Wastewater Treatment System

Abstract

A system and method for treating wastewater includes two or more biological reaction zones separated by chamber walls. The system and method for treating wastewater includes static recycle of a mixed liquor from a second biological reaction zone to a first biological reaction zone.

What is claimed is: 
     
         1 .- 25 . (canceled) 
     
     
         26 . A method for retrofitting an oxidation ditch having multiple adjacent moving biological reaction zones, the biological reaction zones sharing a common intermediate chamber wall, comprising:
 positioning at least one opening in the common intermediate chamber wall; and   positioning a baffle along the common intermediate chamber wall and adjacent to the opening to statically recycle the mixed liquor from an inner biological reaction zone to an outer biological reaction zone through the opening at a rate of two to four times an influent flow rate to the outer biological reaction zone.   
     
     
         27 . The method according to  claim 26 , wherein the biological reaction zones are concentric. 
     
     
         28 . The method according to  claim 26 , wherein the baffle is positioned at a predetermined location on the common intermediate chamber wall. 
     
     
         29 . The method according to  claim 26 , further comprising controlling the baffle angle based on a measured nitrogen content of an effluent stream. 
     
     
         30 . A wastewater treatment system comprising:
 multiple adjacent biological reaction zones, the biological reaction zones sharing a common intermediate chamber wall having at least one opening; and   a baffle secured to the common intermediate chamber wall adjacent the opening at an angle to the common intermediate chamber wall, the baffle projecting into an inner zone of an inner biological reaction zone.   
     
     
         31 . The system according to  claim 30 , wherein the biological reaction zones are concentric. 
     
     
         32 . The system according to  claim 31 , wherein the biological reaction zones are in a racetrack configuration. 
     
     
         33 . The system according to  claim 31 , wherein the biological reaction zones are in a circular configuration. 
     
     
         34 . The system according to  claim 30 , wherein the baffle is placed at a 45° angle to the center of the inner biological zone. 
     
     
         35 . The system according to  claim 30 , wherein the opening and the baffle are sized and shaped to statically redirect a second mixed liquor from an inner biological reaction zone to an outer biological reaction zone at a rate of two to four times an influent flow rate to the outer biological reaction zone. 
     
     
         36 . A wastewater treatment system comprising:
 multiple concentric biological reaction zones, the biological reaction zones sharing a common intermediate chamber wall having at least one opening;   an influent stream fluidly connected to a wastewater source and an outer biological reaction zone of the wastewater treatment system;   a baffle secured to the common intermediate chamber wall, the baffle projecting into an inner portion of an inner biological reaction zone of the wastewater treatment system; and   an effluent stream fluidly connected to an inner biological reaction zone and a downstream point.   
     
     
         37 . The system according to  claim 36 , further comprising an aerator. 
     
     
         38 . The system according to  claim 36 , wherein the baffle is placed at a 45° angle to the center of the inner biological reaction zone. 
     
     
         39 . The system according to  claim 36 , wherein the opening and the baffle are sized and shaped to statically redirect a second mixed liquor from the inner biological reaction zone to an outer biological reaction zone.