WASTEWATER TREATMENT APPARATUS AND WASTEWATER TREATMENT METHOD

PROBLEM TO BE SOLVED: To provide a wastewater treatment apparatus and a wastewater treatment method which can perform high load nitrification of wastewater containing nitrogen which enables miniaturization of equipment and reducing a total cost.SOLUTION: The wastewater treatment apparatus including a nitrification tank 2 filled up with a carrier 5 to which nitrifying bacteria is made to adhere and which can be sealed, a feed line 10 of high concentration oxygen gas in a gas phase part 12, a discharge line 11 discharging an exhaust gas from the gas phase part 12, and an aeration means 15 having a blower 9 aerating the gas of the gas phase part 12 in the nitrification tank 2 into a liquid phase and an air diffuser 8, which carries out oxidation treatment of NH-N and/or O-N in wastewater to NObiologically, includes a dissolved oxygen detecting means 13 in a liquid phase in the nitrification tank 2, a means 16 controlling the aeration air flow of the aeration means 15 so that the dissolved oxygen concentration is maintained to a set value by a result of the dissolved oxygen detecting means 13, and an oxygen detecting means 14 detecting the oxygen concentration of the gas phase part 12 in the nitrification tank 2, and a means 18 for controlling the amount of the high concentration gas supplied from the feed line 10 so that the oxygen concentration may be maintained to a prescribed range by the detected result of the oxygen detecting means 14.