| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a means for simply lowering the water level of a carrier filter tank at the time of washing of a filter carrier and a carrier separator hard to block up, capable of obtaining stable separation action and good in workability at the time of maintenance, in a sewage treatment apparatus using a carrier on which microorganisms are fixed. SOLUTION: At the time of washing of a filter carrier, the water level in an upstream tank positioned on the upstream side of the carrier filter tank is lowered by the forcible transfer of the filter carrier and the treated water in the carrier filter tank is transferred to the upstream tank to lower the water level in the carrier filter tank and, thereafter, the filter carrier in the carrier filter tank is washed. The surface of the filter screen of the carrier separator is arranged at the central part in the vicinity of the water surface of the tank in parallel to the water flow at the water surface part of the revolving flow in the carrier filter tank at an angle of 30<-<90 deg. with respect to the horizontal surface. Since the surface of the screen is arranged at the central part in the vicinity of the water surface, visual confirmation is easily performed and cleaning work by a brush, or the like, is easy.</p> |
