Browsing by Author "Tierney, Ross"

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    The development of the user interface of an innovative sanitation solution targeted at developing countries
    (Cranfield University, 2014-03) Tierney, Ross; Williams, Leon; Franceys, Richard
    Case Study Impact Statement. Around the World, 2.6 billion people do not have access to a toilet, leading to the deaths of 1.5 million children per year through associated diseases (Kone, 2012). Novel approaches to this problem are needed that utilise the latest research and technology to safely deal with human waste in developing countries. These new sanitation methods have to be carefully developed to meet the needs and aspirations of their target audience. The Bill and Melinda Gates Foundation are seeking to address this with an international competition called the ‘Reinvent the Toilet Challenge’. The winning entries from different universities will employ the latest technology and research to safely deal with the waste and to utilise the potential of the waste. Executive Summary. This thesis will provide academics and new product development (NPD) practitioners with a strategic methodology for a design-thinking based approach to design products for developing countries. This transfer of knowledge will be possible by discussing potential methods before selecting the most appropriate to utilise with the use of a Case Study to give context. The research will commence with a scoping phase to show methods of gaining understanding of the wider problem followed by approaches to down select and synthesise this information into appropriate project requirements. When clear direction has been established, the implementation and development can take place to produce an outcome to meet the project requirements. Suitable validation techniques will be used to ensure the success of the research. The Case Study that will be used is focused on the development of a user interface for a new sanitation system for developing countries. The system is being developed by Cranfield University, as part of the Reinvent the Toilet Challenge funded by the Bill and Melinda Gates Foundation.
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    Figures and tables from "Hybrid membrane distillation reverse electrodialysis configuration for water and energy recovery from human urine: An opportunity for off-grid decentralised sanitation."
    (Cranfield University, 2019-05-15 14:12) Mercer, Edwina V.; McAdam, Ewan; Davey, Christopher J.; Pidou, Marc; Tyrrel, Sean; Williams, Leon; Jiang, Ying; Parker, Alison; Tierney, Ross; Azzini, Daniele; Eusebi, Anna
    This data compiles the dataset required to generate the tables and figures for the paper - "Hybrid membrane distillation reverse electrodialysis configuration for water and energy recovery from human urine: An opportunity for off-grid decentralised sanitation."
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    Hybrid membrane distillation reverse electrodialysis configuration for water and energy recovery from human urine: an opportunity for off-grid decentralised sanitation
    (Elsevier, 2019-05-06) Mercer, Edwina V.; Davey, Christopher J.; Azzini, D.; Eusebi, Anna L.; Tierney, Ross; Williams, Leon; Jiang, Ying; Parker, Alison; Tyrrel, Sean; Pidou, Marc; McAdam, Ewan
    The integration of membrane distillation with reverse electrodialysis has been investigated as a sustainable sanitation solution to provide clean water and electrical power from urine and waste heat. Reverse electrodialysis was integrated to provide the partial remixing of the concentrate (urine) and diluate (permeate) produced from the membrane distillation of urine. Broadly comparable power densities to those of a model salt solution (sodium chloride) were determined during evaluation of the individual and combined contribution of the various monovalent and multivalent inorganic and organic salt constituents in urine. Power densities were improved through raising feed-side temperature and increasing concentration in the concentrate, without observation of limiting behaviour imposed by non-ideal salt and water transport. A further unique contribution of this application is the limited volume of salt concentrate available, which demanded brine recycling to maximise energy recovery analogous to a battery, operating in a ‘state of charge’. During recycle, around 47% of the Gibbs free energy was recoverable with up to 80% of the energy extractable before the concentration difference between the two solutions was halfway towards equilibrium which implies that energy recovery can be optimised with limited effect on permeate quality. This study has provided the first successful demonstration of an integrated MD-RED system for energy recovery from a limited resource, and evidences that the recovered power is sufficient to operate a range of low current fluid pumping technologies that could help deliver off-grid sanitation and clean water recovery at single household scale.
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    The potential of reverse innovation to improve urban toilets
    (2017-12) Tierney, Ross; Williams, Leon; Rao, Jeff
    The lack of desirable, waterless toilet options in urban environments around the world leads to major issues that will continue to get worse as population density increases. At the bottom of the economic pyramid, 2.3 billion people lack access to adequate sanitation accelerating the spread of disease through contaminated water and leading to the deaths of over a million children per year. At the top of the economic pyramid, the ubiquitous flushing toilet uses nine litres of water per flush, equating to the average person using 15,000 litres of water per year. As clean water becomes a scarcer resource, wasting and polluting water has to be avoided. Developing new water-saving, desirable toilets to provide a pleasant user experience will increase the likelihood of adoption of more sustainable options. Defecation is a basic human function but also a universal cause for embarrassment and disgust. As the repulsion is visceral and ‘hard-wired’ human behaviour, many of the same issues arise whether the user is in the poorest slum or a modern apartment building. Designing new products for low income countries that find a secondary market in a high income country is an approach called reverse innovation and has a proven record of producing disruptive innovations by working to strict requirements. This research discusses how reverse innovation has potential to address the challenges and issues associated with low-water sanitation to increase adoption of more sustainable technology. To achieve this, an understanding was gained of the user experience of different low-water toilets through literature review and an ethnographic study in Kumasi, Ghana. A new waterless toilet technology was then developed and tested, primarily targeting the residents of Kumasi before being tested with a secondary target market in the United Kingdom. There were a number of similarities across both target markets, confirming the importance of user experience. The technology was positively received and compatible with user behaviour in the secondary target market indicating the technology could be transferred and an example of reverse innovation. This research intends to encourage and inspire innovation in a sector that effects everyone in the world yet remains an ignored and embarrassing subject.
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    Viscoelastic solid-repellent coatings for extreme water saving and global sanitation
    (Nature Research, 2019-11-18) Wang, Jing; Wang, Lin; Sun, Nan; Tierney, Ross; Li, Hui; Corsetti, Margo; Williams, Leon; Wong, Pak Kin; Wong, Tak-Sing
    Water scarcity threatens over half of the world’s population, yet over 141 billion litres of fresh water are used globally each day for toilet flushing. This is nearly six times the daily water consumption of the population in Africa. The toilet water footprint is so large primarily because large volumes of water are necessary for the removal of human faeces; human faeces is viscoelastic and sticky in nature, causing it to adhere to conventional surfaces. Here, we designed and fabricated the liquid-entrenched smooth surface (LESS)—a sprayable non-fouling coating that can reduce cleaning water consumption by ~90% compared with untreated surfaces due to its extreme repellency towards liquids, bacteria and viscoelastic solids. Importantly, LESS-coated surfaces can repel viscoelastic solids with dynamic viscosities spanning over nine orders of magnitude (that is, three orders of magnitude higher than has previously been reported for other repellent materials). With an estimated 1 billion or more toilets and urinals worldwide, incorporating LESS coating into sanitation systems will have significant implications for global sanitation and large-scale wastewater reduction for sustainable water management.