Every year the world generates billions of tonnes of waste while extracting ever more raw material to replace what it throws away. We work on both halves of that paradox: recovering energy, nutrients and clean water from organic waste streams, and redesigning the systems, materials and infrastructure that decide whether a resource is recovered or lost.
Why It Matters
Waste is where three crises meet. It is a public health problem, because badly managed waste exposes people to pathogens and pollutants, most acutely for the workers and communities living closest to it. It is a climate problem, because organic waste releases methane, and because everything we discard and replace carries the carbon of making it again. And it is a resource problem, because the nitrogen, phosphorus, carbon and energy locked in waste streams are precisely the things a growing population needs.
The circular economy is often discussed as though the barriers were technical. Mostly they are not. The harder questions are about quality, value, governance and business models: whether recovered material is good enough to use, whether anyone will pay for it, and whether the institutions exist to make it happen. Our research spans both, from the microbiology of a digester to the policy of a national resources strategy, and it holds onto the public health question that runs through this group: does this make people safer, or not?
What We Do
Energy and nutrients from organic waste
The core of our BioResource Systems research. Miller Camargo-Valero, Associate Professor of BioResource Systems, leads work on wastewater and faecal sludge treatment, microalgal technology, and the recovery of energy and nutrients from organic waste, connecting this theme directly to our sanitation and WASH research.
Cynthia Okoro-Shekwaga, a BBSRC Discovery Fellow, works on anaerobic digestion, biomethanation and biohydrogen. Her research targets a specific and demanding goal: producing biomethane from food waste clean enough to replace petrol and diesel in vehicles, which could cut vehicle emissions substantially, without the energy penalty and carbon release of conventional biogas upgrading. It also confronts a practical reality of real waste streams, which is that they vary. A digester fed a sudden glut of a seasonal crop behaves differently from one fed a steady diet, so characterising what is actually in the feedstock is part of the engineering.
Franja Prosenc recovers and recycles nutrients from wastewater, liquid digestate and fish farm effluents using microalgae and duckweed, and is developing microalgal carbon capture to clean CO2 impurities from biogas and biohydrogen. Her work also covers contaminants of emerging concern, including the algae-based removal of endocrine-disrupting plasticisers.
Louise Fletcher leads BEFWAM, a BBSRC-funded project turning invasive aquatic macrophytes, a serious ecological problem in many tropical waterways, into bioenergy, fertiliser and clean water.
Circular economy, materials and infrastructure
Anne Velenturf, Senior Research Fellow in Circular Economy, works on the systems, governance and business models that determine whether a circular economy actually happens. She led the £7 million Resource Recovery from Waste programme, funded by NERC, ESRC and Defra, which changed UK government strategy and industry practice on resources and waste, and she is Technical Programme Manager of TransFIRe, the Transforming Foundation Industries Research and Innovation Hub. She leads the Yorkshire Circular Lab, a living lab supporting companies, councils and communities through the circular transition, and the Wind Energy Lifecycle Sustainability group, applying circular economy thinking to the decommissioning of infrastructure across offshore wind, oil and gas, mining, and transport. She advises government bodies, research councils and industry.
Microplastics and emerging contaminants
Plastics do not disappear; they fragment. Franja Prosenc works on microplastic prevalence in agricultural soils, including the methodological problem of how to extract microplastics reliably from complex matrices such as compost, and on how microplastics interact with pesticides and biomass in soil. Louise Fletcher works on microplastics alongside her wider environmental microbiology research.
The health of waste workers and communities
Waste is a public health issue, and the risk is not evenly shared. Louise Fletcher and Barbara Evans have quantified the bioaerosol exposure of workers at open dumpsites, including at the Olusosun dumpsite in Lagos, and used quantitative microbial risk assessment to estimate the resulting infection risk from pathogens such as Aspergillus fumigatus and E. coli. Fletcher's wider aerobiology research covers the generation, dispersal and control of bacterial and fungal pathogens during composting and biowaste treatment, and the performance of biofilters in abating them. This is the point where this theme meets our indoor air and bioaerosol research: the same science, applied to the people who handle our waste.
Bio-mediated ground processes
Shashank Subramanyam works on biogeotechnics and the bioremediation of contaminated ground, using biological processes to treat and stabilise soils, linking this theme to our water and geoenvironmental research.
The Computational Thread
Recovery processes are physical and biological systems, and they can be modelled. Duncan Borman develops computational fluid dynamics for the non-Newtonian mixing inside anaerobic digesters, which governs how much energy a digester consumes and how well it performs. It is a good example of how the group's data-driven and computational methods work reaches into every theme.
Facilities
Our public health laboratories include dedicated areas for solid waste, water and wastewater, alongside a Class II microbiology laboratory and clean room, and facilities for anaerobic digestion and microalgal cultivation.
[Confirm the current list of BioResources-specific kit: digesters, algal ponds or photobioreactors, and any solid waste characterisation equipment.]
Partnerships
Our researchers work with government bodies, research councils and industry across the UK, and hold active international partnerships including in Slovenia, Mexico, Taiwan, Indonesia and Colombia. The theme connects to the Global Food and Environment Institute and water@leeds.
Study With Us
We supervise doctoral research across bioresource systems, circular economy, microplastics and waste-related public health. We welcome students from engineering, environmental science, biotechnology, microbiology and the social sciences.
Work With Us
If you produce a waste stream, manage one, or regulate one, we would like to hear from you.