The release of particles of nanometre scale to the environment for the clean up of pollution is an emerging technology. At the forefront is the development of nanoscale zerovalent iron (nZVI) to clean up environments that have become polluted with chlorinated organic compounds. The nZVI works by removal of chlorine atoms from the pollutant, usually resulting in the production of a less toxic and less persistent compound. nZVI has been most commonly used for clean up of ground water, however, application to contaminated soil is now showing promise with the development of ways to deploy nZVI into the soil matrix without it sticking to the soil, or itself. Because of their dimensions, nZVI particles have the potential to interact at a scale relevant to microbes living in the soil, either directly through contact with microbial cells, or, indirectly through altering the chemical environment in which soil microbes live. It is important to assess whether nZVI has detrimental impacts on soil microbes because of the important functions the microbes carry out; these include biogeochemical cycling with resulting provision of nutrients to plants and the breakdown of organic pollutants. Thus, this proposal will test the impacts of nZVI on two important microbial groups; one involved in the decomposition of a major class of pollutants, the polychlorinated biphenyls (PCBs), and the other responsible for symbiotic improvement of plant growth and thus for enhancing and stabilising soils. The context of the study will be a two-step soil clean up scenario. The first step involves the use of nZVI to reduce the number of chlorines in the PCBs, which reduces their toxicity. The second, biological, step involves use of native soil microbes to decompose the nZVI-produced mono or dechlorinated products with subsequent planting of the soil to stabilise the site and stimulate beneficial pollutant decomposing microbes. For laboratory experiments, we will use commercially produced nZVI of different sizes and formulation. In consequence, we will address nZVI commercial applications whilst defining the environmental impact for a range of nZVI reactivities. In the course of our research we will answer the following questions: 1. Does nZVI impact on the numbers, activity and diversity of soil microbial communities responsible for the breakdown of pollutants? 2. Does nZVI impact on plant-microbe symbioses? Specifically: (i) legume symbiosis with symbiotic rhizobia bacteria responsible for formation of nitrogen-fixing nodules on plant roots; and, (ii) symbiotic arbuscular mycorrhizal fungi which form a 'fungus root' and benefit the plant host in many ways, including improvement of phosphorus nutrition. 3. Does the nZVI impact on soil microbial communities depend on the reactivity of nZVI and its environmental behaviour? We will assess the diversity of microbial communities using a nucleic-acid based fingerprinting method and measure their activity by quantifying the rate at which they decompose an added pollutant chemical. The impact on symbiosis will be determined by: (i) counting numbers of root nodules and the rate at which they fix nitrogen; and, (ii) the extent of root colonisation by arbuscular mycorrhizal fungi and plant phosphorus levels. We will manipulate nZVI reactivity by varying the size of the particles (bigger surface area = higher reactivity) and formulation (addition of a surfactant to stop them from agglomerating). We will see how the nZVI particles behave in soil by using an electron microscope. Also, we will apply to use the synchrotron 'super-microscope', a new facility in Oxfordshire, to assess its potential to look at nZVI agglomeration in an undisturbed soil situation.

The world's population likes living by the sea. Currently approximately 53% of us live on the 10% of the earth's surface that is within 200km of the coast; this is forecast to rise to 75% by 2050. This increased concentration of people in restricted areas will place greater stress on natural resources including water supplies. These resources must be used in a judicious manner if we are to live within our means. Meeting the needs for providing potable water to 75% of humanity from such a limited resource forms a major global challenge facing society in the 21st Century. Groundwater has been recognised for some time for its capacity to provide good quality water, particularity in places where other water sources have either poor quality, requiring expensive (and environmentally unfriendly) treatment technologies, or are unavailable. However, it needs to be used cautiously. Over-pumping of coastal aquifers can lead to seawater contaminating groundwater supplies, thereby destroying otherwise valuable resources. Contamination by even 1% salt water can be enough to render freshwater unfit for use. This issue is of concern in the UK, where saline intrusion (SI) can affect the quality of water used for human consumption, as well as for industrial purposes (process water and irrigation). Further afield, this matter is of pressing concern across Europe, particularly in Mediterranean countries, as well as in other water-stressed arid and semi-arid regions of the planet where use of desalinisation technologies may not be viable over the long term. The UK Water Research and Innovation Partnership has highlighted weaknesses in the UK water industry that could prevent it from maintaining its position against increasing external competition. In order to develop a 10% Global market share, worth $8.8 billion, the UK needs to invest in water research to maintain its competitive edge. The partnership has identified opportunities for developing innovative water technologies in 21 areas, where it believes that the UK can compete on the world stage. Developing these technologies requires a firm scientific underpinning. This proposal addresses developing expertise in the area of SI using accurate monitoring, prediction and control systems. Findings will underpin protocols that will increase the effectiveness of sustainable water infrastructure management through demand management tools. The proposal's multidisciplinary research team from Queen's University Belfast and Imperial College London brings together expertise in the areas of experimental hydrodynamics, process engineering, numerical simulation, computational fluid dynamics, field hydro-geology and geophysics; this is further strengthened through active involvement of the British Geological Survey. The integration of experimentation with testing and monitoring in real world environments, along with improved numerical simulation that will lead to the development of an early warning system for salt water breakthrough to provide a sustainable managed approach for water abstraction in coastal areas. Understanding the movement of seawater and freshwater within coastal aquifers, and the interactions that take place under naturally complex ground conditions, provides the key to unlocking suitable approaches for designing and maintaining effective water management systems needed to meet the ever growing demand for high quality freshwater in coastal areas. Our vision is to create a novel system capable of providing early warning of salt water intrusion within groundwater wells. This advance notification, of up to 8 days, will allow actions to be taken in advance of contamination occurring. A dynamic model, which will further help with the understanding of the transient processes that govern SI movement under real world conditions, will provide a novel practical management suite of tools for water suppliers and environmental regulators.

Construction using geosynthetics offer savings both in terms of cost and embodied carbon. However, their application is limited by poor understanding of geosynthetic soil interaction, resulting in at best over conservative designs and at worst failures resulting in uncontrolled contamination and loss of life. This fifteen month project will use digital imaging and rapid prototyping to create higher strength interaction between geosynthetics and adjacent materials, allowing steeper, higher and safer slopes to be constructed, thus facilitating sustainable construction using these materials. In barrier systems, geomembranes are typically placed, as part of multilayer systems, over low permeability clay to create a composite barrier benefiting from the low permeability of the geomembrane and attenuation properties of the clay. The geomembrane is then overlain by a geotextile or sand to project it from puncture and damage from the overlying material. This project will allow design of geomembrane surfaces for interaction with these adjacent materials. The designed interfaces will have greater peak strength and allow designers to understand and specify the characteristics of interface shear strength beyond simply the height of the surface texturing (asperity height). In practical terms it will allow higher and steeper slopes when using geomembrane barrier systems, offering improved project profitability and safer use across all applications. The upper bound interface shear strength is controlled by the material adjacent to it. For a geosynthetic-soil interface this is the strength of the soil. For a geomembrane-geotextile interface the maximum strength will be controlled by the internal bond and fibre strength of the geotextile. The role of the texturing is to transfer the stresses into the adjacent material. The "one size fits all" approach of 0.25mm asperity results in the same texturing being used for interactions with fine grained soils, coarse grained soils and geotextiles and also at low and high confining stresses. The main gaps in knowledge to be addressed are as follows: 1. What are the physical mechanisms that develop peak strength in geomembrane-soil and geomembrane-geosynthetic interfaces? 2. How do these mechanisms differ for interactions with geotextile, coarse grained soil and fine grained soils? 3. Can the nature of the geomembrane surface be designed to better transfer and distribute load, to produce an interface with higher strength? The project will use scanning electron and optical microscopes to study material interaction to determine how peak strength is mobilised and from these studies produce CAD models of high strength interfaces. The CAD models shall be converted into physical models through 3D printing allowing their interaction with soils and geotextiles to be observed and quantified. The work will allow design of geomembrane surfaces for interaction with typically used materials. The designed interfaces will have greater peak strength and allow designers to understand and specify the characteristics of interface shear strength beyond simply asperity height. In practical terms it will allow higher and steeper slopes when using geomembrane barrier systems offering improved project profitability.

The UK and the European Union have legally binding targets for reducing carbon dioxide emissions and for the increasing renewable energy generation. As about 25% to 33% of the UK's annual energy usage is expended on space heating, the provision of renewable heat energy is an area of critical importance if emissions and energy targets are to be achieved. Increased use of ground energy systems within foundations and other underground structures would be beneficial in both these respects, and will be eligible for financial support through the forthcoming government Renewable Heat Incentive. However, despite a recent increase in the use of ground energy systems, there remain key areas of uncertainty about their performance. This is especially important in the long term, where multiple installations will interact with each other and where unbalanced heating or cooling loads will lead to changes in the thermodynamic regime in the ground. This project aims to address some of the uncertainties surrounding ground energy systems installed in foundations by comprehensively instrumenting and monitoring two sites in contrasting ground conditions. This will allow the real response of the ground to known heating and cooling loads to be measured, and comparisons made with predictions based on analytical and numerical models. The use of contrasting geological regimes will allow investigation of the impact of groundwater on the performance of systems, something rarely considered and not well understood. The field monitoring will be accompanied by a programme of in situ and laboratory testing to assess differences in thermal behaviour at different scales and temperatures relevant to ground energy systems. The testing programme will address questions relating to degrees of uncertainty in determining key thermal properties and how this may compare with other uncertainties in the system design, such as heating/cooling loads. Numerical modelling, including back analysis of the in situ thermal response testing and operation of the ground energy systems, will allow assessment of the sensitivity of the systems to different input parameters. The modelling will also allow evaluation of the numerical and analytical techniques currently used for the design of ground energy systems and assessment of the importance of key factors (geological variation, groundwater, surface boundary conditions, geothermal gradient) not currently accounted for in existing methods. Taken together, the various strands to the project are expected to provide an important dataset which will add substantially to the understanding of the performance of ground energy systems. By addressing uncertainties surrounding design input parameters, geological conditions and design approaches, the project will also provide relevant lessons for direct application to the design and construction of ground energy systems installed in foundations, which it is expected will ultimately form part of improved guidance for industry.

The UK's transport infrastructure is one of the most heavily used in the world. The rail network takes 50% more daily traffic than the French network; the M25 between junctions 15 and 14 carries 165000 vehicles daily; London Underground is Europe's largest subway. The performance of these networks is critically dependent on the performance of cutting and embankment slopes which make up £20B of the £60B asset value of major highway infrastructure alone. Many of these slopes are old and suffering high incidents of instability (increasing with time). Our vision is to create a visualised model of transient water movement in infrastructure slopes under a range of current and future environmental scenarios, based on a fundamental understanding of earthwork material and system behaviour, which can be used to create a more reliable, cost effective, safer and more sustainable transport system. The impact of the improved slope management will be highly significant in both direct economic and indirect social and economic terms: planned maintenance costs 10 times less and reduces delays caused by slope failure. This proposal offers a unique opportunity to unite 6 academic institutions and coalesce their field, laboratory and computing facilities; with a large cohort of PhD students and experienced stakeholder community we will undertake world leading science and create a long-term legacy. Individually, the partners in this proposal, in collaboration with key infrastructure owners and engineering companies, have been responsible for the instrumentation of 15 cut slopes and embankments, the development of numerical models which couple hydrological and geotechnical effects, and the development of laboratory and filed testing to provide parameters to populate these models. These studies have helped to define the type of problem that is being faced and begin to understand some of the interactions between weather, soil and vegetation. However, further research is required in order to better understand material behaviour (particularly the composite behaviour of soil, water, air and vegetation); slope system behaviour (particularly the effects of temporal and spatial variations of material properties) and the relationships with environmental effects and engineering performance. Furthermore, the integration of the material and slope behaviour with that of the behaviour of the infrastructure network as a whole has thus far not been possible. It is important for the sustainable management of infrastructure slopes (assessment, planning, repair, maintenance and adaptation) to have models that can assess the likely engineering performance of infrastructure slopes, both now and in the future. Recent model development has started to consider the input of weather patterns, and can therefore model the potential effects of future climate. However it has become clear that these models are sensitive to the way in which a number of the physical processes and properties are incorporated, many of which are complex and difficult to quantify directly. A better understanding of the interactions between earthworks, vegetation and climate is required to formulate robust guidance on which maintenance approaches should be adopted and how they should be applied. iSMART will use a combination of field measurements, lab testing and development of conceptual and numerical models to investigate the uncertainties and knowledge gaps enumerated above and to visualise the complex interactions taking place over time and space. This knowledge will help the managers of the UK's transport infrastructure to identify problem sites, plan and prioritise maintenance activity, and develop assessment and adaptation strategies to ensure future safety and resilience of geotechnical transport infrastructure.