To provide a method and an apparatus for reducing an installation area, facilitating operation management, reducing a facility installation cost and an operation cost, and obtaining a high quality clean water.
Raw water is supplied into a treatment tank 1 built in a granulated activated carbon 2 adhering aerobic microbes to the surface thereof, an organic matter in a liquid inside the tank 1 of the raw water supplied into the treatment tank 1 is adsorbed on the surface of the activated carbon 2, and the organic matter is decomposed by the aerobic microbes. A decomposed organic matter and other suspended matter are filtered and separated by a filtration membrane unit 3 dipped into the liquid inside the tank. When the concentration of the suspended matter in the liquid inside the treatment tank 1 increases, the liquid inside the tank is withdrawn from the treatment tank 1. The withdrawing of the liquid inside the tank from the treatment tank 1 is carried out by lifting the liquid surface by increasing a supplied amount of the raw water into the treatment tank 1, and overflowing those from a water withdrawing port 25 formed at a position located higher than the liquid surface inside the tank at a peripheral wall of the treatment tank 1.
HIRATA NAOKO
MATSUMOTO TOMOKI
