TECHNOLOGY FOCUS - ENVIRONMENT - Preferred Methods: The initial tank is operated as an Anoxic Reactor and the downstream tank is operated as an Aerobic Reactor. The treatment process is a 2-stage activated sludge process, conventionally termed as Modified Ludzak Ettenger Process, for (1) fermenting proteins in the wastewater to liberate ammonia and removing carbonaceous Biological Oxygen Demand by biological synthesis while the wastewater is within the Anoxic Reactor, (2) oxidizing the ammonia to form nitrate ions while the wastewater is within the Aerobic Reactor, and (3) reducing the nitrate ions to form nitrogen gas while the wastewater is within the Anoxic Reactor, whereby substantial denitrification of the throughput wastewater occurs. The backward recycling from the Aerobic Reactor to the Anoxic Reactor is 4-8 times the input rate; and the mixed liquor discharges from the Anoxic Reactor to the Aerobic Reactor, the discharging being 5-9 times the input rate.The mixed liquor discharges from the Aerobic Reactor to a clarifier (32) at 1.5-3 times the input rate; and the clarifier discharges clarified liquor and sludge, a portion of the sludge being recycled to the Aerobic Reactor at 0.5-2 times the input rate.A nitrate-rich recycle flow rate from the Aerobic Reactor to the Anoxic Reactor which is 400-800% of the input rate is utilized in combination with the return of activated sludge from the clarifier to the Anoxic Reactor, resulting in a nitrate removal efficiency of 82-91% without consuming additional energy for operation of a separate nitrate recycle pump or pumps. The process is a 3-stage activated sludge process for treating wastewater, conventionally termed as Biological Phosphorus Process.The mixed liquor discharges from the Aerobic Reactor to the clarifier at 1.5-3 times the input rate, enabling polyp bacteria to proliferate while in the Aerobic Reactor, metabolize the stored intracellular compounds for growth and energy, and remove large quantities of phosphate from solution with excess energy during a luxury uptake stage. Large quantities of phosphorus are removed from the process in the wasted portion of the sludge, and a stream of clarified liquor discharged by the clarifier contains substantially smaller quantities of nitrogen and phosphorus as compared to the stream of throughput wastewater.Preferred Components: The Anaerobic Reactor and Anoxic have a jet manifold, disposed at its bottom for mixing its contents, and a dual-use jet recirculation pump which is flow connected to the Anaerobic Reactor for withdrawing selected amounts of mixed liquor, and is also flow connected to the Anoxic Reactor for withdrawing selected amounts of mixed liquor, and is additionally flow connected to the jet manifold within the Anaerobic Reactor for feeding the withdrawn mixed liquors.