The electrochemical battery – a new key for recovering urine nutrients at source

From 2012 to 2016, seven European partners, including the Luxembourg Institute of Science and Technology (LIST), devoted their efforts to the development of an innovative bioelectrochemical system with the potential to recover more than 95% of the phosphorus and nitrogen contained in urine. Their objective? To recover these nutrients, which are indispensable for the agricultural industry, without drawing on natural resources, and thereby minimise the energy impact and the use of chemical products linked to their current use. 

A new technology was developed during the project and is currently at the prototype stage. Its main innovation, which involves using an electrochemical battery at the very moment when the elements of urine are separated, has thus proved its effectiveness. 

Impacts and acceptance analysed by LIST 

As part of the ValueFromUrine project, LIST experts contributed their expertise in terms of assessing the durability of the project, which involved modelling impacts and developing scenarios, all of which was done in accordance with the principles of Life Cycle Analysis (LCA). As well as producing a medium-scale and large-scale assessment of the environmental and economic impacts of the project, they also carried out an acceptance study to validate its acceptability to the stakeholders affected by an innovation of this kind. Water managers, water treatment technology suppliers, fertiliser suppliers, town planners and agriculturalists from Luxembourg and the Netherlands were asked to give their views. 

From an environmental perspective, it is indisputable that the technology developed in the project makes it possible to reduce the production of chemical fertilisers because of its proven ability to recover the nutrients in urine; that it reduces the energy consumption of purification plants because the urine is treated in advance; and that it saves water because the technology requires the use of separating toilets which operate without water. Incidentally, this last point ties in with the main economic benefit noted in the project. As for the stakeholders affected by ValueFromUrine, they stressed the value of the process developed in the project, but downplayed its economic viability, which is still difficult to predict at the present time. 

And tomorrow? 

Thanks to the promising results obtained from ValueFromUrine, further development of the technology, though still far from market-ready, should be envisaged. In order to achieve this, new research and development projects will be necessary in future. 

As for LIST, both its involvement and the analyses it carried out within the framework of the project enabled it to develop new modules for modelling the impacts of wastewater treatment technologies. It may find these modules useful for future research projects relating to purification plants. 

>> To find out more about the project, visit ValueFromUrine webpage.