Process and apparatus for the purification of phosphate- and nitrogen-containing waste water

摘要

To purify phosphate- and nitrogen-containing waste water (effluent), a biomass having high phosphorus content is produced from the waste water with biological elimination of phosphorus and nitrogen. The biomass is separated off and subjected to an anaerobic digestion process, a phosphate- and ammonium ion-containing filtrate being obtained. The phosphate is precipitated out from the filtrate and the precipitated solids are separated off from the aqueous phase. In order to obtain an effective elimination of phosphorus and nitrogen, in a collective precipitation operation, phosphate ions and ammonium ions are simultaneously precipitated out of the filtrate as magnesium ammonium phosphate (MgNH4PO4.6H2O).