Abstract: A two stage clarifier apparatus for producing a clarified effluent from mixed liquor in a sewage treatment system wherein mixed liquor is partially clarified in a first quiescent zone in the first stage of the apparatus to produce a partially clarified effluent, the partially clarified effluent is transferred to an aeration zone in the second stage of the apparatus, a portion of the partially clarified effluent is transferred from the aeration zone to a second quiescent zone in the second stage of the apparatus, and fully clarified effluent is withdrawn from the second quiescent zone.

Abstract: An apparatus for treating sewage to obtain substantially complete organic matter substrate and biological sludge oxidation prior to effluent discharge in a treatment system comprising a series of treatment chambers in a single unit; each treatment chamber having a generally circular peripheral crosssectional configuration, conduit means in each treatment chamber for directing the flow of mixed liquor in each chamber, gas supply means for supplying an oxygen containing gas to each treatment chamber so as to cause a continuous flow pattern of mixed liquor in the treatment chamber; inlet means for supplying raw sewage to the first treatment chamber of the series; outlet means for withdrawing clarified effluent from the last treatment chamber of the series; and fluid communication means for providing fluid communication between an intermediate top portion of each successive treatment chamber of the series.

Abstract: An apparatus for treating sewage to obtain substantially complete organic matter substrate and biological sludge oxidation prior to effluent discharge in a treatment system comprising a series of treatment units; each unit having a generally circular cross-sectional configuration defining a treatment chamber, baffle means in the treatment chamber for directing the flow of mixed liquor in the chamber, gas supply means for supplying an oxygen containing gas to the treatment chamber so as to cause a continuous semi-circular flow pattern of mixed liquor in the treatment chamber; inlet means for supplying raw sewage to the first unit of the series; outlet means for withdrawing clarified effluent from the last unit of the series; and fluid communication means for providing fluid communication between an intermediate top portion of each successive unit of the series.