Fate, reactivity and environmental impact of using iron nanoparticles for site clean-up

根据NERC的水主题，拟议的项目旨在确定部署纳米级铁颗粒(INP)清理英国各地受污染的场地和地下水的命运、反应性和环境风险。该项目由URS/Scott Wilson支持，DEFRA(Helinor Johnston博士)和CL：AIRE(John Henstock博士)提供咨询意见。问题是：越来越多地开发和使用工程纳米材料，有可能通过在不同行业开发的许多产品中开发这些材料，为社会带来巨大利益。纳米材料的一些应用具有提供环境效益的潜力，特别令人感兴趣的是使用纳米级零价铁颗粒(INPS)来就地清理受污染的土地和地下水。理论和实践证据表明，与传统方法相比，这些INP可用于快速修复受污染的场地，成本大大降低。最重要的是，它们还适用于各种危险化学品，包括多氯联苯、重金属，甚至放射性核素。到目前为止，英国政府对故意将纳米材料释放到环境中采取了预防措施，因此，英国环境署目前不允许使用INP补救技术。2010年7月，DEFRA委托进行了一项研究(CB0440)，以评估与故意向环境中释放INP相关的假设或已知有害影响是否超过了使用INP进行场地清理可能实现的好处。虽然这项研究尚未完成，但布里斯托尔研究小组最近提供的一项详细审查强调，注入地下的INP的真实地球化学命运、它们清除污染物的真正效率以及它们可能对环境产生的影响程度，仍有许多未知之处。解决方案：通过与学术界和产业界合作，目前的项目建议弥合我们目前理解中的差距，并提供与环境中INP的生命周期有关的宝贵的现场数据。该项目将建立在布里斯托尔界面分析中心(IAC)和URS/Scott Wilson之间的现有联系之上，IAC是英国在INPS研究方面拥有最强大记录的组织，URS/Scott Wilson是一家国际知名的岩土工程和地球环境工程咨询公司。在项目期间，学生将使用不同大小和类型的INP(湿成型、干成型、退火、表面活性剂涂层)进行实验室和现场调查，以评估它们在复杂地球化学的天然水域中修复污染物的相对性能。该项目还将寻求更好地了解注入孔隙水系统的INP的具体基本生命周期方面，特别是控制运输、转化、污染物-INP的反应性和微生物影响的因素。对于项目有特殊价值的学生，URS/Scott Wilson将提供访问英国和/或海外受污染地点的途径，在这些地点，学生将在案例主管的监督下，参与使用INP的补救项目的规划、部署和监测。在英国，学生还将有机会接触到位于诺丁汉URS/Scott Wilson实验室的50立方米专业水文地球化学测试室，在那里将对使用INP的地下水修复系统进行原型和优化。据认为，目前的学员将由DEFRA和CL：AIRE提供建议，将产生数据和实用知识，有助于形成未来的英国立法和行业最佳做法，在现场清理中使用INP。

Targeted under NERC's Water theme, the proposed project is aimed at determining the fate, reactivity and environmental risk of deploying nanoscale iron particles (INP) for the cleanup of polluted sites and groundwaters around the UK. The project is CASE supported by URS/Scott Wilson with advisory input from DEFRA (Dr Helinor Johnston) and CL:AIRE (Dr John Henstock). The Problem: The increased development and use of engineered nanomaterials has the potential to offer great benefits to society through their exploitation within numerous products developed by diverse industries. Some applications of nanomaterials have the potential to afford environmental benefits and of particular interest is the use of nanoscale particles of zerovalent iron (INPs) for the in situ cleanup of contaminated land and groundwater. Theoretical and practical evidence suggests that these INPs can be used to rapidly remediate contaminated sites at a significantly reduced cost relative to conventional methods. Most significantly they are also applicable for a wide range of hazardous chemicals, including polychlorinated biphenyls (PCBs); heavy metals and even radionuclides. To date the UK government has adopted a precautionary approach to the deliberate release of nanomaterials into the environment and consequently the use of INP remediation technology is not currently permitted by the UK Environment Agency. In July 2010 DEFRA commissioned a study (CB0440) to evaluate whether the hypothesised or known detrimental effects associated with the intentional release of INPs into the environment, outweigh the benefits that may be realised by using INP for site cleanup. Whilst this study has not yet been completed, a recent detailed review provided by the Bristol group has highlighted that much is still unknown about the true geochemical fate of INP injected into the subsurface, their true efficiency for cleanup of pollutants and the level of impact they may have on the environment. The Solution: By partnering academia with industry, the current project proposes to bridge the gaps in our current understanding and provide valuable site-derived data relating to the lifecycle of INPs in the environment. The project will build upon existing links between the Bristol Interface Analysis Centre (IAC), a group with the strongest UK track record for INPs research, and URS/Scott Wilson, an internationally renowned geotechnical and geoenvironmental engineering consultancy. Over the period of the project, the student will perform both laboratory and field-based investigations using INP of different sizes and types (wet-formed, dry-formed, annealed, surfactant coated) to evaluate their relative performance for contaminant remediation in natural waters of complex geochemistry. The project will also seek to better understand specific fundamental lifecycle aspects of INP injected into pore-water systems, specifically the factors that control transport, transformation, contaminant-INP reactivity and microbial impact. Of specific value to the project, URS/Scott Wilson will provide access to contaminated sites within the UK and/or overseas where the student, under supervision of the CASE supervisor, will participate in the planning, deployment and monitoring of a remediation project using INP. In the UK the student will also have access to a specialist 50m3 hydrogeochemical test cell located at URS/Scott Wilson's laboratories in Nottingham, where groundwater remediation systems using INP's will be prototyped and optimised. It is considered that the current studentship, which will be advised by both DEFRA and CL:AIRE, will produce data and practical knowledge that will help to shape future UK legislation and industry best practice for the use of INP in site clean-up.