Patent ID: 6685834
Filing Date: 2004-02-03
Classification: C02F,Y02W

Abstract:
A method for digesting, conditioning and dewatering sludge comprising:a. directing sludge to an autothermal thermophilic aerobic digester (ATAD) and subjecting the sludge to an ATAD digestion process; b. directing the ATAD digested sludge to a mesophilic aerator and subjecting the digested sludge to mesophilic aeration; c. after the ATAD sludge has been subjected to mesophilic aeration, mixing with the sludge a metal salt selected from the group consisting of ferric chloride, ferrous chloride, and alum; d. mixing a cationic polymer with the sludge and wherein the metal salt along with the cationic polymer forms conditioned sludge; and e. directing the conditioned sludge to a dewatering station and dewatering the sludge.