Patent ID: 6783671
Filing Date: 2004-08-31
Classification: C02F,Y02W

Abstract:
An activated sludge wastewater treatment apparatus for use in a wastewater treatment facility including an aeration vessel having a plurality of aeration zones, a settling vessel, and a digestion vessel, said apparatus comprising:said aeration vessel having approximately 20 percent to 45 percent of its total volume comprising one or more reaeration zones; a sludge return line to transport activated sludge from said settling vessel to said one or more reaeration zones; the return activated sludge flow rate being less than 60 percent of the wastewater influent flow rate; a supernatant return line for adding supernatant from said digestion vessel to said one or more reaeration zones; and wherein the concentration of mixed liquor suspended solids in said aeration vessel is maintained so that the ratio of MLSS between said reaeration zones and the other aeration zones is greater than 1:1; and wherein the average influent volumetric loading capacity is greater than approximately 3.2 kg BOD5/m3day.