Patent ID: 6645386
Filing Date: 2003-11-11
Classification: B01D,B03B,B04C,C02F

Abstract:
A method of treating water or wastewater comprising:a. treating the water or wastewater in a treatment facility by a ballasted flocculation process which produces sludge containing granular material; b. directing the sludge into a circular grit trap having a cylindrical section, a conical section, and an upflow outlet, and separating substantial sludge from the granular material as the sludge moves around the cylindrical and conical sections of the circular grit trap, and wherein the separated sludge is discharged through the upflow outlet; c. directing the remaining sludge and granular material from the conical section into a washing chamber; d. injecting an auxiliary liquid into the chamber and washing the granular material to further separate sludge from the granular material; e. directing the sludge separated from the granular material in the chamber back up through the grit trap and out the upflow outlet; and f. directing the separated granular material from the chamber and recycling the separated granular material back to the treatment facility.