Recirculating nutrients from human excreta back on to productive agricultural land will require a redesign of markets and, infrastructure, as well as policies and regulation. A diverse set of actors across the food chain, from grocery store shoppers and farmers, to sewage treatment plants, technology developers, and regulators need to have similar priorities and a concrete set of actions are needed in order to be able to work together towards these changes.
The ongoing global transition to a circular economy will require a revolution in how we manage human excreta. We need much more recycling in sanitation systems to reduce the release of nutrients into water and to ensure food security based on secure access to finite plant nutrients. Still progress towards sustainable management is slow. This is true in Sweden, as it is in many other countries, despite the presence of many innovators and some encouraging legislation (e.g., nutrient recovery targets). The Swedish Nutrient Platform (SNP), in collaboration with the End-of-Wastewater project, conducted a literature review, stakeholder surveys, interviews, and hosted a multi-stakeholder digital workshop (40 participants) as a step towards prioritizing actions to meet a common vision for nutrient recycling in Sweden by 2030.
Preliminary scoping activities indicated that in Sweden, as is the case in many places, there is disconnect between actors working in waste sectors and those working in farming, food, and agriculture, but that there is a desire to bridge this gap. One reason for this desire is that actors managing recycled nutrients want to produce products that match farmer needs. We summarized core factors and characteristics such products should have (Table 2) and used this list as a basis to prioritize characteristics with participating stakeholders. Workshop participants, which included both farmers and waste managers, also identified activities they saw as necessary to increase the use of these desirable recycled nutrient products by 2030.
Safety came out as a top priority when it comes to characteristics of products derived from human waste. Farmers, as its own subgroup emphasized the importance of knowing the nutrient content of products (nitrogen, phosphorus, and potassium) as a prerequisite for using it as a fertilizer, but thought safety was important, ranking it second. Participants confirmed that all of the product characteristic categories we had identified (Table 2) were indeed relevant, supporting our synthetic literature review. Although there was convergence about the importance of safety for many actors, it will be essential to engage with more farmers, and the food sector in general, to further direct certification and labeling on prioritized characteristics of products that match needs.
Participants named necessary actions in four focus areas:
• Regulations and policy
• Research to support decision making (implementation, benefits, costs, and risks)
• Infrastructure adaptation
• Knowledge sharing and collaboration
Although specific action ideas within each focus area were named, identifying who should be responsible for those actions was harder for people to answer. Bridging the gap in perspectives among types of actors is still needed and SNP can have a role in facilitating that process; There remains a need to determine specific intermediary actions with clear roles and responsibilities. It will be necessary to assign actors to specific roles. Some of these actions may focus on:
• Clear and supportive regulation at regional, national and EU levels,
• Certification systems for fertilizer products containing recycled nutrients from wastewater streams,
• Better knowledge sharing around risk mitigation and benefits of reuse,
• Sensitization of the general public, as well as actors who build sanitation infrastructure, and process and sell food, in and beyond Sweden.