Intensified, High-Rate Reductive Immobilization of Hexavalent Chromium

项目总结/摘要 六价铬或Cr（VI）是美国和世界范围内水资源中非常普遍的污染物。 研究发现，高浓度的Cr（VI）可能致癌，并对公众健康造成危险。作为 因此，供水商和超级基金站点对创新技术的需求很大， 以具有成本效益和环境可持续的方式降低水资源中的Cr（VI）浓度。 现有的Cr（VI）修复技术所带来的技术挑战包括成本高、有限的环境污染、环境污染和环境污染。 实现低十亿分之一（ppb）浓度的能力，以及进水的巨大影响 地球化学对系统性能的影响具体而言，需要新技术来可靠地减少Cr（VI） 降低到十亿分之一（ppb）水平，成本更低，性能比现有技术更好。 该拟议的第二阶段项目建立在第一阶段的成功成果之上，在第一阶段中， 技术被开发出来。这项新技术是基于增强生物还原固定化， 所述微生物将可溶的、移动的和高毒性形式的特定金属还原为氧化态， 其中金属的溶解性非常差，并且容易从水中除去。在这项新技术中， 所选择的天然微生物被结合到称为生物催化剂的专有聚合物复合材料中。的 生物催化剂被设计为保留、控制和维持所选生物的高度活性群体。 作为紧凑型高性能水处理系统的一部分，生物反应器内的微生物可被高效降解。 在第一阶段的支持下，开发了Cr（VI）去除生物催化剂，并设计了原型生物反应器， 建造和运营。在连续流条件下， Cr（VI）的去除率始终保持在99%以上，达到1 μg/L以下， 远低于目标浓度5 μg/L。该技术得到了验证，使用实际 对受共污染物污染的地下水进行了技术经济分析。 在第二阶段，这项新技术得到进一步优化，然后扩大规模，在受污染的 绝佳的价钱第二阶段项目旨在进一步确定这一新技术的性能和操作参数。 技术.此外，拟议的项目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， 评估详细的维护、成本和操作参数。 这项新技术解决了一个关键的需求：可靠地处理无法去除的Cr（VI）， 有效利用现有技术。这个项目的成功具有重要的承诺，成为商业 水管理者和供应商解决Cr（VI）污染、提高水资源利用率和减少污染物排放的首选技术 安全，并促进美国和世界各地数千个社区的公共卫生。

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.