ADVANCED WASTEWATER TREATMENT APPARATUS FOR REMOVING PHOSPHORUS BY ELECTROLYSIS AND CULTIVATING DENITRIFYING AND NITRIFYING BACTERIA IN ANOXIC TANK AND MULTISTAGE AERATION TANK AND METHOD FOR TREATING WASTEWATER USING THE SAME

摘要

PURPOSE: To provide an advanced wastewater treatment apparatus capable of simultaneously treating organic matter, nitrogen and phosphorus highly efficiently at low cost in a medium to small sized facility in which quality and flow rate of influent are severe, and a method for treating wastewater using the apparatus. CONSTITUTION: The advanced wastewater treatment apparatus comprises a flow equalization tank for equalizing a flow amount of influent; a mixing tank(3) for uniformly mixing the influent, internal return water from the aeration tank(7) and return sludge from a first sedimentation tank(6); an anoxic tank(4) for reducing nitrate nitrogen into nitrogen gas using denitrifying bacteria; a deaeration tank(5) for removing residual organic matter and residual denitrifying gas in influent from the anoxic tank; a first sedimentation tank(6) for separating sludge and supernatant liquid from the influent by settling sludge contained in the influent from the deaeration tank; a multistage aeration tank(7) consisted of two or more tanks in which a fixed microbial contactor is installed to nitrify ammonia nitrogen in supernatant liquid flown in from the first sedimentation tank using nitrifying bacteria adhered to the microbial contactor; and a final sedimentation tank(8) for settling sludge contained in the influent from the multistage aeration tank, wherein the first sedimentation tank comprises a return unit(10) for turning some of settled sludge back to the mixing tank, and a final stage aeration tank of the multistage aeration tank comprises a return unit for internally turning some of the nitrified influent back to the mixing tank and an electrolysis unit(9) for removing phosphorus.