Sustainable recovery of phosphate
In wastewater or in digestate, large amounts of phosphorus can be present. With stringent phosphorus discharge limits below 2 mg/L it is crucial to remove this nutrient in the most sustainable way. Colsen offers a solution for that with its ANPHOS® technology. This technology focuses on recovery of phosphorus rather than removal of phosphorus. Specifically phosphorus is recovered as struvite (magnesium ammonium phosphate) which is applied as phosphate fertilizer or as substitute for the depleted phosphate ore.
The sustainable way of recovering phosphorus with the ANPHOS® technology leads to an improved business model of wastewater or digestate treatment plants reducing operational costs and closing the phosphorus nutrient cycle.
ANPHOS® is mainly applied on wastewater streams with at least 50 mg P/L or higher for example in potato processing industries, sidestream treatments of municipal STP or in digestate treatments.
An ANPHOS system is a two-step batch system. In the first part of the system wastewater is in an aerated stripping tank to introduce a positive pH shift. This stripping tank is aerated by a low maintenance aeration system.
Secondly, magnesium is dosed in a reaction tank, where reacts with the present phosphorus (as phosphate) and ammonium forming struvite. After this precipitation phase, struvite is settled, discharged, and dewatered. The formed product is readily accessible as substitute for agricultural fertilizers or as a phosphate ore.
AN PHOS® induces a total operational cost reduction of 60 to 70% compared to conventional dephosphatation due to:
Reduction in chemical costs
Reduction of sludge production
Reduction of ammonium load on subsequent treatment system
Production of struvite