Abstract: A method and plant for the treatment of an organic waste material in liquid form, e.g. liquid manure from livestock, the method comprising filtering fibres and particles from the liquid, subjecting the liquid to anaerobic fermentation in a biogas reactor, separating a substantially sterile and particle-free permeate stream from the biogas reactor, e.g. using ultrafiltration, subjecting the permeate stream to treatment with an ammonia stripper at an elevated temperature and preferably at reduced pressure to remove substantially all ammonia and carbon dioxide and to result in an ammonia fraction and a nutrient salt fraction, and separating the nutrient salt fraction into a fertiliser concentrate fraction and a water fraction, e.g. using reverse osmosis. The end products of the method are clean water, ammonia concentrate, fertiliser concentrate containing salts of P and K, compost and high-quality biogas with a high methane content.

Abstract: Biological sewage treatment plant comprising at least one treatment or aeration tank (1, 2, 3,) for the biological process, having an inlet (6, 7) for sewage, an outlet (14, 8) for treated water and a conduit (1, 2, 3) for air supply down in each treatment tank. There is also provided a settling tank (4) with a conduit (10) for feeding back sludge from the bottom thereof to a preceeding treatment tank (1), said air supply conduit in each treatment tank (1, 2, 3) being provided with its outlet (1A, 2A, 3A) adjacent to a vertical wall in the treatment tank. A baffle plate (11A, 12A, 13A) extends from a level above the operational water level in the treatment tank at an inclination downwards-inwards towards a vertical wall part in the tank opposite said vertical tank wall, for establishing a clarifier chamber (11, 12, 13) which is separated from the main part of the tank, but communicates with the latter through a lower opening in the clarifier chamber.