| 摘要 |
<p>1. Process for the purification of supernatant liquors from night-soil from domestic sewage treatment plants, comprising a presedimentation, a biological purification stage with simultaneous phosphate precipitation, a nitrification stage and a final sedimentation, characterized by the combination of the following features : that the presedimentation takes place in a sludge tank constructed as collecting and settling tank, which is followed by a separation tank for the further separation of heavy sediments, that a succeeding biological-chemical purification stage by the percolating filter method by means of cylinder aerators or percolating filters is provided, an intensified flocculation of suspended materials that cannot be settled or of colloidally dissolved substances being carried out by a simultaneous phosphate precipitation by addition of a chemical precipitation agent after the percolating filters and a precipitation of the phosphates contained in the effluent being carried out, and a separation of the precipitated substances being carried out in a succeeding first final sedimentation tank, that the breakdown of ammonium-nitrogen and nitrite-nitrogen is carried out in a nitrification stage which takes place in a circular tank with pressurized air aeration system and a filling of foam plastics cubes as support material for bacteria, that nitrate-containing effluent from the outlet from the nitrification stage is fed to the separation tank upstream of the biological purification stage for the carrying out of a denitrification, and that the effluent from the nitrification stage is fed via a second final sedimentation tank and a mechanical final clarification filter to the main channel.</p> |
