TECHNOLOGY FOCUS - ENVIRONMENT - Preferred Method: The separation is performed by a filter. The elimination of gas is performed by degradation by micro-organisms and/or solubilization in clarified aqueous phase. The flocculating agent is added to the separation system or electrochemical system with the liquid manure to precipitate phosphorus and nitrogen compounds. The method further includes recycling fibers obtained from dehydrated solid phase of manure to form a derived filter. The contaminants are separated from the clarified aqueous phase to provide purified and disinfected water. The purified and disinfected water is returned to nature or recycling at least a part in an animal production plan or liquid manure treatment system.    TECHNOLOGY FOCUS - MECHANICAL ENGINEERING - Preferred Components: The separation system performs sifting, riddling, filtration, settling, sedimentation, and/or pressing. The filter is membrane filter, porous hard wall, cloth drum type, or tangential filter. The draining system evacuates the liquid manure from animal production farm and displaces the liquid manure to the separation system. The electrochemical system comprises a water streaming filter. The system further includes a derived filter system using fibers obtained from dehydrated solid phase of manure. The electrochemical system comprises conduit(s) for collecting the clarified aqueous phase containing contaminants, electrochemical cell and a voltage source. The electrochemical cell comprises a container (12) for receiving clarified aqueous phase. The container has at least two parallel electrolytic plates. The voltage source is connected to positive and negative plates (20) for applying a difference potential. The difference potential causes the contaminants in reaction with the electrolytic plates to flocculate and to float.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The flocculating agent comprises metal particles, cationic compound, anionic compound, iron salt, aluminum salt, magnesium salt, ferrous chloride, ferrous sulfate, ferric chloride, ferric sulfate, chlorinated ferric sulfate, basic aluminum sulfate, chlorinated basic aluminum sulfate, magnesium chloride, or magnesium sulfate.