TANK AND METHOD FOR SEWAGE CLEANING

PROBLEM TO BE SOLVED: To provide a tank and a method for sewage cleaning made still more compact than before and capable of stably cleaning sewage. SOLUTION: The sewage cleaning tank is constituted of a first tank for sedimenting a sedimentary solid in inflow sewage under gravity and allowing a floatable solid to overflow to a next tank (second tank), a second tank storing the overflown floatable solid to separate the same into an upper layer part rich in the floatable solid and a lower layer part to transfer the liquid to a next tank (third tank) from the lower layer part thereof, the third tank subjecting the transferred liquid to biological treatment, a fourth tank for filtering the filtrate, which is obtained by filtering biological sludge (SS) increased in the third tank to transfer the filtrate to a next tank (fifth tank) and the fifth tank for disinfecting the transferred filtrate.