Cow urine as a potential source for struvite production

Background Rock phosphate deposits are non-renewableand are facing a decline. Due to this, phosphate fertilizersare going to be limited in future. Struvite is a crystallinemineral substance containing equimolar amount (1:1:1) ofmagnesium ammonium and phosphate ions (MgNH4PO4-6H2O), a good source of phosphorus and a slow releasefertilizer. In the present study it was crystallized from cowurine using brine as cheap source of magnesium. Cow urineand brine was mixed at different proportion to find out theoptimum concentration for struvite crystallization. Crystallizedstruvite was characterized by X-ray diffraction,thermogravimetric and differential thermal analysis, Fouriertransform infrared spectroscopy and scanning electronmicroscopy and energy dispersive spectroscopy.Results The ratio of 1:0.5 cow urine and brine mixinggave the best quality struvite at pH 9. The analysis ofstruvite for phosphate, magnesium and ammonium ionsshowed 5.85, 3.16, and 0.56 % respectively. The fertilizerpotential of struvite was evaluated on the growth of Vignaradiata. The best growth was observed in the pots wherestruvite was added at a concentration of 2 g/kg of soil.Conclusion Struvite is a good source of phosphate and itcan be recovered from livestock waste such as cow urine.Struvite can be made from a renewable source for a sustainableagricultural development. Theoretically at theyield of 40 g/L a total of 12,176 tons struvite could bemade per day all over India for fertilizer use.