Abstract: Wastewater treatment systems are disclosed with improved aeration tanks. The aeration tank includes an inverted frusto-conical clarifier and a submersible aerator pump disposed between the bottom of the aeration tank and the interior of the clarifier. The pump is connected to an air inlet line that can pass downward through the clarifier. A plurality of bubble outlet lines extend outward from the pump radially and tangentially towards the sidewall of the aeration tank. Bubbles rise upward through the aeration space disposed outside of the clarifier and around the aeration space or around the clarifier for improved mixing. The system may include a baffled pretreatment tank and/or pump tank The slopes of the sidewalls of these tanks are of the same magnitude but opposite to that of the aeration tank thereby enabling tank nesting. Methods of retrofitting water treatment systems and treating wastewater are disclosed.

Abstract: Wastewater treatment systems are disclosed with improved aeration tanks. The improved aeration tank includes an inverted frusto-conical clarifier and a submersible aerator pump disposed between the bottom of the aeration tank and the interior of the clarifier. The aerator pump is connected to an air inlet line that can pass downward through the clarifier and a plurality of bubble outlet lines that extend outward from the pump both radially and tangentially towards the sidewall of the aeration tank. As a result, bubbles rise upward through the aeration space disposed outside of the clarifier and around the aeration space or around the clarifier for improved mixing. The system may also include additional tanks such as a pretreatment tank and pump tank which are designed with baffled sidewalls for anchoring purposes.