Redox-Active Fe-Bearing Clay-Coated Sand for Groundwater Remediation

没有一个工业化国家或发展中国家充分保护其含水层免受家庭、农业和工业污染物的侵害，世界许多地区的地下水污染处于历史最高水平。在英国，据估计，用于公共供应的近一半地下水的质量受到影响，导致资本和运营成本高昂，并增加了消费者的水费。这个问题的规模和紧迫性在很大程度上得到了认可，英国和整个欧盟的管理当局正在不断修改他们的污染控制或减排方法。欧共体水框架指令现在要求到2015年所有成员国的地表、沿海和地下沃茨达到“良好状态”。在仅有9年时间的情况下，开发和实施具有成本效益和可持续的水修复技术的举措是至关重要的。拟议项目旨在开发和展示一种新型反应材料的效率和耐久性，该材料将用于设计用于修复受污染地下水的可渗透反应屏障。这项拟议中的研究是有史以来第一次，它将利用某些聚合物在有效地将粘土颗粒结合到砂粒表面的独特能力，并将利用现已被公认的还原含铁蒙脱石在促进各种有机化合物降解方面的能力。或补救各种无机和有机污染物，包括硝基芳烃和氯化化合物，因此可以自给自足地处理某些复杂的地下水羽流。与PRB中常用的其他反应性材料（包括零价铁）相比，它们也有望成为更可持续的，可能是更具成本效益的替代品。拟议项目将在2年内完成，将涉及模拟现场条件的实验室规模实验，并将使用最先进的设施和多学科方法进行，将粘土科学，岩石/土壤力学，有机地球化学该项目的前16个月将允许确定适当的程序，使粘土涂层砂所需的渗透性用于PRB，并将有助于评估其稳定性和水力特性作为pH值变化和铁还原的函数。最后8个月将允许使用硝基苯作为模型污染物在实验室模拟PRB条件下评估多孔材料的修复性能。粘土涂层砂的估计成本效益将与文献中常用的PRBs.The项目的结果是至关重要的，以告知科学界，决策者，管理人员和利益相关者的新的粘土基活性材料的相关性的其他活性材料的数据进行比较。将获得的基本理解将用于吸引英国的工业合作伙伴，并倡导部署一个中试规模的PRB技术，用于使用具有足够渗透性的含铁粘土涂层砂修复受污染的地下水。

None of the industrialized or developing countries has adequately protected its aquifers against domestic, agricultural and industrial contaminants and groundwater pollution is at an all time high in many parts of the world. In the UK, the quality of almost half of the groundwater used for public supply is estimated to be compromised, resulting in high capital and operating costs and increasing water charges for the consumer. The scale and urgency of the problem is largely recognised and managing authorities in the UK and across the EU are continuously revising their approach to pollution control or abatement. The EC Water Framework Directive now requires that surface, coastal and underground waters meet 'good status' within all the member states by 2015. With only 9 years to go, initiatives to develop and implement cost-effective and sustainable water remediation technologies are crucially needed.The proposed project aims to develop and demonstrate the efficiency and durability of a novel reactive material to be used in the design of permeable reactive barriers for the remediation of contaminated groundwater. The proposed research is cutting-edge in that, for the first time ever, it will take advantage of the unique ability of some polymers in efficiently binding clay particles to the surface of sand grains and will exploit the now well recognised ability of reduced Fe-bearing smectites in promoting the degradation of various organic compounds.The new Fe-bearing clay-coated sands are expected to efficiently immobilize and/or remediate a wide range of inorganic and organic contaminants, including nitroaromatics and chlorinated compounds, and may therefore be self-sufficient for the treatment of certain complex groundwater plumes. They are also expected to be a more sustainable and possibly a more cost-effective alternative than other reactive materials commonly used in PRBs, including zero valent iron.The proposed project will be completed in 2 years and will involve bench-scale experiments simulating field-conditions and will be conducted using state-of-the-art facilities and a multi-disciplinary approach, associating clay science, rock/soil mechanics, and organic geochemistry. The first 16 months of the project will allow identifying adequate procedures for making clay-coated sands of required permeability for use in PRBs and will help evaluate their stability and hydraulic properties as a function of pH changes and iron-reduction. The last 8 months will allow assessing the remediation performance of the porous materials under laboratory simulated PRB conditions using nitrobenzene as model contaminant. The estimated cost-effectiveness of the clay-coated sands will be compared with data available in the literature for other reactive materials commonly used in PRBs.The results of the project are crucially needed to inform the scientific community, policymakers, managers and stakeholders on the relevance of the new clay-based reactive material. The fundamental understanding to be gained will be used to attract industrial partners in the UK and advocate the deployment of a pilot-scale PRB technology for the remediation of contaminated groundwater using a Fe-bearing clay-coated sand of adequate permeability.