| 摘要 |
<p>PROBLEM TO BE SOLVED: To make it possible to efficiently purify water to be treated with a lower displacement by providing a device for treating the water to be treated by passing the water in downward current to packed material layers deposited with microorganism membranes with an intermediate washing pipe for passing air and/or water in upward current at the intermediate layer section up to a specific layer height thereof. SOLUTION: The biological treating column 1 is internally provided with the packed material layers 2 on a supporting bed 3 and is provided with the intermediate washing pipe 8 in the intermediate layer section below the front layer surface thereof. At this time, the position where the intermediate washing pipe 8 is installed is set in a position lower by about 100 to 500m from the front layer surface up to 1/3 the layer height. The boundary surface between the packing material layers 2 and the supporting bed 3 is provided with an entire layer air washing pipe 11 and the bottom of the supporting bed 3 is provided with a water collecting pipe 12, to which a treated water pipe 13, an entire layer back washing pipe 14 and a downward current washing drain pipe 15 are connected. The packing material layers 2 are washed by passing the air and water in the upward current from the intermediate washing pipe 8 when the press drop at the time of passing the water attains a prescribed value.</p> |
