Biomass digestate was treated with ag. solns. of H3PO4 and H2SO4 as well as ag. slurry of Ca(OH)(2). The superphosphate was also added. The resulting product was sepd. into a lig. fraction and a solid by pressure filtration. The lig. fraction showed yellow color, turbidity in range of 123-162 NTU, and COD 2000 mg/L The N content was approx. 900 mg/L The solid phase contained hydroxyapatite (8% of P and 0.6% of K).