Chloro-Organic Degradation by Polymer Membrane Immobilized Iron-Based Particle Sy

项目总结(项目5--Bhattacharyya，Ormsbee) 由于其相对化学稳定性和无处不在的性质，氯化有机化合物，如 多氯联苯和三氯乙烯继续构成补救挑战和 人类健康风险。在许多超级基金地点，过去使用传统治疗策略的补救努力(例如， 反应障碍物、六相加热等)已经被证明是非常昂贵的，基本上是无效的。备择 策略包括将氯有机降解为无毒的还原途径和氧化途径 化合物。纳米铁基材料的发展带来了重要的前景 技术进入环境修复领域。近年来，零价纳米金属(特别是 铁)颗粒在地下水氯化溶剂修复中受到越来越多的关注。了解更多 快速和完全还原脱氯时，通常会添加第二种金属，从而生成双金属纳米颗粒。 在过去，这种方法在超级基金实际站点的使用一直受到限制，原因是担心 颗粒聚集或释放到环境中。项目5将解决有针对性的补救需求 通过开发集成的、成本效益高的技术来制定战略，其中既包括还原技术，也包括氧化技术 战略，以便能够完全修复氯化有机化合物而不产生 有毒副产品的三个具体目标是：1)创建一种多孔的、固定的普通聚合物膜 使用环境安全方法合成活性和稳定的铁基纳米颗粒的平台 防止颗粒聚集和丢失；2)将固定化纳米颗粒嵌入响应膜域 通过还原和氧化方法实现高效的多氯联苯和三氯乙烯脱氯；3)确定 是否以双金属(铁和钯)纳米颗粒还原为第一步进行多氯联苯脱矿， 然后用固定在聚合物膜结构域中的氧化铁纳米颗粒进行氧化，将消除 形成有毒的氯取代中间体，经毒性测试证实。为了实现这些目标，一个 聚合物/膜平台将在实验室规模和全规模开发，以实现环境友好 纳米结构铁合成，并将建立单独和组合的技术战略，以减少 氯有机物(部分多氯联苯和氯乙烯)的毒性。拟议的方法应解决 与使用双金属纳米颗粒相关的团聚和毒性问题，并允许 将氯化有机化合物完全分解为无毒和可生物降解的中间体。这个 该项目将包括与美国环境保护局(EPA)的国家风险合作 管理研究实验室专注于利用EPA设施进行纳米颗粒的合成和表征。 与过去一样，该项目将与州和联邦各级的不同主要利益攸关方合作，以实施 在肯塔基州最大的超级基金工厂帕迪尤卡气体扩散厂开发的技术。

PROJECT SUMMARY (Project 5 - Bhattacharyya, Ormsbee) Due to their relative chemical stability and ubiquitous nature, chlorinated organic compounds such as polychlorinated biphenyls (PCBs) and trichloroethylene (TCE) continue to pose both remediation challenges and human health risks. At many Superfund sites, past remediation efforts using traditional treatment strategies (e.g., reactive barriers, six phase heating, etc.) have proven to be highly costly and largely ineffective. Alternative strategies include both reductive and oxidative pathways for chloro-organic degradation to non-toxic compounds. The development of nanosized iron-based materials has brought important and promising techniques into the field of environmental remediation. In recent years, zero-valent nanoscale metal (especially iron) particles have attracted growing attention in groundwater remediation of chlorinated solvents. For more rapid and complete reductive dechlorination, a second metal is often added, resulting in bimetallic nanoparticles. In the past, utilization of such approaches at actual Superfund sites has been limited due to concerns about particle agglomeration or release into the environment. Project 5 will address the need for targeted remediation strategies by developing integrated, cost-effective technologies which incorporate both reductive and oxidative strategies in order to allow the complete remediation of chlorinated organic compounds without the production of toxic byproducts Three specific aims are to: 1) create a porous, common polymer membrane immobilized platform for synthesis of reactive and stable iron-based nanoparticles using environmentally safe approaches to prevent aggregation and loss of particles; 2) embed immobilized nanoparticles in responsive membrane domain to allow highly effective PCB and TCE dechlorination by both reductive and oxidative approaches; 3) determine whether PCB demineralization with reduction by bimetallic (iron and palladium) nanoparticles as a first step, followed by oxidation with iron oxide nanoparticles immobilized in polymer membrane domain, will eliminate the formation of toxic chlorine-substituted intermediates, as verified by toxicity tests. To accomplish the aims, a polymer/ membrane platform will be developed in both lab scale and full-scale for environmentally benign nanostructured iron synthesis, and individual and combined technology strategies will be established to reduce the toxicity of chloro-organics (selected PCBs and chloroethylenes). The proposed approach should address the agglomeration and toxicity concerns associated with the use of bimetallic nanoparticles and allow for the complete breakdown of chlorinated organic compounds to nontoxic and biodegradable intermediates. The project will include collaborations with the U.S. Environmental Protection Agency's (EPA's) National Risk Management Research Laboratory focused on nanoparticle synthesis and characterization using EPA facilities. As in the past, the project will work with diverse primary stakeholders at state and federal levels to implement the developed technologies at the Paducah Gaseous Diffusion Plant, Kentucky largest Superfund site.