To simply remove catalyst poisons from a metal catalyst which has been poisoned by metals such as copper, and regenerate the catalyst by bringing the catalyst suffering from deterioration of activity into contact with an ammonia-containing waste water to which an oxidizing agent has not been added.
Ammonia-containing waste water received in a crude water tank 1 is transferred to an adjustment tank 3 by means of a pump 2, and a pH controlling agent is added as necessary, and a sodium nitrile aqueous solution is injected from an oxidizing agent tank 5 in the above process and then temperature is adjusted before ammonia nitrogen is decomposed in a catalyst packed tower 9. When activity of the metal catalyst in the catalyst packed tower 9 is deteriorated, a pump 6 is stopped and injection of the oxidizing agent is stopped, and a valve 11 is closed, and a valve 12 is opened, and the ammonia containing waste water, into which the oxidizing agent has not been added, is introduced into the catalyst packed tower 9. The metal catalyst is regenerated and copper contained in the ammonia containing waste water used for regeneration of the metal catalyst is simultaneously removed before the waste water is returned to the crude water tank 1. As described above, the metal catalyst is regenerated in the process of treating the ammonia containing waste water in a short period of time and treatment can be restarted.
TAKABAYASHI YASUHIKO
NAKAHARA TOSHIJI
