Patent ID: 7407582

Claim:
A method of treating wastewater utilizing an activated sludge process and a ballasted flocculation process, comprising: directing a first wastewater stream to an activated sludge system having at least one reactor and a clarifier; returning activated sludge from the clarifier to the reactor and mixing the activated sludge with the first wastewater stream to form mixed liquor, and directing the mixed liquor to the clarifier where the clarifier separates the activated sludge from clarified effluent; directing a second wastewater stream to a mixing chamber; directing mixed liquor or activated sludge from the activated sludge system to the mixing chamber, and mixing the mixed liquor or activated sludge with the wastewater from the second stream; directing mixed liquor from the mixing chamber to a ballasted flocculation system having one or more mixing zones and a settling zone; and mixing insoluble granular material with the mixed liquor passing through the ballasted flocculation system and separating sludge from clarified effluent in the settling zone.