Patent ID: 8372274

Claim:
A wastewater treatment system, comprising: a hollow, elongate, cylindrical body made from high-density polyethylene, the cylindrical body having reinforcement ribs formed by a helically wound steel band embedded in the high-density polyethylene and extending between opposite ends of the elongate cylindrical body; end members extending across and covering the opposite ends of the cylindrical body, the end members and the cylindrical body forming a watertight tank defining at least one chamber adapted for treatment of wastewater, the tank being oriented vertically; an inlet pipe extending into the tank adapted for admitting wastewater into the tank, the inlet pipe consisting of a single inlet pipe; an outlet pipe extending from the tank adapted for discharging treated wastewater from the tank, the outlet pipe consisting of a single outlet pipe; first and second partition walls dividing said tank into three chambers, including: an anoxic first chamber adapted for housing bacteria, said inlet pipe extending into the first chamber, wherein the bacteria is selected from the group consisting of anaerobic bacteria and facultative bacteria; a second chamber forming a bioreactor adapted for housing aerobic bacteria; a third chamber forming a clarifier, said outlet pipe extending from the third chamber; a first conduit extending between the first chamber and the second chamber for passing partially treated wastewater from the anoxic chamber to the bioreactor chamber; and a second conduit extending between the second chamber and the third chamber for passing partially treated wastewater from the bioreactor chamber to the clarifier chamber; a first effluent filter disposed in the anoxic first chamber for filtering undigested organic matter in the partially treated wastewater before passing the partially treated wastewater to the bioreactor chamber; a source of pressurized air; an air conduit extending from the source of pressurized air into the bioreactor chamber; an air diffuser connected to the air conduit, the diffuser being disposed in the bioreactor chamber and producing a stream of air bubbles; a fixed film assembly disposed in the bioreactor chamber for supporting growth of the aerobic bacteria; a return activated sludge pump disposed in the clarifier chamber for feedback of activated sludge from the clarifier chamber to the anoxic first chamber for further wastewater treatment; and siphon-ejection air lift assembly disposed in the clarifier chamber for feedback of surface scum from the clarifier chamber to the bioreactor chamber, the siphon-ejection assembly including a air lift pump and needle valve block for air flow rate adjustment.