The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 17, 2012
Filed:
Jul. 14, 2008
Tianxi Zhang, Pullman, WA (US);
Keith E. Bowers, Seattle, WA (US);
Joseph H. Harrison, Puyallup, WA (US);
Shulin Chen, Pullman, WA (US);
Tianxi Zhang, Pullman, WA (US);
Keith E. Bowers, Seattle, WA (US);
Joseph H. Harrison, Puyallup, WA (US);
Shulin Chen, Pullman, WA (US);
Washington State University Research Foundation, Pullman, WA (US);
Multiform Harvest, Inc., Seattle, WA (US);
Abstract
Particular aspects provide a method for recovering phosphate, comprising: obtaining an effluent or wastewater, etc. having calcium-sequestered phosphate; adding to the effluent or wastewater a calcium chelating or sequestration agent suitable to chelate or sequester Caions from the calcium-sequestered phosphate to facilitate release of phosphate from the calcium-sequestered phosphate; transferring, facilitated by said Caion capture and in the presence of sufficient concentrations of NHand Mgions, of the phosphate into struvite (magnesium ammonium phosphate hexahydrate or MgNHPO.6HO), or hydrated magnesium ammonium complex of phosphate; and recovering the struvite, or the formed hydrated magnesium ammonium complex. Preferably, the method further comprises acidification of the effluent or wastewater to facilitate release of Caions from the calcium-sequestered phosphate and chelation of sequestration of the Caions by the calcium chelating or sequestration agent. Additional aspects provide a phosphate-containing fertilizer comprising struvite, and methods for making same.