David A Beula

US Patent:

47494921, Jun 7, 1988

Filed:

Jul 6, 1987

Appl. No.:

7/069981

Inventors:

John K. Berrigan - Wausau WI
David A. Beula - Schofield WI
William M. Copa - Wausau WI

Assignee:

Zimpro/Passavant - Rothschild WI

International Classification:

B03D 306
C02F 308
C02F 128

US Classification:

210616

Abstract:

Regenerated adsorbent particles, such as activated carbon, are recovered from a wet oxidation-regenerated mixed liquor sludge from a wastewater treatment system by diluting and settling a blowdown slurry from the wet oxidation reactor to obtain a first aqueous phase containing primarily regenerated adsorbent particles and fine ash particles and a first solids phase containing primarily grit particles. The first aqueous phase is combined with a portion of the regenerated adsorbent particle slurry withdrawn from the upper portion of the wet oxidation reactor and, after treatment with a dispersing agent and then an anionic flocculating agent, the resulting mixture is settled to obtain a second aqueous phase containing primarily fine ash particles and a second solids phase containing primarily regenerated adsorbent particles. The second solids phase is recycled to the treatment system for reuse and, after treatment with a cationic flocculating agent, the second aqueous phase is settled to obtain a substantially particle-free third aqueous phase and a third solids phase containing primarily fine ash particles. Slurries containing the grit and fine ash particles are combined and dewatered prior to disposal.