Method for recovering phosphate from a biomass material, said method comprising the steps of: (a) contacting in a contact tank said biomass material together with a liquid concentrate stream rich in volatile fatty acids (VFA's) and solubilised P with reduced content of solids resulting from step (g), for producing a mixed sludge, (b) separating in a thickener unit the mixed sludge of step (a) into: a concentrated thickened sludge product with reduced P and Mg levels, and a liquid concentrate stream rich in P and Mg, (c) subjecting said concentrated thickened sludge product to an anaerobic digestion stage in an Anaerobic Digester for producing a biogas stream and a digested sludge product, and retrieving said biogas, (d) separating in a first-dewatering stage said digested sludge product into a first digested sludge product containing solid particles, and a liquid concentrate rich in PO 4 -P and NH 4 -N (e) transferring said liquid concentrate rich in P and Mg from step (b) and said liquid concentrate rich in PO 4 -P and NH 4 -N from step (d) into a phosphate recovery process for producing a phosphate salt, (f) subjecting said first digested sludge product from step (d) to a thermal hydrolysis stage in a thermal hydrolysis unit for converting the solid particles of said first digested sludge product at least partially into soluble organic material, thereby forming a thermally hydrolized sludge product, (g) separating in a second dewatering stage said digested and thermally hydrolysed sludge product into a second digested and thermally hydrolysed sludge product, and a liquid concentrate stream rich in volatile fatty acids (VFA's), solubilised P and optionally colloidal organic material; separating in a separating unit at least a portion of said liquid concentrate into a cake product and a liquid concentrate stream with reduced content of solids; and recycling said cake product to the anaerobic digestion stage of step (c). (h) recycling said liquid concentrate stream rich in volatile fatty acids (VFA's) and solubilised P with reduced content of solids resulting from step (g) to step (a). (a) contacting in a contact tank said biomass material together with a liquid concentrate stream rich in volatile fatty acids (VFA's) and solubilised P with reduced content of solids resulting from step (g), for producing a mixed sludge, (b) separating in a thickener unit the mixed sludge of step (a) into: a concentrated thickened sludge product with reduced P and Mg levels, and a liquid concentrate stream rich in P and Mg, (c) subjecting said concentrated thickened sludge product to an anaerobic digestion stage in an Anaerobic Digester for producing a biogas stream and a digested sludge product, and retrieving said biogas, (d) separating in a first-dewatering stage said digested sludge product into a first digested sludge product containing solid particles, and a liquid concentrate rich in PO 4 -P and NH 4 -N (e) transferring said liquid concentrate rich in P and Mg from step (b) and said liquid concentrate rich in PO 4 -P and NH 4 -N from step (d) into a phosphate recovery process for producing a phosphate salt, (f) subjecting said first digested sludge product from step (d) to a thermal hydrolysis stage in a thermal hydrolysis unit for converting the solid particles of said first digested sludge product at least partially into soluble organic material, thereby forming a thermally hydrolized sludge product, (g) separating in a second dewatering stage said digested and thermally hydrolysed sludge product into a second digested and thermally hydrolysed sludge product, and a liquid concentrate stream rich in volatile fatty acids (VFA's), solubilised P and optionally colloidal organic material; separating in a separating unit at least a portion of said liquid concentrate into a cake product and a liquid concentrate stream with reduced content of solids; and recycling said cake product to the anaerobic digestion stage of step (c). (h) recycling said liquid concentrate stream rich in volatile fatty acids (VFA's) and solubilised P with reduced content of solids resulting from step (g) to step (a).