| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for treating nitrogen-containing water biologically, in which the treated water having stable quality can be secured even when the concentration of nitrogen in the water to be treated or the flow rate of the water to be treated is fluctuated. <P>SOLUTION: The method for treating the nitrogen-containing water biologically comprises a step of intermittently adding a hydrogen donor to a reaction tank, into which the water that is to be treated and includes nitric acid or nitrous acid is made to flow, to reduce the nitric acid or nitrous acid into nitrogen gas. The addition rate (v) of the hydrogen donor is set so as to satisfy expression: v=X×T×(100-D)/(N×S<SB>T</SB>×D×M) (wherein X is the amount of the hydrogen donor to be added per unit time; T is hydraulic residence time; N is a number of intermittent addition cycles of the hydrogen donor; M is the concentration of the hydrogen donor to be added; D is the ratio of the addition time of the hydrogen donor to the time of one cycle of intermittent addition of the hydrogen donor; S<SB>T</SB>is the time to stop the hydrogen donor in the time of one cycle of intermittent addition of the hydrogen donor). <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
