JUKISEISANSEIHAISUINOSEIBUTSUSHORIHOHOOYOBISOCHI

摘要

PURPOSE:To save a neutralization treatment stage by returning the separated activated sludge in a settling chamber to the raw water of the waste water to be supplied to a three-phase fluidizing tank in such a manner that the pH value of the three-phase fluidizing tank is maintained in a specific range adequate for an aerobic biological treatment. CONSTITUTION:The pH of the water to be treated in the three-phase fluidizing tank 4 is kept detected at all times by a pH sensor 19 and the sludge material in the settling tank 10 is adjusted and supplied by an electromagnetic stop valve 17 to the three-phase fluidizing tank 4 so that the pH of the water to be treated in the tank 4 is maintained in a 6.5 to 7.5 range. The sludge is collected to the center of the tank 10 and settles in the bottom of the tank in the settling tank 10. The neutralization of the liquid mixture only by the sludge material formed in the three-phase fluidizing tank 4 is possible according to this device. The need for the neutralization treatment stage is entirely eliminated in this way.