Phosphorus recovery as struvite from digested sludge - experience from the full scale

There is an ongoing paradigm shift; wastewater is often not considered a waste any more, but a source of valuable resources: nutrients (N: nitrogen, P: phosphorus, and K: potassium), energy and water. The recovery of phosphorus from municipal wastewater has gained a lot of attention because of limited phosphate rock reserves and associated geopolitics, and pollution of phosphate rock. At the WWTP of Leuven, Aquafin operates a full scale installation to recover phosphorus as struvite from digested sludge. This paper discusses the performance of the struvite plant, pollutants in the struvite, struvite use, and economics.