Precipitation of urinary phosphate

Basakcilardan-Kabakci S., Ipekoglu A. N., Talinli I.

ENVIRONMENTAL ENGINEERING SCIENCE, vol.24, no.10, pp.1399-1408, 2007 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 24 Issue: 10
  • Publication Date: 2007
  • Doi Number: 10.1089/ees.2006.0136
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.1399-1408
  • Istanbul Technical University Affiliated: Yes


Struvite precipitation is an effective process for removing and recovering phosphate from separately collected fresh urine. Present study experimentally investigated the effect of reaction time, reaction pH, and initial molar Mg:P ratio on struvite precipitation. Results showed that reaction time had a negligible effect on phosphate removal, and pH influenced both phosphate removal efficiency and the composition of the precipitate. Precipitates obtained at pH 9 were crystalline struvite which was confirmed by the FTIR and X-ray diffraction analysis. Studying at a molar ratio below 1Mg:1P enhanced the formation of amorphous calcium phosphate and decreased the purity of the precipitate with respect to struvite. Struvite precipitation from fresh urine (1.57 Mg:1P) achieved at pH 9 in 1-h reaction time resulted in 96% of PO43- -P and 52.5% of NH3-N removal. High phosphate recovery obtained in this experimental study indicated that combining urine separation with struvite precipitation is a promising idea toward sustainable environment.