Recovery of phosphorus in the struvite form of the slime and food digestion supernatant on the pilot scale

Recovery of PO4 3- and NH4 + from the anaerobic digestion supernatant of sewage sludge and feed in the form of struvite using different concentrations of nutrients in two anaerobic digestion units submitted separately to the exclusive processing with sludge, as well as to the mixture between sludge sewage and crushed food. This process occurs in two stages: the first stage with three sources of magnesium MgSO4, MgCL2, MgOH2, and in the second stage added food crushed next to the sewage sludge in the anaerobic digester. For the increase in PO4 3- and NH4 + , concentration in the supernatant that upon reacting with magnesium precipitated during the mechanical mixing at different concentrations of NH4 + and PO4 3- , which condition the amounts of magnesium added in the treatment of struvite. Further removal of PO4 3- , 83.8%, in MgSO4 precipitates in the supernatant, at a concentration of 20% PO4 3-. Struvite form to recover the phosphorus from the supernatant of the anaerobic digestion with the organic materials used.