Jenna Senecal, Prithvi Simha, Evelina Vinnerås, Nicola Parfitt & Björn Vinnerås: Circular sanitation takes the football field

When tens of thousands of football fans fill Studenternas arena in Uppsala, few realise that the stadium’s sanitation system is quietly modelling the future of urban sustainability. Behind the scenes, the Swedish urine recycling company Sanitation360, together with the Swedish University of Agricultural Sciences (SLU) and the City of Uppsala, has installed one of Europe’s first and largest urine collection and treatment systems.

Sanitation360’s urine recycling installation, supported by the CiNURGi Project, demonstrates how cities can recycle urine at public venues and how urine-diverting toilets and urinals are becoming the new normal in the process of creating a more circular society. This initiative addresses two long-standing challenges of modern sanitation — managing hydraulic and nutrient peak loads during large events, and turning what is traditionally viewed as waste into a valuable agricultural resource.

Managing peaks

Large arenas experience extreme fluctuations in wastewater flow. During matches or concerts, thousands of toilet visits occur within short periods, creating significant hydraulic surges and nutrient shocks for municipal wastewater treatment plants. These peaks force utilities to maintain excess treatment capacity and operate with high energy demand, even though such high loads occur only occasionally. If a wastewater treatment plant does not have this extra capacity, then untreated wastewater is released into our waterways, exacerbating eutrophication and overall water pollution.

At Studenternas, urine is diverted and collected before it reaches the conventional sewer network. As urine is the most nutrient rich fraction we excrete, each visit to the urine-diverting toilets or urinals removes the most nutrient-dense fraction from the wastewater flow. With an average attendance of around 7,000 people at Studenternas, the installed system collects the equivalent of about 1,050 kg of fertiliser every year, enough to fertilise three football fields every year.

Controlling odours

The collected urine is stabilised with an eco-friendly, food grade stabiliser. On-site stabilisation of urine is crucial both for retaining its valuable nutrients and for controlling odours. Without the stabilisation, the most sought after nutrient in our urine, nitrogen, escapes as a gas, producing the unpleasant smells commonly associated with urinals and festival toilets. This source-separation approach captures a concentrated stream of nitrogen, phosphorus, and potassium — nutrients essential for food production yet often lost in conventional treatment systems.

Circular potential

The stabilised urine is concentrated on site to reduce the volumes, and subsequently transported to Gotland, where Sanitation360 processes it into a solid fertiliser product known as Granurin. The concentration process reduces the mass of the original urine by a factor of roughly 25 while retaining all its nitrogen, phosphorus, potassium and micronutrients.

Granurin is a clean, safe product that replaces synthetic fertilisers and offers a regional source of nutrients at a time when global supplies are becoming less predictable. Reducing the need for synthetic fertilizers helps shrink one of the world’s most polluting industries, as synthetic fertilizer production generates more emissions than global aviation and shipping combined. The Studenternas installation demonstrates a local example of nutrient circularity where valuable nutrients are reintroduced into the food production cycle.

The Studenternas installation is a permanent, full-scale demonstration within a public facility. It provides valuable data that can not be collected in a laboratory or from a temporary pilot test. The data helps us understand how people behave when using urine-diverting toilets in a high-traffic setting, how the drying technology performs over time, and what the operating costs look like under real conditions.

This case illustrates that circular nutrient management can be integrated into existing infrastructure without compromising user comfort or hygiene. It also highlights the importance of collaboration between municipalities, academia, and private companies in turning conceptual sustainability goals into practical solutions.

Towards scalable circular sanitation

Urine-diverting sanitation systems alleviate pressure on urban wastewater systems while recovering nutrients that would otherwise be lost and released into the environment as pollutants. Scaling up such initiatives will help cities meet multiple policy targets simultaneously, such as, reducing nutrient emissions to waterways, lowering reliance on fossil fuel-based fertiliser production, and advancing a circular bioeconomy. Sanitation360 installation provides a tangible model for rethinking sanitation as a service that not only protects public health but also regenerates natural systems. At Studenternas, every matchday now contributes — quite literally — to growing the future.