NOVELTY - Treating waste water by utilizing nitrobacteria involves transferring transferring water obtained from sludge of Harbin Taiping region to laboratory and incubating at 6-10 degrees C in culture medium. Culture medium comprises glucose (200-500mg/L), ammonium chloride (50-100mg/L), sodium bicarbonate (300-1000mg/L) and nutrient solution. Nutrient solution comprises calcium carbonate (1.0 g/L), potassium monohydrogen phosphate (0.75g/L), manganese sulfate (0.01g/L) and manganese (II) sulfate hydrate (0.03g/L).    USE - Method for treating waste water (claimed).    ADVANTAGE - The method enables treatment of waste water in an eco-friendly and economic manner.    DETAILED DESCRIPTION - Treating waste water by utilizing nitrobacteria involves transferring water obtained from sludge of Harbin Taiping region to laboratory and incubating at 6-10 degrees C in culture medium. Culture medium comprises glucose (200-500mg/L), ammonium chloride (50-100mg/L), sodium bicarbonate (300-1000mg/L) and nutrient solution. Nutrient solution comprises calcium carbonate (1.0 g/L), potassium monohydrogen phosphate (0.75g/L), manganese sulfate (0.01g/L) and manganese (II) sulfate hydrate (0.03g/L). Nitrification medium for bacterial is isolated using a modified Stephenson medium. Nitrifying bacteria are isolated and are placed at 4 degrees C in an incubator. Colonies of bacteria are selected to grow well in an acclimated culture. Nitrifying bacteria in nitrosation broth are centrifuged at 4000 revolutions per minutes for 15 minutes. Supernatant is discarded, and pellet is washed twice with phosphate buffer (pH is 7.2). The pellet is washed thrice in physiological saline, and then centrifuged, and then supernatant is discarded. Distilled water is added to a cold-resistant bacteria suspension. Sodium alginate is taken as the immobilization material that involves embedding method and adsorption method. Polyvinyl alcohol is taken as the immobilization material that comprises embedding method or adsorption method. Vermiculite is used as immobilized material to obtain immobilized nitrifying bacteria products.