Struvite crystallization versus amorphous magnesium and calcium phosphate precipitation during the treatment of a saline industrial wastewater.

Struvite crystallization (MgNH(4)PO(4)·6H(2)O, MAP) could be an alternative for the sustainable and economical recovery of phosphorus from concentrated wastewater streams. Struvite precipitation is recommended for those wastewaters which have high orthophosphate concentration. However the presence of a cheap magnesium source is required in order to make the process feasible. For those wastewater treatment plants (WWTP) located near the seashore magnesium could be economically obtained using seawater. However seawater contains calcium ions that could interfere in the process, by promoting the precipitation of amorphous magnesium and calcium phosphates. Precipitates composition was affected by the NH(4)(+)/PO(4)(3-) molar ratio used. Struvite or magnesium and calcium phosphates were obtained when NH(4)(+)/PO(4)(3-) was fixed at 4.7 or 1.0, respectively. This study demonstrates that by manipulating the NH(4)(+)/PO(4)(3-) it is possible to obtain pure struvite crystals, instead of precipitates of amorphous magnesium and calcium phosphates. This was easily performed by using either raw or secondary treated wastewater with different ammonium concentrations.

[1]  C. Rey,et al.  Amorphous calcium phosphates: synthesis, properties and uses in biomaterials. , 2010, Acta biomaterialia.

[2]  S. Uludag-Demirer,et al.  Removal of ammonium and phosphate from the supernatant of anaerobically digested waste activated sludge by chemical precipitation. , 2009, Bioresource technology.

[3]  N. Ellis,et al.  Effects of various process parameters on struvite precipitation kinetics and subsequent determination of rate constants. , 2008, Water science and technology : a journal of the International Association on Water Pollution Research.

[4]  M. F. Colmenarejo,et al.  Removal of phosphorus through struvite precipitation using a by-product of magnesium oxide production (BMP): Effect of the mode of BMP preparation , 2008 .

[5]  M C M van Loosdrecht,et al.  Phosphate and potassium recovery from source separated urine through struvite precipitation. , 2007, Water research.

[6]  Eugenia Valsami-Jones,et al.  Impact of calcium on struvite crystal size, shape and purity , 2005 .

[7]  Y. Bashan,et al.  Recent advances in removing phosphorus from wastewater and its future use as fertilizer (1997-2003). , 2004, Water research.

[8]  J. Lester,et al.  Removal of Struvite to Prevent Problems Associated with its Accumulation in Wastewater Treatment Works , 2004, Water environment research : a research publication of the Water Environment Federation.

[9]  A. K. Sarkar,et al.  Characterization of soil-fertilizer P reaction products and their evaluation as sources of P for gram (Cicer arietinum L.) , 2004, Nutrient Cycling in Agroecosystems.

[10]  C. W. Lee,et al.  Removal of nitrogen and phosphate from wastewater by addition of bittern. , 2003, Chemosphere.

[11]  S. Parsons,et al.  Struvite formation, control and recovery. , 2002, Water research.

[12]  P Pearce,et al.  Potential phosphorus recovery by struvite formation. , 2002, Water research.

[13]  J. Lieto,et al.  PHOSPHATE RECOVERY BY STUVITE PRECIPITATION IN A STIRRED REACTOR , 2002 .

[14]  E. V. Münch,et al.  Controlled struvite crystallisation for removing phosphorus from anaerobic digester sidestreams. , 2001, Water research.

[15]  Y. Matsumiya,et al.  Phosphorus Removal from Sidestreams by Crystallisation of Magnesium‐Ammonium‐Phosphate Using Seawater , 2000 .

[16]  R. D. Schuiling,et al.  Recovery of struvite from calf manure , 1999 .

[17]  E. Choi,et al.  Nutrient control with other sludges in anaerobic digestion of BPR sludge , 1998 .

[18]  D. Orhon,et al.  Ammonia removal by magnesium ammonium phosphate precipitation in industrial wastewaters , 1997 .

[19]  Kwang Victor Lo,et al.  Removal of nitrogen from swine manure wastewaters by ammonia stripping , 1995 .