Abstract: The rejuvenative catalytic oxidation of offensive substances, such as cyanides, sulfides, sulfites, thiosulfates, mercaptans, disulfides, ammonia and mixtures thereof, contained in waste water. The process involves the addition of a low concentration of a metal compound to the waste water to be treated and then passing the waste water along with a source of oxygen over an adsorbent material, thus catalytically oxidizing the offensive substances contained in the waste water. The process reduces the catalytic impact of the loss of metal from the adsorbent material due to leaching and allows the catalyst to be rejuvenated and allows recovery from process upsets in the treating system without unit shutdown and catalyst replacement. An example of the catalytic support is activated carbon and an example of the metal is copper.