Patent ID: 8158089

Claim:
A method for recovery of phosphate, in the form of struvite, from a fluid or hydrated magnesium ammonium complex of phosphate, composition, effluent, wastewater or solution having non-struvite calcium-sequestered phosphate, comprising: obtaining a fluid composition, effluent, wastewater or solution comprising non-struvite calcium-sequestered phosphate; adding to the fluid composition, effluent, wastewater or solution a calcium chelating or sequestration agent suitable to chelate or sequester Ca ++ ions from the non-struvite calcium-sequestered phosphate to facilitate release of phosphate from the non-struvite calcium-sequestered phosphate; and accumulating, facilitated by said Ca ++ ion capture, the released phosphate into struvite (magnesium ammonium phosphate hexahydrate or MgNH 4 PO 4 .6H 2 O), or hydrated magnesium ammonium complex of phosphate, wherein phosphate is redistributed from the non-struvite calcium sequestered phosphate into struvite, and wherein a method for recovery of phosphate, in the form of struvite, or hydrated magnesium ammonium complex of phosphate, from a fluid composition, effluent, wastewater or solution having non-struvite calcium-sequestered phosphate is afforded.