Membrane distillation for sustainable desalination and water treatment

The world, including the UK, is currently facing the need for producing fresh water from sources other than rivers, ponds or lakes. It is of paramount importance for countries where freshwater resources are limited, but also for regions that can suffer from unexpected draughts. Demand for fresh water for human use and industrial activities worldwide are 10 and 20%, respectively (agriculture accounts for the remaining 70%). However, in industrialised nations, industries consume more than half of the water available for domestic use. Policies regulating the quality of water that can be discharged back into rivers or other water-bodies is becoming stricter worldwide, and therefore is crucial to advance on the use of technologies that can generate the water with the required quality but lower foot print and more economically than the conventional technologies currently used. Thus, the aim of this project is to advance on the use of a sustainable technology for water purification (membrane distillation, MD) by developing highly permeable graphene-based membranes with long term stability (i.e. anti-wetting properties). MD is considered to be sustainable as the low-grade thermal energy required to do the separation can be obtained by means of thermal solar collectors or waste heat from power plants and other industrial operations. In addition, it allows to treat highly saline brines with 100% rejection of impurities in a single stage process, with no need for costly pressurised membrane systems, as it is operated under atmospheric pressure. Furthermore, the developed MD membranes can propel the separation efficiency and recovery of valuable products from desalination brines and wastewater effluents in a range of industrial processes including the textile industry.

The aim of this project is to develop a new class of membranes based on graphene laminates for desalination and wastewater treatment applications via membrane distillation (MD). This research falls within one of the Eight Great Technologies that will propel the UK to future growth: Advanced Materials and nanotechnology which specifically points out at forms of carbon i.e. graphene and nanostructures as one of the four areas in this Great Technology. At the same time, water engineering is a relevant and growing EPSRC's challenge theme.
Academic beneficiaries: Short-term academic impact is the first step to achieving longer term economic and societal impact. Consequently, all new results generated in this project will be actively disseminated to the scientific/engineering community through appropriate publications in high impact journals, talks and contributions at international conferences in the fields of membrane technology, materials science and chemical engineering. The PI, PDR and PhD student working in this project will obviously benefit from the publication of the findings, as it will increase their reputation as world-leaders in graphene-based membranes and membrane distillation research. In addition, this project will contribute to maintain the University of Manchester and UK's leading positions in graphene research. Meetings and interactions with other scientists and industrialist at international conferences will likely result in cross-disciplinary research collaborations that could potentially expand the use of such membranes to other separations.
Commercial beneficiaries: As a result of this project, membranes with higher and more stable water flux in membrane distillation and anti-wetting properties will be available for desalination and waste water treatment applications in industries such the textile and seawater reverse osmosis plants. Scientists and Chemical Engineers will benefit directly from the findings of the proposed research, giving them a new tool to increase the sustainability of their separation processes, via the increased water production and/or the extraction of valuable compounds from the brines and concentrated wastewater residues coming from reverse osmosis systems. A one-day showcase will be organised towards the end of the project with the purpose of gathering an invited group of companies interested in the exploitation of this next-generation of MD membranes commercially.
The general public: The PI, PDRA, and the PhD student working on this project will communicate the importance of this work to the general public through outreach activities; at least two science festivals such as Discover Engineering Day and a couple of talks at other events such as societal meetings, will be attended during the course of the project. Moreover, these dissemination activities will be accompanied by online publications of the latest achievements via social networking sites, and the research group homepage.