Sewage treatment process

Abstract

Abstract THERE IS DISCLOSED AN ACTIVATED SLUDGE SEWAGE TREATMENT PROCESS WHICH COMPRISES MIXING INFLUENT SEWAGE MATERIAL WITH ACTIVATED SLUDGE TO PROVIDE A MIXED LIQUOR. THE MIXED LIQUOR IS PASSED TO AN AERATION ZONE WHEREIN IT IS AERATED TO REDUCE THE BOD CONTENT THEREOF AND TO CAUSE THE MICROORGANISMS PRESENT TO TAKE UP PHOSPHATE. THE MIXED LIQUOR IS THEN PASSED TO A SETTLING ZONE CONTAINING AN ANAEROBIC LAYER OF SLUDGE. IN THE SETTLING ZONE, PHOSPHATE-ENRICHED SLUDGE, IN WHICH THE PHOSPHATE IS PRESENT IN THE CELLS OF THE ORGANISMS, SETTLES INTO THE ANAEROBIC LAYER OF SLUDGE AND A SUBSTANTIALLY PHOSPHATE-FREE EFFLUENT IS REMOVED FROM ABOVE THE LAYER OF SLUDGE. THE SLUDGE IS MAINTAINED UNDER ANAEROBIC CONDITIONS IN THE SLUDGE LAYER OF THE SETTLING ZONE FOR A TIME SUFFICIENT TO CAUSE THE ORGANISMS IN THE SLUDGE TO RELEASE PHOSPHATE TO THE LIQUID PHASE OF THE SLUDGE. SLUDGE CONTAINING SOLUBLE PHOSPHATE IN THE LIQUID PHASE THEREOF IS REMOVED FROM THE SETTLING ZONE. THE SLUDGE IS THEN TREATED TO SEPARATE A PHOSPHATEENRICHED AQUEOUS PHASE AND TO PROVIDE A SLUDGE HAVING A HIGHER CONCENTRATION OF SOLIDS AND A LESSER CONCENTRATION OF PHOSPHATE. THE CONCENTRATED SLUDGE IS RECYCLED FOR MIXING WITH INFLUENT SEWAGE MATERIAL IN THE ACTIVATED SLUDGE SEWAGE TREATMENT PROCESS.

Inventors

• 👤 G Levin
• 👤 G Topol

Bibliographic Details