Tag: Source-separating sanitation systems

We have recently published a paper in Resources, Conservation and Recycling which looks into the possibility of using Poly-L-Lactic Acid (PLLA) biopolymer to capsulate and safely dose chemicals to human urine.

Alkaline dehydration of urine for recycling of plant essential nutrients requires fresh urine to be stabilized with alkali or metal hydroxides. Improper handling and exposure to these chemicals may cause skin or breathing irritation. Therefore, if these chemicals are wrapped inside capsules made of a biopolymer, human interaction with these chemicals can be minimized and chemicals could be passively dosed to urine. These capsules can also be used for dosing of oxidants and peroxides for the removal of micropollutants and pharmaceuticals from urine.

In the study, degradation of PLLA films in Ca(OH)₂ dosed fresh urine was evaluated with temperature, thickness and pH being the variables. The results of this investigation provided some really interesting results in terms of physiochemical changes in the urine and the physical, chemical and molecular changes of the films. If you are interested to find out more and read the full article, click here: https://www.sciencedirect.com/science/article/pii/S0921344923003361 .

The flagship report of the UN Environment Programme (#UNEP) and Global Wastewater Initiative (#GWWI) was recently released at the #WorldWaterWeek in Stockholm a few days ago! Prithvi Simha from the group contributed to the report as one of the authors.

This new report, “Wastewater – Turning problem to solution” urges decision makers and action takers from all regions of the world to implement the three key actions, to overcome some or all seven barriers, and to put in place all or some of the six building blocks, described in the publication.

The report features SLU – Swedish University of Agricultural Sciences and Sanitation360 AB‘s work on #urine #recycling in the form of three case studies:
1. Producing urine-based fertilizer on the island of Gotland, Sweden (work from our #N2brew and P2GreeN #EUH2020 projects)
2. Urine separation – Alkaline dehydration in practice in #Malmö, Sweden (work from our REWAISE EU project)
3. Social barriers to urine recycling in decentralized sanitation systems.

Hi, my name is Jacob Fager. I’m stationed on Gotland and my main task is to collect urine. I used to be a soldier since I finished school 2016 but now I’m about to study to become a farmer. I grew up on my family’s farm, so it has always been in my interest. While I’m waiting on my studies to start I will be helping this interesting project and hoping I will lucky to be able to use human urine fertilizer on my future farm.

Ya Gao comes from China and previously received her Master’s degree in Environmental Technology at Wageningen University and Research in the Netherlands and her Bachelor’s degree in Environmental Sciences at Tongji University in China. After the graduation from her previous study, Ya Gao worked in a green building sustainable consultancy company in Shanghai as a project engineer for one and a half years. In May 2023, Ya Gao has joined the Kretsloppsteknik group as a PhD student working for the EU project P2Green. The main focus for her PhD study will be the urine dehydration research that aims at dehydrating the acid-stabilized human urine and recovering the nutrients contained in the urine for the use of plant fertilizers.

Sanitation360 (spin-off company from our urine drying group at Kretsloppsteknik, SLU) has been awarded the Innovative Startups Step 2 by Vinnova. During 2021-2022, Sanitation360 used the funds from Step 1 to assess the market potential for manufacturing and selling the urine-drying technology in South Africa. During that time, S360 found the partners perfect partners – Scandinavian Water and Sanitation and Sanitation Ambassadors. Together, they will design, build and implement the drying system in South Africa. The generated fertilizer will also be used. The project runs from now till May 2024. Stay tuned for more up-dates.

More about the funding: Companies that have further need for financing after Innovative Startups step 1, finalized a project in step 1, can apply for funding in step 2. In step 2, Vinnova can contribute up to 90 % of the project budget, up to a maximum of 900,000 SEK. More information about the Vinnova funding can be found here: https://www.vinnova.se/en/calls-for-proposals/innovative-startups/

In the latest article published in Science of the Total Environment (STOTEN), Prithvi Simha and Dyllon Randall from the group along with colleagues (Chibambila Simbeye, Caitlin Courtney, and Nico Fischer) show for the first time that we can produce vivianite from human urine. For those who don’t know, vivianite is iron phosphate ((Fe(II)₃(PO₄)₃·8H₂O) and is in high demand in the electronics industry for lithium-ion battery production as well as in the art industry as a pigment in paint. It can be sold for as much as $100-500 per kg. Considering that struvite and calcium phosphate can typically only be sold for $1 kg⁻¹, recovering P as vivianite would likely be significantly more profitable.

In this work we determined ideal operating regions for vivianite production from human urine. We showed that overdosing iron exerted a competitive effect that suppressed the precipitation of other precipitates and could also compensate for changing urine compositions. Overall, the highest yield and purity was 93% and 79% respectively. We showed that the presence of organics in real urine ultimately affected the purity. Thank you to the Water Research Commission for funding this work and to the SLU – Swedish University of Agricultural Sciences‘s August T Larsson Guest Research program for Dyllon’s current research visit to SLU.

About a month ago now, Sanitation360 finally started this year’s field trials where barley is being grown and fertilized with human urine. In addition, this is an extra special year because we’re not only trialing our dry-fertilizer but liquid urine too (see top photo)! It’s going to be really interesting to compare the barley yields between these two different forms of human urine.

In the two photos you can see Hushållningssällskapet Gotland, our local agricultural consultancy partners, using a seed drill to plant the barley and the solid urine fertilizer! Can’t wait to share the results!

We are extremely happy to share our latest milestone – something that we set as a aim almost ten years ago – to produce a dry urine fertiliser with the same nutrient content as that of synthetic fertilisers so that we can replace their use in agricultural systems. Earlier this year, we managed to produce the first 20 kg batch of our solid urine based fertiliser, Granurin, with >15% nitrogen content. The urine was collected last year from public urinals on Gotland as part of the N2Brew project, and treated by Sanitation360 AB, with final processing and fertiliser pelletisation done at SLU – Swedish University of Agricultural Sciences by Bjorn, Jenna and Prithvi.