Only around 20% of the N entering the EU agricultural system is converted to finished products for human consumption. This result in large leakage of reactive nitrogen into the environment with negative impacts on soils, water and air, which are associated with health problems and environmental damage. Although nitrogen is a renewable resource, the industrial synthesis of nitrogen to ammonia is highly energy-intense (in the Haber-Bosch process) and releases significant amounts of greenhouse gases to the atmosphere. The industrial production of reactive nitrogen can be reduced by recovering nitrogen from waste streams as useful products to apply directly or indirectly (after further processing) as fertilizers. Flanders is designated as a nitrate vulnerable zone, which indicates the need for additional measure to protect and safeguard the environment. This highlights the need to increase nutrient usage efficiency through a more sustainable waste management system targeting the recovery and reuse of nutrients embedded in waste streams. Ammonium-rich liquid streams can be subjected to state-of-the-art stripping and acid scrubbing. Ammonia-rich gases or air with acid scrubbing. The extensive implementation of conventional stripping/scrubbing technology is prevented by several disadvantages: i) high operational costs, and ii) usage and storage of acids posing significant risks to human and environmental health. BioCatcher addresses these challenges as it aims to biologically and sustainably circumvent the use of scrubbing acids. In the project the operational boundaries will be explored and defined to understand the critical parameters. Secondly, a prototype reactor will be tested and optimised to overcome reach maximum concentrations of useful compounds. Finally, the economic viability will be evaluated.