The determination of fertilizer quality of the formed struvite from effluent of a sewage sludge anaerobic digester

J Hazard Mater. 2010 Sep 15;181(1-3):248-54. doi: 10.1016/j.jhazmat.2010.05.004. Epub 2010 May 11.


The formation of struvite (MgNH(4)PO(4).6H(2)O) in wastewater treatment plants can lead to scaling and thus operational problems reducing the treatment efficiency. However, struvite has significant commercial value as an agricultural fertilizer. Therefore, controlled struvite formation in wastewater treatment plants not only presents an opportunity to recover nutrients but also corresponds to the valorization of wastes. NH(4)-N and PO(4)-P removal and recovery from the effluent of a full-scale sewage sludge anaerobic digester via controlled struvite precipitation were investigated in this study. The effect of the residual heavy metal and micropollutant content of the formed struvite on fertilizer quality was also evaluated. Removal efficiencies of NH(4)-N, PO(4)-P and COD were 89.35%, 95% and 39.78% when Mg:N:P molar ratio was 1.5:1:1 and pH was 9.0. Mercury, nickel, zinc and chrome concentrations derived from struvite precipitation were below the regulatory limit for fertilizer usage in Turkey. The precipitate did not contain polychlorinated biphenyls (PCB). X-ray diffraction (XRD) analysis conducted on the precipitate indicated a struvite formation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anaerobiosis
  • Biodegradation, Environmental
  • Chemical Precipitation
  • Fertilizers / analysis*
  • Fertilizers / standards
  • Magnesium Compounds / analysis
  • Magnesium Compounds / chemistry*
  • Phosphates / analysis
  • Phosphates / chemistry*
  • Phosphates / isolation & purification
  • Quaternary Ammonium Compounds / isolation & purification
  • Sewage / chemistry*
  • Sewage / microbiology
  • Struvite
  • Turkey
  • Water Pollutants
  • Water Purification / methods


  • Fertilizers
  • Magnesium Compounds
  • Phosphates
  • Quaternary Ammonium Compounds
  • Sewage
  • Water Pollutants
  • Struvite