The CLONIC ‘Closing the Nitrogen Cycle from Urban Landfill Leachate by Biological Nitrogen Removal over Nitrite and Thermal Treatment’ project is focused on nitrogen removal through the application of two biological processes: a partial nitritation of ammonia followed by an anaerobic ammonium oxidation (anammox). Finally, a thermal dry treatment closes the cycle. This CLONIC project workshop will present final results and will give researchers the opportunity to share their experiences in the field of nitrogen removal