Transforming wastewater into valuable resources
eLitre, a new EU-funded project, will develop technology to convert excess nitrogen pollutants in water into valuable products, such as ammonia and sustainable biopolymers.
Nitrogen is an essential nutrient for sustaining life on Earth, as plants and animals require it to synthesize amino acids, proteins and nucleic acids. Often, agricultural professionals use nitrogen fertilizers to boost crop growth and production. However, the overuse of these fertilizers saturates soils with nitrogen compounds, which leach into water streams and, together with industrial wastewater and urban sewage, accumulate in water and end up in our rivers and lakes. This excess of nitrogen in water causes eutrophication, damaging aquatic ecosystems and reducing water quality.
Today, nitrogen deposition exceeds critical loads in almost all European countries, and only 37% of Europe’s surface water bodies have good ecological status[1]. To address this challenge, the eLitre project aims to develop sustainable technologies to recover this nitrogen from wastewater and use it to produce valuable products such as ammonia and sustainable biopolymers.
Funded under the Water4All partnership with 1.1M€, eLitre will run over the next 3 years. The project brings together ICFO, the universities of Galway, TU Delft, and Lodz University of Technology, and the industrial partner Sorigué.
A two-step integrated approach
The project combines renewable energy with advanced electrochemical processes. “First, we selectively convert the nitrites and nitrates dissolved in the water into ammonia, using direct electrolysis”, explains Marcelo Chávez, postdoctoral researcher at ICFO’s CO2 Mitigation Accelerated by Photons group, directed by Prof Pelayo García de Arquer. “We then purify this ammonia so it can be reused, either as a fertilizer or as feedstock for other chemical processes”. Additionally, part of the recovered ammonia will also be used to optimize nutrient balances in photobioreactors, where microorganisms produce sustainable biopolymers.
Throughout the project, researchers will also evaluate the performance of each step of the process, measuring efficiency, energy consumption, and scalability indicators to identify the most promising route towards technological viability. By denitrifying water and recovering valuable resources, the technology will bring us closer to a more circular and resource-efficient economy.
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[1] European Environment Agency, June 2025: https://www.eea.europa.eu/en/topics/in-depth/water