The concept of a circular economy is gaining traction in many fields, although in certain sectors, the transition is complex and somewhat slow. One of the more complex sectors is nutrient reuse and recovery from wastewater. There are many challenges that must be overcome before this transition is successful. These include, but aren’t limited to, policy and regulations, public acceptance and economic factors. The complexity of the issue is immense and depending on factors such as wastewater treatment methods, catchment area, geographical context and soil health. The prices of energy, chemicals and fertilizers, regionally and world-wide, also play an important role. There is no ”one technology fits all” solution.
The Swedish Nutrient Platform plays a crucial role in the Swedish transition by engaging the entire value chain from wastewater to agriculture in discussions, projects, and conferences. This collaborative approach helps to bridge challenges and to develop innovative solutions for utilizing nutrients from wastewater in agriculture. The issue at hand is not isolated. Both the agricultural industry and the wastewater sector face numerous challenges. Circular nutrient management could help address challenges in both sectors. However, there is always a risk of new issues arising as new value chains are created. Concern about micropollutants and PFAS being top of the discussions today.
Achieving sustainable nutrient utilization from wastewater as introduced earlier involves navigating acceptance, technology, regulation, economics, infrastructure, and the need for new paradigms. Currently, agriculture is heavily dependent on mineral fertilizers produced mainly from fossil fuels and virgin materials. Nutrients in these fertilizers eventually end up in our food system and, after digestion, in our wastewater. By finding ways to recirculate these nutrients back into food production, we can reduce dependency on fossil fuels and virgin materials, helping agriculture to achieve climate neutrality. This approach also reduces the amount of reactive nutrients in the environment which mitigates eutrophication. Circular nutrients from wastewater could play an important role in future agriculture practices, but they cannot fully replace all the fertilizers currently used. If the fertilizing system continued to become more effective, with fewer losses and reduced needs, circular nutrients from wastewater, could be a significant source of nutrients.
While nutrient recovery from wastewater might seem like a minor issue, it involves many different stakeholders including food producers, water suppliers, industry, and urban wastewater managers. The stakeholders did not have a natural arena to meet and discuss these issues, which motivated the Swedish nutrient platform to take form. It also in ways includes the whole of society as consumers of food and the acceptance from them is crucial for nutrient recovery solutions to be successful. Nutrients from wastewater has potential to contribute to a more resilient food system, but the key question is how to create a product with market value from what is typically considered a waste product. The forerunners in nutrient recycling have taught us the importance of finding sustainable value chains and building long-term relationships with buyers of the product, as prices can be decreased —not because of product quality but because the product is produced continuously as a function of the 24-7 operation of wastewater treatment plants and potential customers know that storage space will soon enough be critical. Wastewater treatment plants typically aim to separate nutrients from incoming wastewater in order to prevent their release into receiving waters. This is core business for any urban wastewater manager. However, in some cases, the mission also includes making these nutrients available for reuse as fertilizers. In Germany, for example, the legislation requires the recovery of phosphorus from wastewater treatment sludge. In the revised ’urban wastewater treatment directive, phosphorus recovery will be mandatory across the European Union, but targets are yet to be decided. The revised directive also states that targets for nitrogen recovery are to be evaluated for future inclusion.
The Swedish Nutrient Platform, led by RISE Research institutes of Sweden and IVL Swedish Environmental Research Institute, focuses on raising awareness and bringing together a diverse range of stakeholders to work towards sustainable fertilizer production and nutrient reuse from wastewater. The platform serves as a knowledge hub, providing easily accessible information and facilitating collaboration among stakeholders to address issues and initiate new projects. The platform and its members are making plans for a circular future and finding ways to get there.
If you’re interested in the platform, please contact the project managers Elin Kusoffsky (elin.kusoffsky@ri.se) and Lisa Gren (lisa.gren@ivl.se).
Elin Kusoffsky
Project Manager, RISE Research Institutes of Sweden
Sweden
