SLU Kretsloppsteknikn hosts Wageningen’s ETE department


Several members and PhD students of the ETE department (Environmental Technology) at Wageningen University & Research visited SLU earlier this month. We enjoted several interesting presentations from Miriam van Eekert, Huub Rijnaarts, Cecilia Lalander and Prithvi Simha which were followed by great discussions and a poster session where all PhD students got to showcase their research. We all also got to play a serious game which was facilitated by Jennifer McConville. It was a great day and we really look forward to future collaboration with ETE.

Hybrid PhD course on Safe nutrient recycling and management


We at Kretsloppsteknik are currently giving a hybrid (onsite/online) course on Safe nutrient recycling and management (10 credit) within the
research school Sustainable systems for food, energy and biomaterials (SSFEB). The aim of the course is to give the student knowledge in current waste and wastewater management techniques, with focus on technologies for plant nutrient recovery and reuse. Today, 75% of all biodegradable solid waste is landfilled or dumped and 90% of all wastewater generated is either not treated or only partially treated. In cases when the waste is treated, treatments are not focused on recycling, but rather removal, of plant nutrients, as they can otherwise risk to pollute the environment. If the plant nutrients in the waste and wastewater were collected they could replace 25-50% of the virgin resources used for production of chemical fertilizers used in agriculture. Looking at waste and wastewater as resources is a paradigm shift, and for this shift to happen new technologies and management systems are required. When closing the loop of nutrients there is a risk of recycling unwanted substances as well, e.g. heavy metals and pathogens. Upon completion of the course the student should know the flow of waste and wastewater in society, possible treatment methods for closing the loop of nutrients and the risks associated with closed loop systems, as well as methods for mitigating circulation of unwanted substances.


Picture from our last seminar, with two participants being onsite and four participants joining online from India, China and Rwanda.

Knowledge evolution within human urine recycling technological innovation system (TIS): Focus on technologies for recovering plant-essential nutrients


”Knowledge development and diffusion” is a key function in developing technological innovation systems (TIS), especially early in the formative phase. If you are interested in knowing whether the current knowledge base on nutrient recovery technologies is sufficient to further develop urine recycling TISs, then this paper is for you:

We ( Robin Harder, Prithvi Simha, Bjorn Vinneras, Jennifer McConville and myself) conducted a bibliometric analysis and comprehensive mapping of existing urine recycling knowledge and used a novel multi-criteria framework to evaluate whether the development of such a TIS is feasible. Results showed that the rate of publications and knowledge diffusion increased sharply in 2011–2021 compared to 1990–2010. However, the function still has insufficiency in some criteria. … paper is attached.
Happy reading!

New Horizon Europe Project “P2Green” will pilot urine dehydration technology in Gotland!


A consortium of 32 partner organisations from 12 European countries and Switzerland including SLU and Sanitation360 have justed signed the Grant Agreement for a four-year Horizon Europe Project aiming to “close the gap between fork and farm for circular nutrient flows” short P2GreeN. From our group in Sweden, Jenna Senecal, Prithvi Simha, Jennifer McConville, and Björn Vinnerås will participate in the project. The project will start on the first of December 2022, and is coordinated by agrathaer GmbH and Leibniz Institute of Vegetable and Ornamental Crops (IGZ) e.V.

P2GreeN’s overall objective is to foster a circular material flow system between urban and rural areas thereby restoring the coupling of the water-agri-food system following the 3R principle “Reduce, Reuse, Recover”. To achieve this, P2GreeN will develop new solutions for the circular economy to halt and eliminate nitrogen (N) and phosphorus (P) pollution by connecting blue urban with green rural infrastructure, focussing on circular nutrient flows of nitrogen (N) and phosphorus (P), two important plant nutrients and at the same time water polluters. This objective will be achieved through the implementation and exploration of innovative N and P recovery solutions for the utilization of human sanitary waste from urban settlements and its conversion into safe bio-based fertilizers for agricultural production in three pilot regions.

We’re hiring! Two PhD student positions on development and assessment of next generation sanitation systems that recycle urine


Our group has two new positions for hiring PhD candidates –

PhD position in technology development of next generation sanitation systems. Link:

SLU has developed a new technology to treat source-separated human urine, where fresh human urine is chemically stabilised and then evaporated to produce water and a solid fertilizer. The technology has been piloted in several locations across Sweden (e.g., at the offices of VA Syd in Malmö). If implemented globally, human urine could substitute about one-quarter of current nitrogen and phosphorus fertilizers worldwide.

The aim of this PhD project will be to continue the technology development, with focus on performing research in support of scaling up the urine dehydrating sanitation system. During this project, lab-scale treatment systems available at SLU will be scaled up into full scale operations for the production of 25 kg of dry fertilisers per day. The project will involve both fundamental research (e.g., evaluating changes to composition and properties of urine during dehydration) and implementation research (e.g., developing reactors for stabilizing urine at the toilet). The PhD project will be part of a larger Horizon Europe Research and Innovation Action collaborative project, “P2Green” (Closing the gap between fork and farm for circular nutrient flows), where three pilot regions will scale-up and implement innovative sanitation technologies in real-life conditions. The Island of Gotland will be one of the pilot regions where SLU will scale up and validate urine dehydration. Contact: Bjorn Vinneras

PhD position in sustainable assessment of new sanitation systems. Link:

The aim of this project is to investigate the potential for new sanitation innovations to provide sustainable benefits by quantifying trade-offs in terms of environmental impacts, costs and uncertainties. The primary focus will be on developing decision-support tools that allow decision-makers to weight trade-offs and test options for integrating new sanitation systems into existing infrastructures. Methods used will include life cycle assessment, cost-benefit analysis and systems dynamic modeling. The assessment methods will be applied on case studies of emerging technologies for nutrient recovery from urine and wastewater in the context of an EU project. The work will include interaction with stakeholders to co-design of development trajectories for integrating new sanitation systems into the local context. Contact: Jennifer McConville

Nutrient stocks, flows and balances for the Bolivian agri-food system: Can recycling human excreta close the nutrient circularity gap?


Availability of nutrients from human excreta in Bolivia in 2018.

In our latest article in #Frontiers in Environmental Sciences, Luis Fernando Perez MercadoCesar Ariel Perez Mercado, Bjorn Vinneras and Prithvi Simha analyse the current state of nutrient stocks, flows, and balances of the agri-food system in #bolivia. Their findings show that there is sufficient stock of #nitrogen and #phosphorus in human excreta to meet the deficit of nutrients in the food system, as well as regional nutrient surpluses that are not recirculated today. Today, Bolivia recirculates 44% of nitrogen and 74% of phosphorus used in agriculture. But we believe that circularity is going to decrease considerably over the coming years, as the national strategy to address nutrient deficits has been to increase the domestic production of synthetic fertilisers (See

Calculating mass balances always seems simple on paper. But it is difficult in practice, especially when you perform it at national, regional, and municipal levels, as we have done in this article. They usually don’t add up. Here, they also suggest how deforestation and depletion of forest nutrient stocks could be a reason why our national-level balance does not add up.

The full artile is available here:

How to evaluate the effectiveness of game-based interventions in decision-making process?


In this latest publication on game-based approaches for planning and decision-making for sanitation, we have collaborated with researchers at EAWAG. The study aimed to answer the question: how effective are game-based interventions specifically designed to support decision-making processes? We used an illustrative case to reflect on this question. We simultaneously designed a card game to support sanitation decision-making and an evaluation procedure.

We found that it is possible to address the dual challenge of game-based interventions for participatory decision-making processes:

(1) designing an informative and engaging game-based intervention without telling participants what to think and

(2) designing a tailored evaluation procedure. Designing the game-based intervention and its evaluation simultaneously is valuable both to improve the quality of the game, but also the opportunity provided a structured assessment of the results.

We encourage others to follow this approach and use the evaluation framework proposed in this paper.




Abdulhamid Aliahmad’s one-year follow-up seminar


On the 20th of April, Abdulhamid (Abood) Aliahmad had his one-year follow-up seminar.The presentation focused on the findings of the first study and inputs from the second study.

The first study focuses on evaluating whether the current state of knowledge concerning urine recycling technologies is sufficient to facilitate upscaling development and increased diffusion. Knowledge development and diffusion is a key function in the development of technological innovation systems (TIS). The study proposes a multi-criteria framework, together with bibliometric analysis to conduct such evaluation. The second study will follow up on this one examining other functions of the TIS.

He preliminary concluded that urine recycling TIS has the tendency for strong publication rate growth and diffusion between countries. However, the function still has insufficiency in some criteria. The analysis identified the lack of innovation in scientific research and the lack of diversification of emerging technologies into the TIS as weak elements. The frequency of research publication and pilot-scale implementations on each technology shall be higher.

He also included the proposed approaches for his next two studies. The seminar ended with many interesting questions and discussions.

If you want to know more about his research, click here.

Possibilities for changing to resource recovery in Kampala’s on-site sanitation regime



We are proud to share a recently published study from the SPANS project related to opportunities for introducing resource recovery innovations in Uganda. In particular we look at the four source-separating on-site sanitation systems – niches. The study was performed in collaboration with Makerere University and RISE. It uses the multi-level perspectives of socio-technical systems to deepen our  understand the existing situation (regime). Through this in-depth analysis of current practices in the Ugandan sanitation sector, we have been able to highlight stress points that could be used to leverage a change to new systems and ways of doing things. Stakeholder specific suggestions for action based on results of this study include:

  • Utilities should pilot innovative solutions in order to demonstrate their advantages and build knowledge.
  • Universities should adapt curricula to break the dominance of sewage systems, including more on-site solutions and Best Available Technology (BAT) approach to selection of systems.
  • Researchers should disseminate knowledge regarding technical advantages of the niches.
  • Niches should focus on possibilities for simplifying organisational structures, streamlining and clarifying roles and responsibilities.
  • Policy makers should adapt policy environments to reflect actual and planned reality of sanitation services, including making public funding available for the on-site regime and its niches.


For more information contact Jennifer McConville.

China should focus beyond access to toilets to tap into the full potential of its Rural Toilet Revolution


Check out our latest article, a collaboration with the Zifu Li group at USTB Beijing that was published in the journal Resources, Conservation and Recycling:

Zhou, X., Simha, P., Perez-Mercado, L. F., Barton, M. A., Lyu, Y., Guo, S., … & Li, Z. (2022). China should focus beyond access to toilets to tap into the full potential of its Rural Toilet RevolutionResources, Conservation and Recycling, 178, 106100.

Abstract: In China, over 47 million toilets in rural areas have been upgraded since the nationwide sanitation program, popularly referred to as the “toilet revolution”, was launched in 2015. However, little is known about the perceptions of rural households regarding these new toilets or the fate of human excreta collected using them. To investigate the other side of the toilet revolution, we surveyed 980 rural households from 22 provinces across China in 2020. We found that most households used an on-site sanitation system (i.e. septic tanks and pit latrines), where urine and feces were mixed and collected (88%), stored in pits or tanks (79%), emptied by the households themselves (60%), applied on farmland as fertilizer (45%), or used for biogas production (5%). Despite the toilet revolution-driven infrastructure upgrade, only 25% of the households were satisfied with their sanitation system and pointed to health risks from issues in the toilet interface and the treatment and reuse of excreta as areas of concern. The majority preferred an “out of sight, out of mind” approach, in which the local government handles excreta without involving the households and without asking them to pay for such management. Meanwhile, 80% supported the idea of local nutrient recycling and believed that human excreta should return to farmland as fertilizer or used for biogas production. Our findings suggest that decision makers in local governments across China must urgently explore ways to upgrade all parts of the sanitation service chain so that rural sanitation can be truly improved to positively influence the progress on other national sustainability goals.