SYSTEM FOR EXTRACTING STRUVITE Russian patent published in 2012 - IPC C02F3/00 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of treating waste water with sludge. The system for extracting struvite comprises: a first clarifier for obtaining first sludge and a stream of organic wastes from waste water; a bioreactor for fermentation of organic wastes in the stream of waste water for obtaining fermented sludge and a first thickener for thickening the fermented sludge; wherein the bioreactor and the first thickener together form easily biodegradable carbon-containing compounds from organic wastes in the stream of waste water; an aerotank for reaction of carbon-containing compounds from the first thickener with solid materials suspended in the mixed liquid, wherein the aerotank is connected with a second clarifier, at the output of which activated sludge is obtained; a separator connected with the first thickener and the second clarifier for obtaining a stream rich in phosphorus and magnesium, and a separate stream depleted of phosphorus and magnesium; an enzymolysis reactor connected to the separator for decomposition of the stream depleted of phosphorus and magnesium, together with the fermented sludge; dehydration apparatus connected to the enzymolysis reactor for obtaining sludge depleted of phosphorus and magnesium but rich in ammonia; and a struvite reactor for reaction of sludge rich in ammonia and the stream rich in phosphorus and magnesium to form struvite rich in ammonia, phosphorus and magnesium.

EFFECT: invention enables to reduce undesirable formation of struvite in an anaerobic bioreactor.