The research will centre on reducing the production of nitrous oxide, the greenhouse gas 310 times more damaging than carbon dioxide on a weight for weight basis, during water and wastewater processing. Suitable candidates for the PhD may have a background in biological sciences (including biochemistry and microbiology) chemistry, environmental sciences or chemical engineering. The aim of the research is to investigate the mechanisms of nitrous oxide formation in a novel membrane oxygenated biological process for wastewater treatment from a demonstration plant sited in Cambridge. The biological process receives oxygen from an electrolyser that is producing hydrogen from wastewater effluent: this is summarised in the diagram below and the video at https://waterinnovation.challenges.org/winners/triple-carbon-reduction/. Microbially mediated pathways are critical in the production and attenuation of nitrous oxide depending on the environmental conditions in a system. Mass and energy balances will be conducted on the demonstration plant to establish nitrous oxide emissions and the effect of mitigation measures. Cranfield University is an exclusively postgraduate university focussed on technology and management. The Water Theme (www.cranfield.ac.uk/themes/water/about-us) is the largest dedicated academic centre focussed on water and wastewater science, engineering and management in the UK. Researchers come from backgrounds in biological chemical and physical sciences, environmental science and management, engineering disciplines as well as management and social sciences. The PhD will have access to the comprehensive laboratory resources and technician support in the Environmental Analytical Facility (www.cranfield.ac.uk/facilities/environmental-analytical-facility). Results of the research will enable lower greenhouse gas emissions through production of hydrogen combined with efficient wastewater treatment to protect the environment and deliver net zero carbon emissions for society. The project offers the unique opportunity to work on a cutting-edge wastewater treatment technology, a pure oxygen version of the Membrane Aerated Bioreactor (MABR), as part of a £3.5 million OFWAT (the water services regulator) Innovation Fund project. As well as staff and colleagues at Cranfield, you will be interacting with the wider project team led by Anglian Water with partners Oxymem, Element Energy Ltd, Jacobs, University of East Anglia, Brunel University, Severn Trent, Scottish Water, Northern Ireland Water and United Utilities. You will be expected to deliver at least one presentation at a major international conference such as the International Water Association (IWA) Biennial Congress. As a student within the WIRe CDT (https://cdtwire.com/) you will also be an essential member of the 2022 cohort that includes students from Newcastle and Sheffield Universities. At the end of the PhD, the successful candidate will have developed skills for roles in academia, government and industry. As well as being able to deliver research, you will have gained transferable skills in communication, data analytics, digital, project management and writing that will be invaluable for management and leadership careers in business, government and universities.