| 摘要 |
<p>PURPOSE:To proceed biological denitrification reaction effectively by providing an evacuation degasification apparatus for removing gaseous oxygen contained in the water to be treated between a biological nitrating tank and a succeeding biological denitification tank. CONSTITUTION:N-compd. contg. water W to be treated is fed to a nitrating tank 1 comprising rotary disks 4 through a feeding passage 6. The N-compd. is oxidized there to HNO3 or HNO2 by the effect of microorganisms sticking to the surface of the rotary disks 4. Discharged water from the nitrating tank 1 is once fed to an evacuation degassing apparatus 9 and the apparatus 9 is held at evacuated state by a vacuum pump 11 to liberate dissolved gas and bubbles contained in the water to be treated. Then, a source material comprising org. hydrocarbon is added from an injecting device 8 into the water to be treated W, and the water is fed to a denitrification tank 7. Thus, HNO3 and HNO2 are reduced by the effect of denitrification bacteria, and gaseous N2 is liberated.</p> |
