METHOD FOR NITRIFYING WASTEWATER USING MICRO-ORGANISMS ISOLATED AND ENRICHED FROM AMMONIUM-BASED WATER

摘要

PCT No. PCT/SE98/00120 Sec. 371 Date Jul. 29, 1999 Sec. 102(e) Date Jul. 29, 1999 PCT Filed Jan. 28, 1998 PCT Pub. No. WO98/33745 PCT Pub. Date Aug. 6, 1998The present invention comprises a method for biological oxidation of nitrogen in water, e.g., wastewater, nitrification, by using ammonia-rich water for the selection and enrichment of nitrifying micro-organisms in a separate aerated reaction volume, where organic matter already has been reduced. The nitrifying micro-organisms will get a competing edge compared to other species, as they are being able to obtain energy from the oxidation of ammonia into nitrate. The method can be applied to the activated sludge process by the introduction of a sludge aeration zone on the recycled sludge, and also be combined with a sludge anoxic zone, for denitrification, enabling a more reliable operation of biological nitrogen as well as phosphorus removal, by maximal use of reaction volumes with lower detention time and lower costs. It can also be applied to a fixed bed process. The possibility of stimulating the micro-organisms to higher activity by changing the physical-chemical conditions is also included, as well as improving the sludge separation characteristics. The method is enabling an overall view of the process, integrating different process stages for optimisation and best possible operational results.