Abstract A sewage treatment apparatus or plant wherein treatment of the sewage is achieved by aeration. The apparatus consists of a tank having an inlet for raw sewage and an outlet for decomposed sewage, and an inclined baffle structure between the inlet and outlet to divide the tank into an aeration chamber and a settling chamber. The inclined baffle structure permitting sewage flow beneath and above the baffle structure, and a compressor for delivering air under pressure to an air diffuser positioned adjacent the lowermost portion of the inclined baffle structure whereby air in the form of bubbles issuing from the diffuser results in countercurrent flow in the aeration and settling chambers causing intimate mixing and aeration of all of the sewage in the tank. The apparatus also provides for means for returning scum from the surface of the settling chamber to the aeration chamber.
Sewage treatment apparatus according to claim 1, wherein said guide plate consists of a diffuser plate extending completely across the tank, and said air diffuser means is mounted on said diffuser plate, and further comprising an air channel secured to the surface of the diffuser plate remote from the inclined baffle structure, said conduit being connected to said air channel, and one or more longitudinal rows of apertures in the diffuser plate whereby air under pressure moves from the air channel through the apertures and into the space between the inclined baffle structure and the diffuser plate.
Claim 2
Dependent Claim
25 words
Apparatus according to claim 1, further comprising means for returning scum from the surface of the sewage in the settling chamber to the aeration chamber.
Claim 3
Dependent Claim
79 words
Apparatus according to claim 3 wherein the scum returning means consists of a scum tray positioned below the surface of the sewage in the settling chamber and a U-shaped conduit extending from the scum tray through the inclined baffle structure and terminating in a scum outlet formed above the sewage in the aerating chamber, and a conduit conveying air under pressure to the U-shaped conduit to move by partial vacuum scum from the scum tray to the scum outlet.
Claim 4
Dependent Claim
31 words
Apparatus according to claim 1, further comprising a bottom baffle projecting upwardly from the bottom of the tank and extending completely across the tank and inclined toward the inclined baffle structure.