Process and system for recovering phosphorus from wastewater

Abstract

Methods and systems for recovery of phosphorus from wastewater and producing inorganic phosphorus complexes.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
         1 . A method for producing inorganic phosphorus from wastewater, comprising:
 (a) thickening a phosphorus- and magnesium-containing mixture derived from microorganisms induced to release phosphorus and magnesium to provide a phosphorus- and magnesium-rich liquid and a phosphorus- and magnesium-reduced mixture;   (b) conducting the phosphorus- and magnesium-rich liquid to a first inorganic phosphorus reactor;   (c) anaerobically treating the phosphorus- and magnesium-reduced mixture to provide an ammonia-rich, phosphorus- and magnesium-reduced mixture;   (d) separating a first ammonia-rich, phosphorus- and magnesium-reduced liquid from the ammonia-rich, phosphorus- and magnesium-reduced mixture;   (e) conducting the first ammonia-rich, phosphorus- and magnesium-reduced liquid to a second inorganic phosphorus reactor to provide inorganic phosphorus and a second ammonia-rich, phosphorus- and magnesium-reduced liquid; and   (f) adding ammonia to the phosphorus- and magnesium-rich liquid in the first inorganic phosphorus reactor to provide inorganic phosphorus.   
     
     
         2 . A system for producing inorganic phosphorus from wastewater, comprising:
 (a) a first solids separator for thickening a phosphorus- and magnesium-containing mixture;   (b) a first inorganic reactor, the reactor having a conduit for receiving ammonia;   (c) a first conduit intermediate the first solids separator and the first inorganic phosphorus reactor;   (d) a digester;   (e) a second conduit intermediate the first solids separator and the digester;   (f) a second solids separator;   (g) a third conduit intermediate the digester and the second solids separator;   (h) a second inorganic reactor; and   (i) a fourth conduit intermediate the second solids separator and the second inorganic phosphorus reactor.