WASTE WATER TREATMENT APPARATUS FOR REMOVING NITROGEN AND PHOSPHORUS IN SIDE STREAM AT MINIMUM COST AND WASTEWATER TREATMENT METHOD USING THE SAME

摘要

PURPOSE: To provide a wastewater treatment apparatus and method capable of effectively removing nitrogen and phosphorus in the side stream at the minimum cost and through the minimum facility modification by modifying a side stream transfer line only without additional facility and equipment for treating the side stream, thereby using existing aeration tank. CONSTITUTION: In a wastewater treatment apparatus comprising first sedimentation basin (10), aeration tank (12), second sedimentation basin (14), sludge return line (15), thickening tank (16), digestion tank (18) and dewatering tank (20), the wastewater treatment apparatus comprises first side stream return line (21) for transferring side stream containing a thickening tank supernatant generated in the thickening step, a digestion tank supernatant generated in the digestion step and a dewatered filtrate generated in the dewatering step to the aerobic tank for side stream treatment; an aerobic tank for side stream treatment (22) for removing organic matter and phosphorus in the side stream and performing nitrification on the side stream; an anoxic tank for side stream treatment (24) for performing nitrification on treated water passing through the aerobic tank for side stream treatment; and second side stream return line (25) for transferring the treated water passing through the aerobic tank for side stream treatment to the first sedimentation basin.