METHOD FOR ELIMINATING NITROGEN USING GRANULE OF NITRIFYING MICROORGANISMS TO REDUCE CONSUMPTION OF OXYGEN REQUIRED FOR NITRIFICATION

摘要

PURPOSE: To substantially reduce consumption of oxygen required for nitrification and amount of organic matter required for denitrification and reduce volume of biofilm reactor by eliminating nitrogen from sewage and wastewater using granule of nitrifying microorganisms predominantly containing ammonia oxidizing bacteria. CONSTITUTION: The method comprises a step (a) of preparing granule of nitrifying microorganisms in which ammonia oxidizing bacteria are predominantly distributed by checking the growth of nitrite oxidizing bacteria in a nitrifying microorganism granule reactor; a nitrifying step (b) of oxidizing ammonia nitrogen into nitrate-nitrogen by flowing the granule of the nitrifying microorganisms into a nitrifying tank; a denitrifying step (c) of converting nitrate-nitrogen into nitrogen gas (N2) using denitrifying microorganisms by flowing wastewater containing the nitrate-nitrogen obtained in the nitrifying step into a denitrifying tank; and a step of transferring a denitrified mixed solution to a secondary settling chamber so that the denitrified mixed solution is separated into treated water and microorganism sludge, returning some of the microorganism sludge to the nitrifying tank or the nitrifying microorganism granule reactor, and passing the other some of the microorganism sludge through thickening, digestion and dewatering processes so that the treated sludge is disused.