PURPOSE: To carry out the treatment of a sewage efficiently in a low cost by a method wherein 90% or more of a substance to be treated in a sewage is subjected to the initial adsorption treatment according to oxygen in air and 10% or less of the rest is subjected to the high or the pure oxygen aeration treatment.
CONSTITUTION: A sewage treatment apparatus is constituted by mounting a double baffle 7, a reverse tank 4, an outer cylinder and an inner aeration cylinder 2 in an outer tank 8 having a rectangular cross area succeedingly from an outer side. In an upper portion of a filter sludge bed 20 encircled by an inner wall of the outer tank 8 and an outside plate of the double baffle 7, a supernatant portion 19 is formed and, to an outer flange of the supernatant portion 19, a treated water flooding weir 17 and a discharge trough 18 are arranged. In the filter sludge bed 20, one end of a recirculation pipe 14 for recirculating and flowing a filter sludge is protruded and, to the end portion thereof, a stream guide plate 21 for preventing the filter sludge from being shortly connected to and flowed into the recirculation pipe 14 is provided.
TOYO GIKEN KK
KOGYO KAIHATSU KENKYUSHO KK