How to Enhance Phosphorus Recovery from Urine as Struvite During Its Storage?

Phosphorus is a non-renewable and exhausted resource and urine is an ideal candidate for its sustainable recovery. This work investigates the recovery of phosphorus as struvite during the storage of urine using different volumetric ratios of fresh/hydrolyzed urine, and two magnesium sources, seawater and brine, to promote struvite crystallization. Results indicate that the addition of hydrolyzed urine to fresh urine would be a suitable strategy to improve urea hydrolysis, and consequently to reduce the storage time for phosphorus precipitation from urine when seawater was added, obtaining high efficiencies for its recovery. Up to 87% of phosphorus was recovered as struvite from urine when fresh urine is mixed with hydrolyzed urine and seawater was added.