Patent ID: 9630865
Date: 2017-04-25
CPC Classifications: B01J,B09C,C02F,Y02W

Claim:
1. A method of removing soluble BOD and ammonium from wastewater comprising: a. directing mixed liquor or activated sludge from an activated sludge system to a tank; b. directing the wastewater to be treated to the tank and mixing the wastewater with the mixed liquor or activated sludge to form a mixed liquor stream; c. directing the mixed liquor stream to a ballasted flocculation system; d. injecting zeolite ballast into the mixed liquor stream in the ballasted flocculation system and mixing the zeolite ballast with the mixed liquor stream; e. biologically removing the soluble BOD in the mixed liquor stream in the ballasted flocculation system; f. removing ammonium from the mixed liquor stream through an ion exchange process where ions associated with the zeolite ballast are replaced by ammonium; g. removing suspended solids from the mixed liquor stream in the ballasted flocculation system by causing suspended solids in the mixed liquor stream to agglomerate around the zeolite ballast; h. separating the zeolite ballast having the ammonium ions and suspended solids associated therewith from the mixed liquor stream and producing a clarifying effluent; i. injecting microsand into the mixed liquor stream, and wherein both microsand and zeolite function as a ballast to facilitate the settling of suspended solids; j. wherein the ballasted flocculation system includes a settling tank and wherein the method includes: k. directing at least a portion of the separated zeolite to a zeolite regeneration unit and regenerating the zeolite; and returning at least a portion of the regenerated zeolite to the ballasted flocculation system.