SLU’s Urine Drying in Deutsche Welle (DW)


Beatrice Christofaro captures the argument quite well as to why source-separated fractions like #urine should be recycled in this #DeutscheWelle (DW) article.

The way we manage nutrients in our wastewater and produce food globally is not sustainable. Countries are vulnerable changes in supply of fertilizers, as they’re produced using non-renewable feedstock such as natural gas, coal, and phosphate rock. Majority of the fertilisers used globally are also produced by a handful of countries. So its not a big suprise to us that fertiliser prices have soared recently and food price inflation has increased.
But we can make food production more resilient. Read the article and see how the #SLU and #Sanitation360 solution could increase local food security.

Read Full Article here:

New publication digs deep into dissolution behaviour of Magnesium Hydroxide in Human Urine


Here’s a new paper we published in Frontiers in Environmental Science:

In the study, we systematically analysed the kinetics and thermodynamics of how magnesium hydroxide dissolves in different types of human urine (fresh urine and fresh urine concentrated by evaporation). We showed that Mg hydroxide has a unique dissolution behaviour which is unlike that of other alkaline earth hydroxides, especially when water is removed from urine. We detail conditions and design criteria for alkalising and for dehydrating urine, which is useful when developing source-separating sanitation systems.

A cool aspect of the study was that we found a smart way to simulate the kinetics of how fast Mg hydroxide dissolves, how fast various precipitates form (e.g. struvite, apatite), and how fast urine is alkalised and saturated. We did this by matching the experimentally measured pH of urine with its thermodynamically simulated pH. This approach could be applied to any system as long as the parameter we measure is something we can also simulate thermodynamically.

Can urine help save food production under crises?


Field with crops. Two persons in the background.

Prithvi spoke with Agnes Bondesson, SLU Global’s International Scientific Communications Officer about the ongoing food and fertiliser price inflation. Check out the article here: or read below –

With the current state in the world, seen to conflicts and climate change, the question about food production in case of short-term or long-term crises has been emphasised. Sweden has a solid food production, but it is a production vulnerable for disruptions of imported products such as fertilisers, diesel, pesticides, seeds and protein feed as well as electricity. One of the main components in conventional plant production is the use of imported fertilisers. When the climate crisis, higher prices and insecurity in import forces us to rethink our ways to use artificial fertilisers there is a need to see other solutions. 

Studyvisit to VAFAB in Västerås


We went on a study trip to the waste management company VAFAB in Västerås with students from our two courses about waste management, ”Safe nutrient recycling 15HP” and ”Waste management 5HP”. A very interesting tour that gave insights about the volumes of waste that we all generate, among the things we visited we had a bus tour over the 45 hectar old landfill. Additionally we had a nice tour of the newly re-built biogas plant and hear about the challenges they had with sediments in the reactors from egg shells, sand and dirt that consumes reactor volumes. The produced biogas is used for the local buses and the bio-fertiliser is collected by local farmers for free.

Food waste bags that have been collected in the Västerås region are stored before they are feed to the anaerobic digester.

Studiebesök på VAFAB i Västerås


Vi åkte förra veckan på studiebesök till avfallsbolaget VAFAB i Västerås med studenterna från våra två kurser som hanterar avfallshantering, ”Säker näring i kretslopp, 15HP” och ”Avfallshantering 5HP”. Det var en väldigt givande tur som gav tydlig insikt i mängderna avfall vi alla genererar, då vi bland annat åkte med bussen över den gamla deponin som är 45 hektar stor. Dessutom fick vi se den nyligen ombyggda biogasanläggningen och höra om problemen i biogasreaktorerna som orsakas av sediment från äggskal, jord och sand som tar upp en stor del av reaktorvolymen. Den producerade biogasen används till drivmedel, främst för stadens bussar, samt biogödseln som hämtas gratis av lokala bönder.

Matavfallspåsar som samlats in i Västerås regionen och väntar på att rötas.

Who cares about toilets?


Check out the article we wrote with SLU Global for World Toilet Day.

Today is World Toilet Day. According to WHO and UNICEF around four billion people in the world does not have access to a safely managed sanitation service. Untreated wastewater released to the environment can contaminate drinking-water sources, rivers, beaches and food crops, spreading deadly diseases among the wider population. This is rather unfortunate because source-separated wastewater fractions like human urine and faeces are renewable resources from which water, nutrients and energy can be recovered and safely recycled and used as a fertiliser. So SLU cares!

In the wastewater that comes out of a household, human urine makes up just 1% of total volume. However, in terms of nutrients, urine contains more than 80% of the nitrogen and over half of the potassium and the phosphorus. In fact, urine produced by people worldwide contains enough nutrients to fertilise three-quarters of the food we eat.

Earlier this year, Dr. Prithvi Simha from the Department of Energy and Technology at SLU, defended his thesis, which developed a novel on-site sanitation technology called “alkaline urine dehydration” to capture all the nutrients in urine without its water. Prithvi and his team at SLU are working to disrupt the way we manage wastewater and design sanitation systems. They believe that resources like urine should be separately collected, safely treated to produce fertilisers, and returned to farmland to close the nutrient loop in our food system. If implemented globally, such a system could reduce the transgression of the planetary boundary for nitrogen and phosphorus by 35% and 25%, respectively.

Studiebesök fran Kjell och Märta Beijers Stiftelse


Förra veckan välkomnade Cecilia Lalander från Kretsloppsteknik besökare från Kjell och Märta Beijers Stiftelsen på SLU Campus i Ultuna. I rampljuset var det senaste projekt “5 ton grön fisk i disk” (se blogginlägg från 4 mars ), där insektsmjöl tillverkades till fiskfoder på Campus Ultuna.

Besöket var ett utmärkt tillfälle att visa kretsloppsteknik-gruppens starka kompetens och relevans när det gäller cirkulär ekonomi (avfallshantering och foderproduktion). Efter ett snabbt besök skyndande gruppen vidare för att besöka andra forskargruppen och  få en inblick i den breda och viktiga forskning som bedrivs på SLU.

Kjell och Märta Beijers Stiftelse bildades 1974 genom en donation från Kjell och Märta Beijer. Utöver vetenskaplig forskning och utbildning stödjer stiftelsen kultur, framför allt med anknytning till svensk design och heminredningstradition. Stiftelsen står bland annat bakom Beijerinstitutet, ett av världens ledande forskningscentrum inom ekologisk ekonomi. Vilken bra dag det var och Cecilia fick många intressanta frågor och några av besökarna även provsmakade till och med våra torkade larver!

Studyvisit from Kjell och Märta Beijers Stiftelse


Cecilia Lalander from Kretsloppsteknik welcomed visitors from the Kjell and Märta Beijers Stiftelse at SLU campus in Ultuna. In the spotlight was the latest project “5 ton fish on the counter” (see blogpost from 04. March, where feed for trout was produced from insect meal at Campus Ultuna.

The visit was a great opportunity to show the group´s strong competences and relevance in regards of circular economy (wastemanagement and feed production). After a quick visit, the group hurried on to visit other research groups and get an insight to the wide and important research conducted at SLU.

The Kjell and Märta Beijer Foundation was founded in 1974 through a donation from Kjell and Märta Beijer. In addition to scientific research and education, the foundation supports culture, above all in connection with Swedish design and home furnishing tradition. Among other things, the foundation is behind the Beijer Institute, one of the world’s leading research centers in ecological economics. It had been a great day and Cecilia received a lot of interesting questions and also witnessed some of the visitors testing our dried larvae first hand!

Our BSF project “5 ton grön fisk i disk” featured in Dagens nyheter


Från februari till maj 2021 producerade projektet “5 ton grön fisk i disk” (delfinansierat av Vinnova) 1,7 ton larvar på en blandning av 10 ton grönsaks- och brödavfall. Grönsakerna kom från  Sorunda Grönsakshallen medan brödet var återtaget bröd från Fazer . Larverna producerades inte bara på SLU campus utan blev även vidareförädlade här: efter torkning vid 60°C i 48 timmar pressades den torra larvar i en skruvpress för att separera från proteinet från fettet. Det avfettade proteinmjölet förvandlades sedan till fiskfoder till regnbågslax, som föddes upp av Älvdalslax i Dalarna.

Behandlingsresten, det så kallade frasset, användes som jordförbättring på en närliggande studentledd permakulturodling.


Dagens nyheter hörde talas om projektet och kom och besökte oss. Jessica Ritzen följde Cecilia Lalander och Anders Kiessling genom de olika stadierna av proteinproduktionen till fem-ton-fisk-i-disk projektet. Följ länken för att läsa hela artikeln här.