Author: Prithvi Simha

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.

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.

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.

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.