
CASE STUDY ECI
Waste not, want not: a circular economy approach to nutrient flows
Photo: Kawee – stock.adobe.com
Can we turn waste into fertiliser?
How to capture the valuable nutrients running away down our sewer pipes? How to prevent excessive nutrients causing catastrophic damage to our waterways? These are the questions the Environmental Change Institute at the University of Oxford sought to address in an innovative multidisciplinary 12-month sprint project. They focused on how the UK could better keep nitrogen and phosphorus in circulation, as precious resources that are lost in significant volumes in current waste management processes. 3Keel was commissioned as a key partner in the research, bringing combined sustainability, business and innovation expertise.
What’s the issue?
Synthetic fertilisers and manures represent 5% of the world’s greenhouse gas emissions. This is more than global aviation and shipping combined. Furthermore, phosphorus is a scarce and non-renewable resource that is considered essential for food production.
Nitrogen and phosphorus travel around our biophysical system – from soils, into plants and animal products consumed by humans, into the food waste and the wastewater system, and from there, more often than not, back into the wider environment. What is more, nitrogen and phosphorus applied to farmland often does not even get taken up by plants, instead building up in soils or running off into watercourses, where it has harmful effects on aquatic life.
These valuable nutrients are routinely going to waste, causing unnecessary greenhouse gas emissions, additional costs to farmers and water companies, and damage to biodiversity. There is a huge opportunity to build circular economy solutions that make efficient use of nutrients and keep them circulating in the food system. This requires a shift in thinking – where some see waste, we need to see valuable resources.
The project
The Oxford Martin School’s Agile Initiative is designed to bring together the best interdisciplinary research teams with policymakers, industry partners, NGOs and local communities in rapid research ‘sprints’, representing a new model for collaborative academic impact. 3Keel partnered with Oxford academics on the Nutrient Flows sprint from July 2022 – September 2023, with the aim of identifying innovative opportunities to transform flows of nitrogen and phosphorus to keep more nutrients in circulation.
The project focused on a particular region – Leicestershire county and Leicester city – in collaboration with local stakeholders, with the intention that applied learnings could be transferred to other regions and inform national and local policy-making and implementation. Our work complemented the research of the academic teams undertaking detailed nutrient modelling and stakeholder engagement, by focusing on the key opportunities for business innovation to provide actionable solutions.
3Keel’s Work
For the first part of our work, in autumn 2022, we focused on developing ‘search criteria’ for business clusters that would engage in the types of innovation involved in this project. In consultation with the academic team, we identified eight initial problem areas with the potential for solutions to improve circularity and reduce nutrient losses.
In spring 2023, we produced an initial, internal report, ‘Business Needs, Opportunities and Challenges’, based on in-depth interviews with stakeholders in wastewater processing, agriculture and regenerative agriculture, nutrient recovery technologies, green waste processing, food manufacturing, water and academia.
From an initial list of key opportunities, in summer 2023, we focused in on the four of greatest interest to the stakeholders in further interviews and workshops:
- Upstream wastewater solutions – intervening prior to nutrients entering the wastewater system, through solutions like sustainable urban drainage systems (SUDS), large-scale urine separation and microalgae cultivation in nutrient-rich wastewater flows.
- Transformation of digestate – using technologies such as struvite precipitation, ammonia stripping and ‘dry’ anaerobic digestion to ensure that the nutrients contained within digestate can be more fully deployed on crops. We highlighted innovative companies who are already piloting similar technologies to produce low carbon fertiliser from waste.
- Downstream farming interventions – farming differently to apply nutrients more sparingly and preventing loss to the wider environment, through regenerative farming practices and new business opportunities around precision agriculture and accurate soil sampling and mapping.
- Nutrient co-location – tackling the challenges associated with moving nutrient-rich materials by situating sources and uses close together, for example co-locating anaerobic digestion facilities with potential nutrient use cases in horticulture, and promoting opportunities to re-establish mixed farming where manures and slurry can be utilised on-site.
We identified the key actors, barriers and enablers, and spelt out the specific solutions within each of the four areas that could be taken up in Leicestershire, in a pioneering capacity. Critically, we looked at the need for multiple stakeholders to come together to overcome regulatory, policy, financial and technical barriers, to shift from seeing nutrients in certain contexts as a problem to be dealt with, to an opportunity to be capitalised on.
The Output
The Nutrient Flows project as whole provides an important contribution to rethinking waste, by quantifying the scale of the opportunity within Leicestershire and engaging key stakeholders in dialogue around future directions. Importantly, with 3Keel’s help, the project identified where and how moving towards a circular economy can present an opportunity for forward-thinking businesses to flourish through innovation. The project’s report, Re-organising Nutrients Flows In Leicestershire, was published in December 2023.
While the opportunities are there, the report highlighted that many of them may only be fully realisable through policy change. Some opportunities have been explored for decades but are held back from reaching commercial viability because of systemic lock-in to current practices and regulations. This is therefore a prime space for ‘systemic innovation’, where stakeholders across the system need to align from an early stage to co-create and pilot solutions together, identify barriers and work with singular focus to remove them.
Added value from 3Keel
Project Lead, Professor Aidong Yang says: “3Keel’s experience in convening and consulting stakeholders, combined with their consultants’ knowledge across water systems, agriculture, circular economy, and business was invaluable for this project. Their expertise in these areas gave us confidence to bring them on board to complement the work of the academic team and they delivered what we needed.”