Process for biological sewage purification

US4786413A · kind A · utility

Assignee

• Linde GmbH · DE

Inventors

• Hans Reimann · Ebenhausen, DE
• Uwe Fuchs · Munich, DE

Key dates

• Filing date: Jan 21, 1987
• Grant date: Nov 22, 1988
• Expiry date: Jan 21, 2007

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S210/903
• WIPO field: Environmental technology
• WIPO sector: Chemistry

Abstract

In a process for the biological sewage purification of sewage containing organic as well as nitrogen-containing pollutants, carbon decomposition and nitrogen removal are performed. The sewage is gassed with air and/or pure oxygen in a reactor in the presence of a biomass fixed on a support material and then, in a secondary sedimentation step, is separated into purified water and sludge. The sludge is at least partially recycled into the reactor. Particles of support material in lumpy and/or granulated form and in free-flowing quantities are employed in the reactor as support material for the microorganisms. To attain both a high carbon and a high nitrogen decomposition at the same time, the reaction is provided with BOD.sub.5 volume load of 0.4 to 2.5 kg/m.sup.3 d and a TKN volume load of 0.1 to 0.8 kg/m.sup.3. d, BOD.sub.5 decomposition, nitrification and denitrification are all performed within an undivided reactor, in which the O.sub.2 concentration within the liquid is 0.5 to 4 mg/l and the support material occupies 15 to 35% of the reactor volume.