Purpose for Odor Control Basis of Control Hydrogen peroxide may be used in both mist scrubbers and packed tower scrubbers as a replacement for sodium hypochlorite (bleach). Like bleach, the process involves two concurrent mechanisms: 1) absorption of the odors (H2S) into the alkaline scrubbing solution; and 2) oxidation of the absorbed sulfide in solution. There is also in practice a process which uses H2O2 in series with bleach to scrub composting odors. This process relies on a series of three packed tower scrubbers: the first is a pH neutral water wash (to remove ammonia and amine odors); the second uses a conventional caustic/bleach solution in which the bleach is purposely overdosed (to oxidize the complex organic sulfur odors); and the third uses a caustic/H2O2 solution (to remove the unreacted chlorine vapors carried over from the second stage).