| 摘要 |
PURPOSE:To perfectly treat excessive sludge, by a relatively simple and small sewage treating apparatus wherein excessive sludge adhered to the pebble layer on a perforated plate is released by forcibly feeding air from an air diffusion pipe provided to the bottom part of a sewage treating tank and decomposed in an aqueous system filter material layer provided the upper part of the tank wall. CONSTITUTION:Sewage is supplied into a sewage treating tank 1 so as to bring the variable surface of sewage to the highest level with respect to excessive sludge adhered to pebbles 3 and, at the same time, air is sent to an air diffusion pipe 6 in an amount of several times as compared with a usual amount to generate a water stream in the tank 1 and the excessive sludge adhered to the pebbles 3 is forcibly released. As a result, a liquid mixture of released sludge and sewage filling the tank 1 is sent into an aqueous system filter material 9 under pressure by a pump P2 through a conduit T and a ceramic pipe 9 provided to the upper part of the tank 1. In this case, moisture is recirculated into the tank 1 from the recessed part of a mountain shaped net 4 and sludge holding a proper amount of moisture remaining in the filter material 9 is subjected to biological decomposition (soil animals, soil microorganisms and plant roots). |
