Inadequate access to clean water is hugely detrimental both to economic development and human health. In the developing world 3900 children die daily from diseases transmitted through unsafe water and 1.2 billion people lack access to safe water (1). Even in the developed world, waterborne pathogens can cause huge problems, in terms of both public health and lost productivity. For example, in the past few years cryptosporidiosis outbreaks in the UK have infected hundreds of people and resulted in hundreds of thousands of households being issued with boil water notices (2). As the population continues to grow, increased industrialisation occurs and climate change reduces freshwater supplies, the problem of water scarcity will intensify (1). One of the biggest challenges is to detect the presence of pathogens, especially those present at low level concentrations. The rapid and robust detection of pathogens is required in the water industry to monitor the integrity of existing treatment facilities and in international development to rapidly and accurately obtain analytical data on water quality in the field. A Scottish Water R&D aim is to achieve zero-disruption to the public, while safeguarding drinking water quality. Therefore, rapid and accurate methods to monitor water for pathogen presence are required. Current methods to indicate, e.g. cryptosporidium presence take around 3 days. Furthermore, the method does not indicate viability or species, which is essential information to determine whether the detected oocysts are pathogenic to humans and to decide on appropriate response strategies. The ideal solution would be an online automated detection system linked to methods for rapid determination of species and viability. We propose a novel biosensing approach for more rapid detection of waterborne pathogens with the aim of incorporating sensors into online automated systems. The recognition of the pathogen utilises imprinted polymers, which provide a low-cost and robust alternative to the current antibody-based recognition, and have previously been used to detect benzimidazole in water (3). The signal transduction will be performed by low-cost, wireless magnetoelastic (ME) sensors (4); such sensors have been used to detect pesticides in water (5). The project will investigate various techniques for the synthesis of imprinted polymers, on ME sensors, capable of specific detection of pathogens of interest to the water industry. This project will focus upon cryptosporidium, further work will extend to Giardia and bacteria. While the above technology will indicate pathogen presence, it is extremely desirable to obtain further information about the detected pathogen, e.g. speciation and viability. To provide information about which species of pathogen is present, we will investigate lab-on-a-chip PCR. Microfluidic PCR systems allow for rapid temperature cycling and Zaysteva et al demonstrated an assay of pathogen RNA on a PDMS microfluidic system in just 15 mins (6). Scottish Water have demonstrated 80% successful PCR from one cryptosporidium oocyst, although 24hrs is required for testing. We will study whether similar success rates can be achieved, in considerably shorter timescales, when this protocol is adapted for incorporation into a microfluidic device. 1. Shannon et al, Nature 2008 452 301 2. http://www.cieh.org/policy/cryptosporidium_outbreaks.html 3. Cocha et al, Talanta 2009 78 1029 4. Grimes et al, Sensors 2002 2 294 5. Zourob et al, Analyst 2007 132 338 6. Zaysteva et al, Lab Chip 2005 5 805

Clean drinking water is vital for human life. Water is also essential to agriculture, energy and manufacture. The United Nations recently reported an expected increase in demand for water of 55% by 2050. The reliable and sustainable provision of clean water for all is urgently needed worldwide, and is the focus of one of the Sustainable Development Goals established by the UN (Goal 6). In a scenario where conventional water resources are becoming increasingly insecure and contaminated, the development of new improved and resilient water treatment technologies is imperative to meet the UN's target. This proposal takes an important step towards a solution involving membrane filtration in water supply. Nanofiltration (NF) and reverse osmosis (RO) membrane processes are increasingly popular as they supply high quality water, including drinking water, from any available water source. A high pressure feed water is filtered through the membrane, producing permeate, i.e. clean water, whilst contaminants are retained on the feed side. Membranes are however known to foul due to an accumulation of contaminants on the membrane surface. Biofouling in particular, is caused by the accumulation, adhesion and growth of microorganisms on the membrane surface leading to dangerously reduced quality and flow of permeated water, increased operational and energy costs and membrane life reduction. Chemical cleaning regimes, such as chlorination, are used to combat membrane biofouling. These processes are inefficient and they require process downtime. They can also modify the properties of the membrane, ultimately reducing its life. This project will demonstrate a simple, novel cleaning technique to prevent biofouling formation on NF and RO membranes. We will explore the regular introduction of a burst of high salinity - a High Salinity Pulse (HSP) - into the input feed flow of the membrane. The HSP causes a high osmotic pressure difference to occur between the feed and permeate sides of the membrane. As a consequence, the direction of water permeation through the membrane temporarily reverses, flowing from the permeate side to the feed side. The membrane is backwashed and adhered microorganisms removed from the surface, avoiding growth and subsequent biofilm formation. This will maintain water production quantity and quality at lower operational and energy costs and extend the usable lifespan of a membrane, having an immediate transformative effect on industries where NF and RO membranes are used, which include the water, wastewater, aquaculture and food & drink industries.

Here we argue that decentralised and point of use water infrastructure and technologies are fundamental in delivering health and economic sustainability in rapidly growing cities of the Global South. Further we advocate that research on decentralisation with developing world partners has the potential to catalyse radical change in unsustainable centralised western practices and thus will be mutually beneficial. There has been significant investment by charities and government agencies in developing novel wastewater treatment technologies and many are now close to market readiness. The Asian Institute of Technology in Thailand are piloting a suite of novel market-driven decentralised biological wastewater treatment technologies that were developed with Bill & Melinda Gates Foundation funding. The technologies work but their performance is variable. There is evidence that this is caused by variability in the microbial populations at the heart of the technologies, which are poorly understood. We will work with AIT to characterise and optimise the structure and function of the microbial treatment communities. The aim will be to mitigate the risk of failure by refining the AIT designs and offering rapid low-tech remediation strategies that can be deployed by customers should failures occur.

Recycling urban wastewater into usable clean water is an environmental win. Using renewable energy to power this process reduces its carbon footprint and makes this idea even better. What about obviating waste generation from this low-carbon process by recovering waste components as resources without using chemicals that typically generate more waste? With 380 billion cubic metres of municipal wastewater produced globally in 2020 where every litre of this wastewater contains 0.75 mg of Zn, 285,000 metric tonnes of Zn can be recovered from global municipal wastewater. This is about 2% of the world's total Zn consumption in 2021. In a UK context, about 4300 tonnes of Zn can be recovered from UK municipal wastewater per year - about 5% of the Zn imported into the UK. However, the recovery of heavy metals from municipal wastewater is not practiced currently and these valuable resources are lost to the environment as the effluents of treated wastewater are discharged into the environment. This is due to the low metal concentrations in this wastewater and the recovery of metals from such dilute mixtures with legacy technologies typically create more waste. Moving towards a circular economy, it is crucial that these valuable metals are reclaimed without creating more wastes in its own right. To solve such a global challenge, there is a need to re-think how metal-metal separations should be achieved, where the current focus is only on recovering metals from waste streams with high enough metal content. We should also consider how this process can be achieved in-situ of existing processes as well as obviating waste generation associated with chemicals used for separating metals from each other or to regenerate separation media. In this Fellowship I propose to design and engineer photo-responsive covalent organic frameworks, a class of microporous polymers with tailorable pore sizes, to achieve zero-waste specific metal-metal separations in-situ of desalination. I will use recent advancements in photo-modulated desalination to engineer a library of covalent organic frameworks that can specifically and reversibly complex with a target metal cation, separating various metal types from each other in complex and dilute mixtures into reusable high-purity metal streams. Light-responsive, zwitterionic molecules can separate cations and anions from water, and monovalent cations from divalent ions, as a function of their tailorable metal compatibility via chemical functionalisation. With training in computational simulations , I will design a series of chemically-functionalised zwitterionic photo-switches that can be embedded within the pores of covalent organic frameworks to separate metals from each other via a novel separation mechanism underpinned by size selection and specific metal complexation. I will validate the concept of light-controlled specific metal-metal separation in-situ desalination using these novel materials as adsorbents and membranes in bench-scale experiments using model and complex mixtures and real-world municipal wastewater samples. I will close the desalination waste loop associated with fabrication and end-of-life of desalination media by exploring the use of additive manufacturing technologies that reduce waste generation during membrane fabrication and depolymerisation techniques to recycle spent desalination media into reusable chemical compounds, respectively. Beyond exploiting the concept of light-controlled specific separations to unlock desalination as a circular economy solution, I will work with other researchers to explore using this technology in other applications such as organic solvent nanofiltration, drug delivery, self-cleaning coatings. I will also perform life cycle assessment studies to evaluate the sustainability and feasibility of technologies developed here for metal recovery from municipal wastewater.

Scottish Water has identified the need to develop their approach to dealing with uncertainty when assessing the risk of river erosion at pipeline crossings. In particular, there is a need to develop and pilot methods that can use data from initial asset inspections to quantify risks and uncertainties in making decisions on where to invest additional resources in more detailed inspections, for assets deemed to be at greater risk from river bank erosion or scour around bridge abutments. This challenge arises from the reality that, over the past 10-15 years, pipeline crossing inspections have been undertaken in an ad-hoc manner. The aim of this proposal is, therefore, to develop a decision support framework to incorporate river bank stability in pipeline crossing risk assessment. This will be used immediately during 2016 in Scottish Water's first, national-scale pipeline bridge asset inspection programme. The specific objectives are to: (i) evaluate uncertainty in the existing low-cost app-based inspection database that is used to screening risk; (ii) assess the uncertainty that arises from the initial desk-based phase of river bank stability assessment; (iii) develop a pipeline crossing scour assessment framework for analysing river bank stability at the screening phase and determining appropriate analysis for the initial assessment phase; and (iv) recursively test the risk assessment framework. To address these objectives there will be three methodological phases, results from which will be progressively reported. First, a sample of the pipeline crossings will be re-surveyed using a replicate inspection app. Results will enable evaluation of uncertainties in data capture and their consequences for river stability decision making at the screening stage of risk management. Second, uncertainty in assessing bank erosion will be assessed considering data from the asset inspection app, Google Earth imagery, high-resolution aerial images commissioned by Scottish Water, and legacy LiDAR acquired by the Scottish Government. Evidence of river instability will be mapped from imagery. Change will be quantified using appropriate techniques to represent errors in digitising and topographic change analysis. Finally, results will be used to produce a framework to: (i) characterise risk during screening; and (ii) determine the most appropriate forms of desk based analysis for initial risk assessment. The framework will include a multi-criteria process for calculating risk after the initial assessment phase to determine whether a more detailed assessment phase is necessary and, if so, necessary actions. This framework will be tested at a further set of 20 sites. Project outputs will be operationalised and used to improve decision making. App-based data capture will be improved with enhanced data fields and training material for asset inspectors. Results from evaluating uncertainty in data and analysis will be input to a multi-criteria scoring framework that will improve decision making at the screening and initial assessment stages and will thus enable scarce resources to be prioritised for desk-based river bank stability analyses. The framework will be used in the current drinking water pipeline crossing inspection programme and will also be of value for a future waste water pipeline crossing inspection programme. The project will last 12 months which will enable evaluation of uncertainty in a sufficiently large sample of data, analysis approaches and sites. The total cost (80% FEC) of the project is £89,707. This includes staff costs for Williams and Hoey, 9 months research assistant time, computer hardware, and travel.