Recovery of phosphorous from waste water (circularity)

Last update: 2 June 2023

• Action: Use of phosphorus recovered with origin in waste-water.
• Animal category: All species.
• Technique: The use of recovered phosphorous from sewage sludge ash in animal feed (not allowed yet) as opposed to sourcing rock phosphates from mines with finite resources.
• Mode of action: Modern techniques and innovative chemical recycling enable safe recovery of phosphates from sewage sludge incineration ash up to 90%.
• Mode of implementation: Replacement of rock phosphate by recovered phosphorous in feed formulation.
• Requirements/limitations: The use of recycled phosphorous with origin in waste-water in animal feed is not allowed today.
• Economic consequences: The availability of phosphorous for feeding purposes would increase in the short term once approved in the EU, while in the long term it may be a necessity bearing in mind the finite availability of rock phosphate; competition with the use as fertilisers may impact on the competitiveness of recycled phosphorous in animal feed.
• Other considerations: The digestibility of recovered phosphorous is expected to be higher than rock phosphates and allows the reduction of phosphorous in diets and emissions of surplus in the environment; reduced use of rock phosphate would reduce the presence of uranium and cadmium contaminants, while it would stimulate the local bio-economy.
• References:
  • Luyckx et al. (2021). Recovery of phosphorus from sewage sludge ash: Influence of incineration temperature on ash mineralogy and related phosphorus and heavy metal extraction. Journal of Environmental Chemical Engineering 9(6):106471. https://doi.org/10.1016/j.jece.2021.106471
  • Shaikh (2018). Phosphorus recovery from sewage sludge and waste water treatment. International Conference On Sustainable Solutions in Industrial Pollution, Water and Wastewater Treatment. https://www.researchgate.net/publication/329144221