Phosphorus Recycling

https://foodfeedfinechemicals.glatt.com/phos4green-pilot-plant-weimar/

Phosphorus is a plant nutrient that is essential for human nutrition. However, because natural deposits are limited, phosphorus recycling for sewage sludge will become mandatory from 2029. Glatt provides proven technology for this purpose – PHOS4green – which has been expanded to include heavy metal depletion as a crucial process step. PHOS4green is an innovative, patented process for recovering the essential nutrient phosphorus from ash, making it directly usable in the form of new phosphate or compound fertilizers through granulation. Acids are used to convert insoluble phosphates into a form that is bioavailable to plants. The conversion of the poorly soluble phosphate compound takes place in a suspension, the composition of which can be adjusted. The PHOS4green technology was implemented industrially several years ago. However, one widespread problem remained – that of elevated heavy metal content in sewage sludge and its ash. Without appropriate treatment, these phosphorus sources cannot be upcycled for use as fertilizer. However, Glatt now has a process for heavy metal depletion that has been successfully tested in a mobile demonstration plant. Here, experimental investigations into the redissolution and separation of heavy metals from sewage sludge ash can be carried out on a pilot scale.