| 摘要 |
PROBLEM TO BE SOLVED: To stably remove ammoniacal nitrogen in waste water containing metal components over a long period of time by adjusting the pH of the waste water to a specified range and passing the waste water through a column packed with cation exchange resin particles when the waste water is treated by catalytic wet oxidation treatment. SOLUTION: Waste water in a waste water storage tank 2 is transported by a pump 8 to a pipe 4. During the transport, the pH of the waste water is adjusted to 9-12 by adding an alkali with an alkali adding mechanism 10 to separate metal components in the waste water as hydroxides. The waste water is transported to a column 20 packed with cation exchange resin particles, where the separated metal hydroxides and suspended solids are captured and ionic metal components which remain as metal hydroxides without separating are adsorbed. The waste water is then successively transported to a heat exchanger 6, a heater 12 and an ammoniacal nitrogen removing unit 14, and ammoniacal nitrogen in the waste water is removed. The pressure difference before and after passing the column 2 is measured with a differential pressure gauge 22 and backward washing is carried out, if necessary. |
