| 摘要 |
<p>PURPOSE:To wash filter medium without using a submerged pump. CONSTITUTION:An air lift pump 22 for washing consisting of an almost Z-shaped back washing pipe 23 connecting a water collecting chamber 5 formed at the lower part of filter medium of a biological membrane filter tank 2 to a bottom part 8 side of a treated water tank 3 and an air supply pipe 27 connected to the prscribed position at the lower part of a vertical pipe 25 of the back washing pipe 24 and communicated to an air supply source is provided, and the treated water in the treated water tank 3 is sent to the water collecting chamber 5 together with air by supplying the air from the air supply pipe 27. Moreover, the air the treated water are sent to the filter medium to strip off sludge, etc., stuck to the filter medium and sent to the upper part of the filter meidum.</p> |
