All posts by Prithvi Simha

Guide to Sanitation Resource Recovery Products & Technologies published!

We are very pleased to share with you the 1st edition of the Guide to Sanitation Resource Recovery Products & Technologies. The Guide is a popular science publication that gives an overview of the possible resources that can be recovered and provides guidance on treatment processes to achieve safe products for reuse. The specific objectives of this document are:

  1. To expose the user to a broad range of recovered sanitation products and innovative treatment technologies.
  2. To help the user to design functional solutions for resource recovery by illustrating the linkages between sanitation inputs, treatment technology and the recoverable products.
  3. To provide an overview of basic information regarding design aspects, operational requirements, and health, safety and social considerations related to resource recovery technologies and products.
  4. Describe and fairly present technology-specific advantages and disadvantages.

The Guide to Sanitation Resource Recovery Products and Technologies is primarily a reference book. It is intended to be used by engineers, planners, end-users, researchers, technology developers, sanitation entrepreneurs, non-governmental organisation (NGO) staff and students who are interested in creating circular systems for resource use. It aims to support and enable decision making for increased resource recovery by providing information on key decision criteria for a range of recovered products and treatment technologies, thus highlighting the diversity of options available for resource recovery.

Links to download the guide:

Continue reading Guide to Sanitation Resource Recovery Products & Technologies published!

Chris Buckley talks to Radio SAfm about urine drying

Last week, following our joint article on urine recycling in The Conversation Africa, Prof. Christopher Buckley from the University of KwZulu-Natal was interviewed by SAfm, South Africa’s national public radio station. In his interview with Stephen Groote, Prof. Buckley talked about our group’s pioneering urine treatment technology, alkaline dehydration, and how the technology holds promise for implementation across Africa. In the coming year, along with Prof Buckley’s research group and local stakeholders, we are hoping to implement our urine drying technology in Durban, South Africa. Listen to the interview below –

Studiebesök med masterstudenter på Hållbara livsmedelssystem

I september månad tog kretsloppsgruppen emot ett studiebesök från masterstudenter på programmet Hållbara livsmedelssystem. I kursen Prospects and challanges for sustainable food systems, som hålls av Pernilla Tidåker, universitetslektor vid institutionen för energi och teknik, ingår ett par föreläsningar om källsorterande avloppssystem och återvinning av näringsämnen och i dessa föreläsningar bakades studiebesöket in.

Victoria Wiklicky, forskningsassistent, gav en introduktion till fluglarvskompostering, Caroline Karlsson, också forskningsassistent, pratade om källsorterande avloppssystem och urintorkning och Annika Nordin, forskare, visade och berättade om kretsloppsgruppens innovativa avloppslösningar.

Studiebesöket hölls utomhus i linje med covid-19-restriktionerna. Studenterna fick cirkulera mellan de tre stationerna, lyssna och diskutera de olika forskningsområdena. De fick även (med avstånd) följa med upp och titta på Energi och tekniks urinsorterande toalett och urintork.

Study visit from Sustainable Food Systems

In September, the environmental engineering group received a study visit from students in the Sustainable Food Systems master program. The course Prospects and challenges for sustainable food systems, held by Pernilla Tidåker who is a senior lecturer at the Department of Energy and Technology, includes a couple of lectures on source separation of waste water and the concept of nutrient recycling. Victoria Wiklicky, research assistant, gave an introduction to fly larvae composting; Caroline Karlsson, also research assistant, talked about source-separation of waste water and urine drying and Annika Nordin, researcher, showed and talked about the environmental engineering group’s innovative waste water treatment solutions. The study visit was held outdoors in accordance with the covid-19 restrictions, the students circulated between the three stations, listened to and discussed the different research topics. They also got to pay a visit (at safe distance) to the urine diverting toilet and drying system at the department of Energy and Technology.

We developed a simple process to recycle urine. Here’s how it’s done in 10 Steps

Every year on November 19, the United Nations celebrates one of public health’s greatest inventions – the toilet. Those who are fortunate enough to have access to one spend more than a year of their lives on it, yet millions of people worldwide cannot use one and many have never even seen one.

Invented back in 1775, the flush toilet has changed surprisingly little in design. In fact, a toilet is nothing more than a seat (or a pan) connected to a pipe with a bend. If this pipe is further connected to a system of sewers that carries away excreta to a centralised treatment plant, then wastewater can safely be discharged into the environment.

Continue reading We developed a simple process to recycle urine. Here’s how it’s done in 10 Steps

Prithvi Simha speaks to SAfm radio station in South Africa about urine drying

This week, following our article on urine recycling in The Conversation UK, Prithvi Simha from the group was invited for a live radio broadcast by SAfm, South Africa’s national public radio station, operated by the South African Broadcasting Corporation. The show is called Late Night Conversation with Patricia Ntuli. During the 30 minute interview, Prithvi and Patricia spoke about a range of topics surrounding urine recycling, and how urine can be dried using the group’s revolutionary invention, alkaline dehydration. Listen to it below –

Science/Environmental Conversations: We found a way to turn urine into solid fertiliser

Olof Sundström to work with plant growth trials with several organic fertilizers

Hello! My name is Olof Sundström and I just started working as a research assistant at the Environmental Engineering group. I graduated as a Soil/Crop Agronomist this June and I have been looking forward to start working. Stockholm is my hometown but most of my family is from the greater Uppsala area. My interest for agriculture and nature have always been strong, which explains the choice of education. The areas in agriculture that I am most interested in are plant pathology and plant nutrition. While here, I will be working with a greenhouse experiment. The purpose of the experiment is to examine the value of several organic fertilizers on basil and westerwold ryegrass. Even though my time here will be brief, I am happy to be a part of the team.

REWAISE – the new EU H2020 project piloting urine drying in Malmö

The 5-year European H2020 Project REWAISE has just started, involving 24 partners from 11 different European countries, and is led by Aqualia. It aims to shift the paradigm from a linear to a circular, water smart economy. As a part of this project, SLU-Kretsloppsteknik is a linked third partner with the aim to build and install its revolutionary sanitation technology, alkaline urine dehydration, in the Swedish city of Malmo. On the SLU side, we will work primarily with VA SYD, Sweden Water Research and Malmo Stad.

We will do this by working together with Sanitation360, our spin-off company commercialising the technology and EOOS Next, an Austrian design firm that will help design a new prototype that brings us closer to real-life implementation. Already over the past few months, SLU, S360 and EOOS Next have been intensively building and testing the prototype, which has now left Vienna and is on its way to us in Uppsala. After more testing at SLU, this module will be installed along with Laufen’s exciting new urine-diverting toilet called Save! at a toilet inside the office headquarters of the VA SYD wastewater treatment plant.

Continue reading REWAISE – the new EU H2020 project piloting urine drying in Malmö

We found a way to turn urine into solid fertiliser – it could make farming more sustainable


It’s likely that most of the food you’ll eat today was not farmed sustainably.

The global system of food production is the largest human influence on the planet’s natural cycles of nitrogen and phosphorus. How much crops can grow is limited by the amount of these two elements in the soil, so they’re applied as fertilisers. But the majority of fertilisers are either made by converting nitrogen in the air to ammonia, which alone consumes 2% of the world’s energy and relies heavily on fossil fuels, or by mining finite resources, like phosphate rock.

But a solution to this problem could be much closer than people realise. Most of the nutrients we consume in food are passed in our urine, because our bodies already have enough. But instead of being recaptured, these nutrients are flushed, diluted, and sent to wastewater treatment plants where they’re scrubbed out, leaving effluents that can be safely released into the environment.

The most nutrient-rich part of wastewater is human urine, which makes up less than 1% of the total volume but contains 80% of the nitrogen and 50% of the phosphorus. We discovered how to recycle this urine into valuable – and sustainable – farmland fertiliser.

Continue reading We found a way to turn urine into solid fertiliser – it could make farming more sustainable