Production of Struvite from Manure and Digestate

Struvite, a magnesium ammonium phosphate fertilizer, is produced from agricultural byproducts like manure and digestate through nutrient recovery. The process involves acidifying slurry or digestate to mineralize organic phosphorus, followed by microfiltration, magnesium addition, and pH adjustment to precipitate struvite crystals. Tested on a farm in Emilia Romagna, Italy, the method transforms nutrient-rich waste into a stable, slow-release fertilizer suitable for agricultural use. After drying and granulation, the resulting struvite enhances marketability and application efficiency. This technology addresses nutrient surpluses in intensive livestock regions, reducing environmental issues such as water pollution and greenhouse gas emissions. By concentrating and stabilizing phosphorus and nitrogen, struvite enables transport to areas needing synthetic fertilizers, decreasing reliance on fossil-based inputs. The process improves nutrient use efficiency, lowers emissions of ammonia, methane, and nitrous oxide, and supports a circular nutrient economy. Farmers benefit economically by converting waste into a valuable product, improving soil health and reducing input costs. The approach aligns with sustainability goals and environmental protection by minimizing nutrient runoff and emissions.