| 摘要 |
<p>It is possible to chemically treat a biomass in the form of domestic animal manure, slurry, organically loaded effluent waste water and the like, which makes it possible to separate the fertilizing substances N, P and K and to obtain a water fraction which meets the requirements for discharge directly to a recipient. This is obtained by treating fresh biomass mechanically and/or chemically, e.g. by simple precipitation and enzymatic decomposition of the fibre content or by degasification of the manure. Phorphorus and nitrogen in the pre-treated biomass are precipitated by adding chemical reactive agents. The reactive agents are caused to react with the nitrogen compounds and the phosphorus compounds present to form new compounds which can be precipitated. Any urea content is precipitated together with nitrogen and phosphorus. Potassium is also precipitated together with nitrogen and phosphorus before separation of the biomass into the liquid fraction and the fertilizer fraction. The chemical reactive agents comprise metal ions and organic and inorganic acids.</p> |
