenic and dangerous for public health. As a result, there is significant demand among water providers and Superfund sites for innovative technologies to reduce Cr(VI) concentrations in water resources in a cost-effective and environmentally sustainable manner. Current technical challenges posed by existing technologies for Cr(VI) remediation include high costs, limited capabilities to achieve low parts-per-billion (ppb) concentrations, and the outsized effects of influent water geochemistry on system performance. Specifically, there is a need for new technologies to reliably reduce Cr(VI) to low parts-per-billion (ppb) levels with lower costs and better performance than existing technologies. This proposed Phase II project builds on successful outcomes from Phase I in which a new biological process technology was developed. The new technology is based on enhanced biological reductive immobilization in which microorganisms reduce soluble, mobile, and highly toxic forms of specific metals to oxidation states at which the metals are very poorly soluble and easily removed from water. In this new technology, specifically chosen natural microorganisms are incorporated inside proprietary polymer composites called biocatalysts. The biocatalysts are designed to retain, control, and maintain a highly active population of the chosen microorganisms inside a bioreactor as part of a compact, high-performance water treatment system. In Phase I support, the Cr(VI)-removal biocatalysts were developed, and a prototype bioreactor was designed, built, and operated. Under continuous flow conditions, the removal of various influent concentrations of Cr(VI) was consistently demonstrated, including more than 99% removal to levels below 1 μg/L, which is well below the target concentration of five (5) μg/L. The technology was validated using actual contaminated groundwater with co-contaminants and a technoeconomic analysis was conducted. In Phase II, this new technology is further optimized and then scaled-up for demonstration at a contaminated site. The Phase II project seeks to further establishes the performance and operational parameters for this new technology. In addition, the proposed project positions the new technology for immediate implementation through documenting the technology’s long-term operation, conducting stress testing and recovery studies, and assessing detailed maintenance, cost and operation parameters. This new technology addresses a critical need: the reliable treatment of Cr(VI) that cannot be removed cost- effectively using existing technologies. This project’s success holds significant promise to become a commercial technology-of-choice for water managers and providers to address Cr(VI) contamination, enhance water security, and promote public health for thousands of communities in the U.S. and around the world.