Phosphorus removal from a real anaerobic supernatant by struvite crystallization

In this paper the phosphorus removal from a real anaerobic supernatant through the crystallization of struvite and or hydroxyapatite was investigated. A comparison between experimental results on phosphorus crystallization carried out in a fluidized-bed reactor (FBR) on a bench-scale and on a half-scale plant is presented, together with a double saturational model able to describe all experimental results, independent of the different geometry of the reactors, the distinct contact times and the unlike products obtained. Experimental results show that removal efficiencies are very satisfactory, and the maximum phosphorus removal is of 80%.