In a world of dwindling resources and increasing pollution, waste management is a field of crucial importance. ‘Anaerobic digestion’, in which microorganisms break down biodegradable material in the absence of oxygen, is used to treat waste and sewage sludge. When integrated into a comprehensive waste management system, anaerobic digestion reduces the emission of landfill gases. The process is also widely used as a source of renewable energy, namely biogas. The EU-funded project ‘Efficient removal and recycling of nitrogen from organic waste as fertiliser’ (NIREC) sought to develop a sustainable method for recovering and recycling nutrients in waste through anaerobic digestion. In addition, the project converted residuals and by-products into marketable products. The project researched and developed laboratory-scale alternative technologies, including those relating to pre-treatment, the direct removal of nitrogen from the anaerobic digester, the refinement of the separation technology for dry solid and liquid residues with low organic matter, as well as the treatment of solid anaerobic residues to develop a marketable fertiliser product. This led to the establishment of several pilot plants to test the possibility of scaling up the different technologies. At its conclusion, NIREC – which was run by small and medium-sized enterprises (SMEs) for the benefit of SMEs – developed an integrated, ‘zero emissions’ solution using composted solid residuals and liquid residuals that could be recycled. The project also analysed the market potential, economic viability and legal status of the treated residues.