PURPOSE: To efficiently remove an organism adhered to and penetrated into a sponge carrier, by intermittently taking out a part of the sponge carrier having the organism adhered thereto from a treating tank to bring the same into contact with an acidic liquid.
CONSTITUTION: A porous sponge like substance 2 is introduced into the treating tank 1 of a fluidized bed type biological treatment apparatus as a microorganism carrier and fluidized by diffusing air from an air diffusing apparatus 3 provided to the bottom of the tank 1 to treat sewage supplied into and stayed in the treating tank 1 with the organism adhered to the sponge like substance 2. A discharge means 4 comprising a drum for discharging the sponge like substance 2 while rotated by a horizontal drive shaft is provided to the treating tank 1 while the discharged sponge substance 2 is taken out from a flooding port 1' and drained by a screen apparatus 5 to be fallen in an immersion tank 7 into which an acidic liquid is introduced. The sponge like substance 2 is stirred by rotating a rake 7' and successively discharged out of the tank 7 to be squeezed through a squeezing apparatus 8. The squeezed sponge like substance 2, from which the microorganism is removed, is neutralized in a neutralization tank 10 before returned to the treating tank 1 through a conduit 12.
SUZUKI KAZUO
MIYAHARA MAKIKO
MIYAJI ARIMASA
