| 摘要 |
PURPOSE: A method for removing nitrogen from wastewater is provided to drastically and physically remove the nitrogen from the wastewater by subdividing wastewater particles with circulating the wastewater inside a flow path causing the cavitation of a fluid in a storage tank, and simply control a process for removing the nitrogen from the wastewater by controlling pressure inside the tank and vacuum pressure at the outlet of the flow path through temperature control. CONSTITUTION: A method for removing nitrogen from wastewater makes the wastewater flow inside a closeable tank and circulates the wastewater along a flow path connected to the tank in a purification-discharge process for livestock excretions and organic waste. A venturi tube(500) inside the flow path has a body(510), an inlet(520), and a spiral groove(550). The spiral groove is formed at the inner circumferential surface of a hollow(512) at the inlet of the body, and the width of the spiral groove becomes larger from the inlet to the center of the hollow, so that the wastewater flowing through the inlet is converted into a vortex and enhance turbulence and swirling when the wastewater passes inside the venturi tube. Particles are subdivided so that the temperature of the wastewater is raised when the wastewater passes inside the venturi tube. The raised temperature of the wastewater is maintained into 30 to 60>= through a heat exchanger, and pressure at the outlet of the flow path is maintained into less than 0.096 MPa, so that a condition for microorganism activity inside the livestock excretions and the organic wastes is satisfied. The pressure range of the tank is controlled to be 5 to 7 bars in order to control the particle subdivision rate of the particles, so that nitrogen removal rate due to ammonia stripping is controlled by cavitation due to particle subdivision. |
