Funding from the Kamprad Foundation will help address issues with mineral precipitation in urine collection systems


Håkan Jönsson and Prithvi Simha were very pleased to hear last week that the Kamprad Family Foundation decided to grant them #funding for a two-year project that will address issues with #precipitation of minerals in #sanitation systems that separately collect #urine. Together with Dyllon Randall (an August T Larsson Guest Researcher at Swedish University of Agricultural Sciences (SLU)), they will develop techniques for preventative maintenance/cleaning of toilets. They also plan to develop technologies that capture mineral precipitates at the toilet, thereby preventing their deposits along wastewater pipes. Much of the work in the project will be done in #collaboration with two housing associations in Stockholm, BRF Understenshöjden and BRF Gebers, where urine-separating toilets were installed more than 20 years ago!

Rich Earth Institute/Brightwater Tools visits SLU



Kim Nace and Ryan Homeyer of the Rich Earth Institute/Brightwater Tools visited Prithvi at SLU last month during their European tour of organizations that research and implement source-separation and nutrient recovery. They met over lunch and had discussions on a wide range of urine-related topics – how we collect urine, how we treat urine using our technologies (urine dehydration/SLU and freeze concentration/Rich Earth), our spin-off companies (Sanitation360 and Brightwater Tools), and how we operate in different contexts (Sweden versus the US; where regulations, funding and support are all different). But more importantly, the discussions really showed how similar our organisations are. For instance, our motivation with creating the spin-off companies are similar (to channel funding back to our research institutes rather than to make profit). It seems that organisations and people working with urine recycling could achieve more by joining hands and collaborating. So we really look forward to continuing the dialogue with the folks at Rich Earth Institute/Brightwater Tools.

Open position postdoctoral research fellow for studies on hygienisation in fly larvae composting


We are looking for a postdoctoral research fellow for our research in fly larvae composting, with a focus on the hygiene of the process as well as of the larvae and the treatment residue (frass-compost) from the treatment of society’s biodegradable waste. The work will be conducted in close collaboration with researchers and doctoral candidates in the group who work on related issues. The focus is to evaluate the degradation of various biological infectious agents such as bacteria (also spore-forming), bacteriophages and prions. The postdoctoral fellow is expected to pursue the following studies: 1) fate of prions in fly larvae composting; 2) fate of anaerobic spore-forming bacteria in fly larvae composting, and 3) study of mechanisms for killing salmonella in fly larvae composting.

Click here for more information.

Visit from CompoCloset founders to discuss urine treatment


The co-founders of CompoCloset, Erica Pugh and Richard Peter, visited SLU to discuss ways in which source-separated urine can be treated on-site. They have developed a composting toilet, Cuddy, that is specifically designed for vanlife that fits in small places like vans, tiny homes, cabins, and boats. They had nice discussions with Prithvi about ways in which SLU, Sanitation360 and CompoCloset could work together; e.g., by integrating SLU/S360’s urine dehydration technology with the Cuddy toilet.  

The Cuddy toilet. PC: Erica Pugh

Scaling up urine concentration technologies – what are the impacts?


There is a growing trend for nutrient recovery from wastewater as part of the transition to a circular economy. Most nutrients in household wastewater originate from urine and one way to facilitate reuse of these nutrients is to concentrate the urine into fertilizer products. Urine concentration technologies are still in the development phase and not implemented at scale. The aim of this study was to provide guidance to technology developers and policymakers by assessing the environmental and societal impacts of urine concentration technologies. In particular, it includes practical aspects such as worker safety, space availability and local fertilizer needs that have not been included in previous studies.

“Although many nutrient recovery technologies are not yet mature, it is good to evaluate them now. First to understand if they contribute to the sustainability that we want to achieve and then to identify improvement opportunities within the technology. It gives us guidance both for technology development and our strategic system planning.” says Jennifer McConville, one of the researchers behind the study.

Future scenarios on implementing three different urine concentration technologies (alkaline dehydration, nitrification-distillation, ion-exchange with struvite precipitation) in a planned residential area in Malmö, Sweden, were developed. The technologies were evaluated using multi-criteria assessment (MCA), with environment, technical, economic and health sustainability criteria derived from the Sustainable Development Goals (SDGs). It was found that all urine concentration technologies performed well against many of the sustainability criteria examined and can contribute to achieving SDGs, especially regarding nitrogen recovery. Specific areas for further development were identified for each technology. In particular:

  • Alkaline urine dehydration requires optimization of energy demand, to reduce the energy consumption and costs.
  • Nitrification-distillation requires optimization of the nitrification rate and matching it to the distillation capacity, which can reduce space requirements and costs. Attention should also be given to risk factors for workers.
  • Ion-exchange with struvite precipitation can be improved with respect to costs and risk for workers, in particular regarding use of sulphuric acid in regeneration of the ion-exchanger.

An impact assessment on scaling up demonstrated that nitrogen emissions to surface water were significantly reduced when more than 60% of urine in Malmö city was subjected to urine concentration. Nitrogen and phosphorus recovered from recycling only 15–30% of urine in Malmö could supply 50% of Malmö municipality’s fertilizer demand.

In the study, the researchers also tested the potential for more large-scale production of fertilizer through a scenario where the technology was scaled up to cover larger parts of Malmö. An up-scaling resulted in significantly lower emissions of nitrogen to the surrounding surface water and if 15 – 30% of the urine in Malmö is collected and concentrated, 50% of the municipality’s need for fertilization can be met.

Read the follow article here:

Gunnarsson, Matilda, Cecilia Lalander, and Jennifer R. McConville. “Estimating environmental and societal impacts from scaling up urine concentration technologies.Journal of Cleaner Production 382 (2023): 135194.

New study on acceptance of human excreta derived fertilizers in Swedish grocery stores


We have had several studies within the group looking at the acceptability of the use of fertilizers derived from human excreta. Most of them have focused on consumers or farmers. Acceptance among these groups is generally relatively high (or at least not low). Yet, a commonly cited barrier for use of these products is reluctance within the food industry. So we set out to fill this gap by targeting grocery stores in Sweden. The food retail sector, as an intermediary between producers and consumers, is an important actor with power to influence opinions and purchasing practices. In this study, we surveyed 127 food retailers (stores) and reviewed publicly available retailer sustainability policies to assess acceptance of the use of recycled fertilizers. We gauged acceptance of three products relevant for the Swedish market – struvite, phosphorus from ash, and dehydrated urine.

I key take-away from the survey was that food safety is a major concern for these actors. Acceptance of wastewater-derived fertilizers was largely dependent on perceived risks, especially the fate of pharmaceutical residues. Overall, most respondents felt that all three recovery techniques were unlikely to be harmful either to themselves or to the environment. It was more acceptable to use products further away from human consumption. In general, struvite and phosphorus from ash were perceived more positively than dehydrated urine. We speculate that this could be because of the word “urine” in the name or the fact that they are more worried about pharmaceuticals in the urine-derived product. While retailers in Sweden are not negative to reuse, they seem unlikely to provide strong support for nutrient recirculation from human excreta unless it becomes a greater concern for the public. So overall we do not see this sector as key drivers to support a transition to more circular nutrient use, but they are not likely to lobby against it either.

Read the whole paper here:

McConville, Jennifer R., Geneviève S. Metson, and Hugo Persson. “Acceptance of human excreta derived fertilizers in Swedish grocery stores.” City and Environment Interactions 17 (2023): 100096.

Jenna talks about urine on the Zuloo pōōdcast


Jenna Senecal was interviewed for the Zuloo pōōdcast. While they often talk about the number two, poop, they were eager to learn about how urine can be used as a fertilizer while also limiting our impact on the environment. Welcome to their pōōdcast where they bring insightful news, impact stories and quirky humor to the important topic of sanitation (or lack thereof). Listen to it here or on the youtube clip below –

New JTI-funded project on removing micropollutants from dried urine fertiliser


SLU has developed an innovative technology that converts human urine to high-quality solid fertiliser. On Gotland, we’ve also shown that urine can effectively fertilise barley, which can be processed further to produce beer. But there is concern about micropollutants that could be present in urine (e.g., pharmaceuticals). Through a three-year project and with funding from Stiftelsen Lantbruksforskning (Swedish farmers’ foundation for agricultural research), we aim to address this concern. First, we will do a baseline study to evaluate fate of micropollutants in the urine chain (fertiliser, barley & beer). Second, techniques will be developed to remove micropollutants so that only plant-essential nutrients are recycled back to farmland. Third, using social science methods and system dynamics modelling, support for recycling urine among food consumers will be assessed. Finally, all the evidence will be presented to stakeholders in the food industry.

Contact: Prithvi Simha

Final Policy Briefs from the SPANS project


In October 2022, the SPANS project had its final seminar in Kampala, Uganda. The five-year project financed by the Swedish Research Council aimed to improve knowledge related to adaptation and innovation in Sanitation Planning. In particular it explores technical and societal readiness of Alternative Nutrient-recovery Systems. The seminar highlighted the outputs of the project in terms of building knowledge on technologies for resource-recovery, understanding opportunities for implementing such systems and developing a serious game to promote safe resource recovery. All project results can be found on the website:

The team also used the seminar to launch the three policy briefs that have been developed in the project:

Abdullah Al-Saadi writing his thesis on fate of urine organics



My name is Abdullah Al-Saadi. I am originally from Iraq and I live in Finland. In Iraq, I have completed my bachelor degree in Chemical engineering. In Finland, I’m studying a Bachelor degree in Environmental engineering at the final stage. In SLU, I am doing my internship and Bachelor’s thesis project in urine treatment, which will focus on the fate of organic compounds in urine. I will work at SLU for the next 5 months.