Nutrient recovery

Sustainable fertilizer production—especially for phosphorus—will be a major challenge in the coming decades, making nutrient recovery from agricultural, urban, and industrial organic wastes increasingly important. This study evaluated five full-scale technologies used to recover nutrients from anaerobic digestate in farm-scale plants, including drying with acid capture, stripping with acid capture, and membrane-based separation. All systems achieved strong recovery performance, with average nitrogen and phosphorus yields exceeding 50%. The techno-economic analysis showed notable differences among the technologies: membranes produced high-quality water and reduced digestate volume, drying was limited by available heat, and stripping faced issues with suspended solids. Overall, the systems showed comparable costs, similar to those reported in other European applications, highlighting their practical feasibility.