BIOLOGISK BEHANDLING – KVÄVEREDUKTION Utformning av anoxzoner och dimensionering av omrörningsutrustning / Biological Treatment-Nitrogen Reduction Design of Anoxic Zones and Sizing of Mixing Equipment
Nitrogen reduction by denitrification in anoxic zones is increasingly used worldwide within activated sludge processes (Phosphorus removal in anaerobic zones have similar requirements). Mixing is a necessary base for good process results and involves several contradicting requirements. The design of the zones and the mixing equipment should, when possible, be done simultaneously to achieve good process results, economy and flexibility. Today there are no good objective methods for mixing design within anoxic zones. This paper is concentrated on: (a) Mixing requirements: Avoid settlings, secure contact homogenizing, maximum shear rate, minimum oxygenation, mixing time and sludge quality. “Complete abstract not presented.”