| 摘要 |
<p>A treatment tank ( 1 ) for the secondary treatment of sewage, for providing the processes of aeration, nitrification and denitrification, in a single structure, for which a single, small horsepower, effluent pump ( 26 ) is the only moving part. In the treatment tank ( 1 ), the sewage is subjected to two separate biological treatments, in two separate chambers under different conditions. One biological treatment is carried out under anoxic conditions in a pipe coil ( 3 ). Anoxic conditions are ensured by keeping the pipe coil ( 3 ) full at all times; the pipe coil axis is vertical, and the pump forces the fluid flow upwardly through the coil. The second biological treatment is carried out under aerobic conditions in a trickle down filter ( 8 ). In a preferred embodiment, a welded pipe coil ( 3 ) used both to provide the anoxic conditions and to provide a tank containing the trickle down filter ( 8 ). The secondary treatment tank is generally used as part of a raw sewage treatment system, which will include a recycle loop which ensures that even when there is no raw sewage entering the system there is always a flow of liquid through the treatment tank.</p> |
