PROCESS FOR REMOVING PHOSPHATE FROM BOD-CONTAINING WASTEWATER TO PRODUCE A SUBSTANTIALLY PHOSPHATE-FREE EFFLUENT

摘要

Activated sludge wastewater treatment process for removing phosphate from BOD-containing wastewater in which phosphate-enriched sludge formed in the aeration zone is settled in a phosphate stripping zone under anaerobic conditions to cause release of phosphate from the sludge solids. The released phosphate is countercurrently stripped from the sludge in the stripping zone by a low phosphate, low solids stripping medium to provide phosphate-lower sludge for recirculation to the aeration zone.