Reaction of carbon nanotubes with free chlorine and monochloramine disinfectants: Byproduct formation and implications for nanotube environmental fate and toxicity

理查德·L·瓦伦丁·瓦伦丁通过将纳米管用于新的处理技术或从纳米材料中释放出来，纳米管可以进入饮用水。该项目介绍了用游离氯和氯胺消毒剂对其进行化学处理。智慧的优点：越来越多的证据表明，氯基氧化剂将通过电子转移反应与碳纳米管反应，该反应还可能导致碳纳米管表面加氯(即形成C-氯键)以及与表面官能团的其他反应。然而，这些过程还没有在环境相关的条件下进行研究，这种反应的可溶性产物，特别是消毒剂副产物仍然未知。氯化引起的碳纳米管行为的变化以前没有被考虑过。研究将集中于鉴定各种功能化碳纳米管的材料特性，这些碳纳米管可以促进对氯基消毒剂的反应性。表面性质的变化和已知消毒副产物的潜在形成将被表征。调查人员还将评估这些消毒剂对碳纳米管的水稳定性和细胞毒性的影响。更广泛的成果：总的来说，这项工作的成果将提高工程师和科学家预测碳纳米管在环境中的命运和影响的能力。氯化碳纳米管的细胞毒性数据，再加上已确定的消毒剂副产品的毒性，应有助于监管机构制定合理的政策，限制碳纳米管在其生命周期中对人类和生态健康造成的风险。项目成果将有助于促进碳纳米管负责任的设计和应用，为制造商提供关于碳纳米管特性的指导方针，这些指导方针应该避免，以最大限度地减少对环境的不利影响。除了推动社会更可持续地发展和应用纳米技术外，这项工作还将产生更广泛的影响，解决环境工程本科生、研究生和专业人员对纳米技术教育的需求。作为该项目的标志性外展工作，调查人员将与爱荷华州负责饮用水供应、处理、分配、监管和财务的几个机构和组织合作，向目标受众提供有关纳米技术在提供安全和可接受的饮用水方面未来可能扮演的角色以及潜在的监管影响的重要信息。

Abstract#1233727Valentine, Richard L.Nanotubes may enter drinking water either through their use in novel treatment technologies or by release from nanomaterials. This project addresses their chemical processing by free chlorine and chloramine disinfectants. Intellectual Merit: Converging lines of evidence suggest that chlorine-based oxidants will react with CNTs via an electron transfer reaction that may also result in chlorine addition (i.e., C-Cl bond formation) to the CNT surface as well as other reactions with surface functional groups. However, these processes have not been investigated at environmentally relevant conditions, and soluble products of this reaction, especially disinfectant by-products remain unknown. Changes in CNT behavior resulting from chlorination have not previously been considered. Studies will focus on the identification of material properties of a variety of functionalized CNTs that promote reactivity toward chlorine-based disinfectants. Changes in surface properties and the potential formation of known disinfection by-products will be characterized. The investigators will also assess the impact of these disinfectants on the aqueous stability and cytotoxicity of CNTs. Broader Outcomes: Collectively, results of this work will improve the ability of engineers and scientists to predict the fate and effects of CNTs in the environment. Cytotoxicity data for chlorinated CNTs, in combination with established toxicities of identified disinfectant by-products should help regulators develop sound policy that limits the human and ecological health risks posed by CNTs during their life cycle. The project outcomes will help catalyze the responsible design and application of CNTs, providing manufacturers with guidelines about CNT properties that should be avoided so as to minimize adverse environmental impacts. In addition to moving society toward more sustainable development and applications of nanotechnology, broader impacts of this work will address the need for nanotechnology education at the undergraduate, graduate and professional level in environmental engineering. As the signature outreach effort for this project, the investigators will work with several agencies and organizations in Iowa that are responsible for drinking water supply, treatment, distribution, regulation, and finance to provide this target audience with important information about the future roles that nanotechnology may play in the delivery of safe and acceptable drinking water as well as potential regulatory implications.