Abstract: A method of treating an animal waste slurry so as to efficiently extract nutrients, and which can be performed in a zero-discharge system, comprises flocculating the slurry, processing, e.g. filtering, the flocculated slurry to separate liquid from solid material, drying the solid material, processing the liquid to extract ammonium, phosphorous and potassium from the slurry, all within 24 hours, and preferably on average within 12 hours, of production of the waste material by animals. Since the urates of potassium and ammonium in the slurry take a few hours to break down, they remain in crystalline form and therefore a larger portion of the total amount of potassium and ammonium in the slurry can be extracted.

Abstract: A method of treating an animal waste slurry so as to efficiently extract nutrients, and which can be performed in a zero-discharge system, comprises flocculating the slurry, processing, e.g. filtering, the flocculated slurry to separate liquid from solid material, drying the solid material, processing the liquid to extract ammonium, phosphorous and potassium from the slurry, all within 24 hours, and preferably on average within 12 hours, of production of the waste material by animals. Since the urates of potassium and ammonium in the slurry take a few hours to break down, they remain in crystalline form and therefore a larger portion of the total amount of potassium and ammonium in the slurry can be extracted.