crystallisation of struvite from urine

摘要

A method for the recovery of nutrients from human urine substantially free of excrements and other debris is described. Said method comprises the following steps: A) the urine is concentrated; B) struvite crystallisation is initiated in the concentrated urine by adding MgO; and C) the struvite crystals are separated from the solution. The method may also comprise a further step, step D), in which nitrogen is recovered from the solution obtained in step C) by ammonia adsorption, preferably by the use of wollastonite or clinoptilolite. The struvite and the ammonium containing adsorbent are suitable for use as fertilizers.