Verfahren zur Reinigung phosphathaltiger Abwaesser mittels biologischer Phosphorelimination sowie Anlage zur Durchfuehrung dieses Verfahrens

摘要

For improvement of the phosphate redissolution taking place under anaerobic conditions, the treatment is conducted under anaerobic conditions, preferably in a settling tank, into which unsettled raw sewage and a return sludge from the secondary settling tank are introduced. The sludge retention time of the return sludge is generally over 5 hours, preferably 10-24 hours. In any case, the sludge detection time exceeds the hydraulic detection time. The new process can be performed by using most existing plants with relative small investment expenditures and provides a phosphorus elimination on the order of magnitude of 90%.