PURPOSE: To remarkably restore the activity of a catalyst, by washing the catalyst used in the oxidizing treatment of the noxious component in waste water with an aqueous oxidizing agent solution before washing the same with water.
CONSTITUTION: A catalyst is formed of a metal alone usually used in oxidizing reaction belonging to a ferrous group VIII, a platinum group VIII, a copper metal groups I b or a chrominum group VIa or a water-insoluble or hardly water-soluble compound of said metal or one prepared by supporting said metal or said metal compound by a carrier such as alumina. This catalyst is used in the oxidizing treatment of the noxious components such as the COD component, the suspended org. substance or ammonia in waste water while the catalyst lowered in its activity is washed with an aqueous solution of an oxidizing agent such as hydrogen peroxide to mainly remove the org. substance adhered to the surface of the catalyst and, thereafter, washed with water. As a result, the activity of the catalyst can be restored remarkably.
YOKOMAKURA TAKAO
MIZUNO KENJI
HIBINO YASUSHI