| 摘要 |
<p>The present invention relates to a method of recovering phosphate from biomass such as animal manure, waste slurries, organically loaded waste water etc. The method recovers phosphate from a feed mixture comprising a liquid phase and a solid material in which mixture metals are present. The method comprises the following steps: a. assuring a pH < 3.5 and adding an oxidation agent thereby dissolving at least a part of the solid material and increasing the metal and phosphate content in the liquid phase; b. separating remaining solid from the liquid phase; c. after having separated solids from the liquid phase, components having affinity for forming insoluble compounds with PO4 at pH > 3 are removed from the liquid phase and then pH is increase to > 3 in the liquid phase and an agent for precipitating metal ions is added; d. separating the precipitated metal compounds from the liquid phase; e. adding alkaline (MgO, NaOH etc.) and increasing pH to > 8 in the liquid phase; f. separating the precipitated phosphate and nitrogen from the liquid phase.</p> |
