Återvinning av fosfor från avloppsvatten och slam till produkter : slutrapport

The Swedish project P-to-Product focused on developing and adapting methods to promote recirculation of phosphorus (P) products extracted from sewage and sewage sludge. The project consisted of three work packages: 1) market introduction, 2) environmental impacts and 3) agricultural requirements. In wp 1 opportunities and barriers were identified and policy recommendations developed. This was done through interviews, surveys and workshops with stakeholders from sewage utilities, innovation companies, the fertilizer industry, the federation of Swedish farmers and national authorities. In wp 2 a simplified Life Cycle Assessment (LCA) was developed focused on nutrient recycling, global warming potential and energy use. In addition to this a chemical checkpoint was formulated with chemical analysis of a wide range of pollutants. For the development of methods in wp 2, granulated or pelleted nutrient products from the companies EkoBalans (a struvite based product with nitrogen and potassium added) and Outotec (a P-product with origin from incinerated sewage sludge) were used as case products. These products were also used in wp 3 where physical properties were evaluated and spreading tests were executed using existing machinery. The project provided a useful set of methods which soon will be complemented with methods to assess plant nutrient efficiency